Hippotherapy

Number: 0151

Policy

Aetna considers the use of hippotherapy (also known as equine therapy) experimental and investigational for the treatment of the following indications and all other indications because there is insufficient scientific data in the peer reviewed medical literature to support the effectiveness of hippotherapy for the treatment of individuals with these indications:

• Alzheimer's disease
• Anxiety
• Attention deficit and/or hyperactivity disorder
• Autism
• Behavioral and psychiatric disorders (including aggressive violent behavior and eating disorders)
• Cerebral palsy or other motor dysfunctions (e.g., arthritis, balance deficits, children with psychomotor impairment, head injury, multiple sclerosis, spinal cord injury, and stroke)
• Childhood obesity
• Chronic pain (including low back pain)
• Developmental delays
• Down's syndrome
• Post-traumatic stress disorder
• Rehabilitation of cancer survivors
• Sexual abuse and emotional stress
• Substance abuse disorder.

Background

Cerebral palsy (CP) also known as static encephalopathy, refers to a wide variety of non-progressive brain disorders resulting from insults to the central nervous system during the perinatal period.  The management of the motor dysfunction of patients with CP includes the conventional orthopedic approach of range of motion, stretch, and strengthening, as well as neurodevelopmental treatment.  A general objective of physiotherapy for children with CP is to reduce the influence of abnormal muscle tone and facilitate the emergence of normal postural and movement components.  For many children with CP or other motor dysfunction, physical therapy is a long and arduous process.  In order to sustain patients' interest and enthusiasm in their continuing treatment, therapists have developed adjunctive therapeutic activities such as dancing, swimming, and horseback riding.

Hippotherapy, also known as therapeutic horseback riding, equine-facilitated therapy, or horse therapy, is the passive use of the physical movements of the horse in the treatment of patients with neurological or other disabilities.  This is often performed under the direct supervision of a physical therapist or occupational therapist who is horse-knowledgeable.  By using the horse as a treatment modality, the therapist tries to facilitate normal muscle tone and inhibit abnormal posture.  The therapist may place the patient in a variety of positions on the horse such as prone across horse, prone lengthwise with hips abducted and knees flexed, side sitting, or sitting.  It is believed that the rhythmic, swinging movement of the horse enhances balance, co-ordination, and motor development.  Patients who participate in therapeutic riding include not only children with CP, but also individuals with arthritis, multiple sclerosis, head injury, and stroke.  The horse is usually led at a walking or trotting pace by a skilled equestrian to ensure safety and expert handling of the animal.  Assistants are present, usually one on each side, to help repositioning or stabilizing the patient.  For more severely disabled patients, the therapist may also serve as a back rider.

For children with CP, hippotherapy utilizes the basic principles of Rood, Bobaths (individuals who had put forth/developed neurodevelopment treatment concepts for neuromuscular dysfunction), and proprioceptive neuromuscular facilitation.  It is believed that therapeutic horseback riding can reduce spasticity, maintain and increase range of motion in the upper extremities of these children.  Haskin and colleagues (1982) described the benefits of a hippotherapy program (30 mins per week) in a 5-year old patient who has participated in this type of therapy since she was 2 1/2.  Improvements included strengthening of the back and neck, better balance, ability to sit up longer, less spasticity in the lower extremities, the legs are externally rotated and abducted, and the feet are dorseflexed.  However, the patients also swam once a week and received physical therapy for her lower extremities 6 days a week.  Thus, it is unclear whether the observed improvements were due to hippotherapy, adjunctive therapeutic swimming, intensive physical therapy, and/or the result of natural growth and development.

Using a repeated-measured design, Bertoti (1988) assessed postural changes in 11 children (4 girls and 7 boys, aged 28 to 114 months) with spastic CP after participation in a 10-week hippotherapy program (1-hour session, 2 times per week).  Evaluation of posture was carried out 3 times by 3 pediatric physical therapists –

1. pretest-1 followed by a 10-week period of no riding,
2. pretest-2 followed by a 10-week therapeutic riding program, and
3. post-test. 

A composite score for each test period was computed for each patient, and a median score was calculated for the entire group at each test period.  A statistical difference was observed among the 3 test periods with significant improvement occurring during the period of hippotherapy.  Subjective clinical improvements such as reduced hypertonicity, as well as improved weight-bearing and functional balance skills were reported by parents and referring physical therapists.  These findings represented the first objective report that hippotherapy may have beneficial effect on the posture of children with spastic CP.  However, the author concluded that further investigation is needed to isolate additional variables such as range of motion, balance, weight shift, and strength, and to evaluate the effects of hippotherapy on different disabilities.

In an article on hippotherapy, Tuttle (1987) stated that research on the effect and application of the various forms of therapeutic horseback riding is needed to refine program planning, and to support funding and third party reimbursement.  Furthermore, a workshop on "The Health Benefits of Pets" sponsored by the National Institutes of Health concluded that "solid data on the success of therapeutic riding is limited. ... Future research is indicated to compare the efficacy of therapeutic riding with other clinical treatment procedures that do not involve the horse and to validate dramatic clinical observations" (NIH, 1983).  Additionally, in an article published in the Journal of American Veterinarian Medicine Association, Potter and colleagues (1994) stated that "Lack of scientific documentation of the benefits of therapeutic riding is a major obstacle that must be overcome. ... Research is critically needed in all aspects of therapeutic riding".

Debuse et al (2005) noted that despite a substantial body of anecdotal and clinical evidence for its benefits, research evidence for hippotherapy is sparse.  In a questionnaire survey, these researchers explored the views of physiotherapists and people with CP who use hippotherapy.  This study was aimed to:

1. establish the pattern of hippotherapy practice in Germany and the U.K.;
2. examine the perceived main effects of hippotherapy on people with CP in Germany and the U.K.; and
3. investigate how these effects are being measured in both countries. 

The results highlighted considerable differences in how hippotherapy is practiced in the U.K. compared with in Germany.  In spite of this, the study revealed agreement among respondents on the overall perceived effects of hippotherapy on individuals with CP, namely, the regulation of muscle tone, improvement of postural control and psychological benefits.  The results also indicated scant use of outcome measures to evaluate these effects.

Casady and Nichols-Larsen (2004) examined if hippotherapy has an effect on the general functional development of children with CP.  The study employed a repeated-measures design with 2 pre-tests and 2 post-tests conducted 10 weeks apart using the Pediatric Evaluation of Disability Inventory (PEDI) and the Gross Motor Function Measure (GMFM) as outcome measures.  A convenience sample of 10 children with CP participated whose ages were 2.3 to 6.8 years at baseline (mean +/- SD 4.1 +/- 1.7).  Subjects received hippotherapy once-weekly for 10 weeks between pre-test 2 and post-test 1.  Test scores on the GMFM and PEDI were compared before and after hippotherapy.  The authors concluded that results of this study suggest that hippotherapy has a positive effect on the functional motor performance of children with CP.  Hippotherapy appears to be a viable treatment strategy for therapists with experience and training in this form of treatment and a means of improving functional outcomes in children with CP, although specific functional skills were not investigated.

There are 2 main drawbacks with this study:

1. the GMFM scorers were not blinded to the order of test date and they were allowed to keep the scores sheets, which may have biased the scorers, and
2. with the individualized approach to treatment, there is no protocol that would allow replication of this study. 

The authors stated that hippotherapy has the potential to be a valuable treatment strategy in treating children with CP.  Future studies should use more homogeneous patient populations in terms of age and type of CP to ascertain precise areas of function affected most by hippotherapy.

In a review on the use of complementary and alternative therapies for the treatment of children with CP, Liptak (2005) noted that although studies of hippotherapy have shown beneficial effects on body structures and functioning, unanswered questions remain.  For example, it is unclear which subgroups of children with CP would benefit the most, what "dose" or frequency of intervention is optimal.

An assessment of the evidence for hippotherapy by the Institute for Clinical Effectiveness and Health Policy (Pichon Riviere et al, 2006) concluded: "The efficacy of this therapy does not seem to have been sufficiently proven for any specific indication.  Its recreational role and impact on the quality of life of these patients have not been sufficiently analyzed."

Snider et al (2007) performed a systematic review of the literature on hippotherapy as an intervention for children with CP.  Retrieved articles were rated for methodological quality using Physiotherapy Evidence Database (PEDro) scoring to assess the internal validity of randomized trials and the Newcastle Ottawa Quality Assessment Scale to assess cohort studies.  Population, Intervention, Comparison, and Outcomes (PICO) questioning was used to identify questions of interest to clinicians for outcomes within the context of the International Classification of Functioning, Disability and Health.  Levels of evidence were then accorded each PICO question.  The authors reported that there is Level 2a evidence that hippotherapy has short-term positive effects on muscle symmetry in the trunk and hip and that hippotherapy is effective for improving muscle tone in children with CP when compared with regular therapy or time on a waiting list.  However, no studies addressed participation outcomes.  (Note: Level 2a evidence refers to 1 or more "fair" quality randomized controlled trials [PEDro = 4 to 5]; 6 to 8 is considered "good"; and 9 to 10 is considered "excellent"). An assessment of this systematic evidence review by the Centre for Reviews and Dissemination (2009) found that this systematic review was "poorly reported" and that, "given the potential for error or bias during the review process, these cautious conclusions may not be reliable." In particular, the authors did not report how many reviewers carried out study selection and data extraction. Conclusions are limited due to heterogeneity of the primary data, small sample sizes, and limited generalization of the patient samples.

Hamill et al (2007) examined the effects of a once-weekly, 10-week hippotherapy program for 3 children, aged 27 to 54 months, with CP.  Participants were rated as Level V on the Gross Motor Function Classification System.  The Sitting Dimension of the Gross Motor Function Measure was used to establish a baseline of sitting abilities, and was administered every 2 weeks during intervention.  The Sitting Assessment Scale and the Gross Motor Function Measure were administered before, after, and 4 weeks post-intervention.  Parental perceptions of the hippotherapy intervention were assessed using questionnaires.  None of the children made gains on any of the standardized outcome measures.  However, parental perceptions were very positive, with reported improvements in range of motion and head control.

Lechner et al (2007) examined the effect of hippotherapy on spasticity and on mental well-being of persons with spinal cord injury (SCI), and compared it with the effects of other interventions.  A volunteer sample of 12 people with spastic SCI (American Spinal Injury Association grade A or B) were included in this study; interventions consisted of hippotherapy, sitting astride a Bobath roll, and sitting on a stool with rocking seat.  Each session lasted 25 mins and was conducted twice-weekly for 4 weeks; the control condition was spasticity measurement without intervention.  Main outcome measures were clinical rating by a blinded examiner of movement-provoked muscle resistance, using the Ashworth Scale; self-rating of spasticity by subjects on a VAS; and mental well-being evaluated with the self-rated well-being scale Befindlichkeits-Skala of von Zerssen.  Assessments were performed immediately after intervention sessions (short-term effect); data from the assessments were analyzed 3 to 4 days after the sessions to calculate the long-term effect.  By analyzing the clinically rated spasticity, only the effect of hippotherapy reached significance compared with the control condition (without intervention); median differences in the Ashworth scores' sum before and after hippotherapy sessions ranged between -8.0 and +0.5.  There was a significant difference between the spasticity-reducing effect of hippotherapy and the other 2 interventions in self-rated spasticity by VAS; median differences of the VAS before and after hippotherapy sessions ranged between -4.6 and +0.05cm.  There were no long-term effects on spasticity.  Immediate improvements in the subjects' mental well-being were detected only after hippotherapy (p = 0.048).  The authors concluded that hippotherapy is more efficient than sitting astride a Bobath roll or on a rocking seat in reducing spasticity temporarily.  Hippotherapy had a positive short-term effect on subjects' mental well-being.  The major drawbacks of this study was its small sample size and that hippotherapy had no long-term effects on spasticity.

Sterba (2007) reported on a review of evidence for hippotherapy in CP, and concluded that hippotherapy and horseback riding are effective in improving gross motor skills.  However, a critical assessment of this evidence review by the Centre for Reviews and Dissemination (CRD, 2008) stated that "given the methodological limitations of both included studies and the review, these conclusions should be treated with caution."  The CRD found insufficient information about the study selection, data extraction and quality assessment process to determine whether these had been carried out independently by more than one reviewer, "thus the possibility of bias cannot be ruled out."  The CRD stated that methodological limitations evident in the included studies were: the inclusion of participants with developmental disabilities other than cerebral palsy, lack of statistical analysis, small sample sizes, use of outcome measures which have not been proven reliable or valid, and the possibility of bias.  The CRD found that "study quality and study design do not appear to have been considered sufficiently when interpreting the results."

McGibbon and colleagues (2009) investigated the immediate effects of 10 mins of hippotherapy, compared with 10 mins of barrel-sitting, on symmetry of adductor muscle activity during walking in children with CP (phase I; n = 47).  These researchers also investigated the long-term effects of 12 weekly sessions of hippotherapy on adductor activity, gross motor function, and self-concept (phase II; n = 6).  Main outcomes measures were: for phases I and II – adductor muscle activity measured by surface electromyography; for phase II – gross motor function and self-perception profiles.  In the phase I study, hippotherapy significantly improved adductor muscle asymmetry (p < 0.001; d = 1.32).  Effects of barrel-sitting were not significant (p > 0.05; d = 0.10).  In the phase II study, after 12 weeks of hippotherapy, testing in several functional domains showed improvements over baseline that were sustained for 12 weeks post-treatment.  The authors concluded that hippotherapy can improve adductor muscle symmetry during walking and can also improve other functional motor skills.

McGee and Reese (2009) examined the immediate effects of a hippotherapy session on temporal and spatial gait parameters in children with spastic CP.  Subjects comprised 9 children with a diagnosis of CP (6 girls and 3 boys, 7 to 18 years of age).  Data for temporal and spatial gait parameters were collected immediately before and after a hippotherapy session.  No statistically significant differences (p < 0.05) were noted in the post-ride temporal and spatial gait parameter values when compared with the pre-ride values.  The authors concluded that the findings of this study provides baseline data for future research and useful clinical information for physical therapists using hippotherapy as a treatment modality for children with spastic CP.

Schwesig et al (2009) tested the hypothesis that hippotherapy has both positive short- and long-term effects on gait and posture control of persons suffering from motoric disabilities.  A total of 22 children and adolescents aged 9.69 +/- 4.01 years (range of 9.69 +/- 4.01 years) with motoric dysfunctions were included in a prospective matched-control study.  In each participant, gait and posture control were investigated on 4 different occasions (O1 to O4) using the Interactive balance system and the portable gait analysis system RehaWatch.  The dates of gait and posture analysis were defined as follows: O1: immediately prior to first therapeutic riding session (TRS); O2: immediately after first TRS; O3: after the last day of an 8-week period of daily TRS; O4: 7 weeks later after a TRS-free interval.  The following parameters were slightly improved (adjusted significance level of p < 0.003) after 8 weeks of therapeutic riding: (O1 versus O 3):

1. walking distance (p = 0.009, eta(2) = 0.339);
2. pace frequency (p = 0.007, eta(2) = 0.358); and
3. walking speed (p = 0.006, eta(2) = 0.367), and
4. time of attachment (p = 0.007, eta(2) = 0.360). 

The only short-term effect observed was a significant decrease of the attachment phase (p = 0.002, eta(2) = 0.387).  Interestingly, gait symmetry remained unaffected.  Posturography (adjusted significance level of p < 0.01) at O1 versus O2 (short-term) showed a significant decrease of the performance of both the visual-nigrostriatal subsystem (p < 0.001) and the somato-sensory subsystem (p = 0.001).  At O1 versus O3 (long-term), the following parameters were sharply decreased:

1. postural stability (p = 0.011), and
2. somato-sensory performance (p = 0.011). 

The authors concluded that in the individuals investigated, an 8-week series of therapeutic riding did not improve posture control and had only a small positive effect on gait performance.  The reasons for these rather disappointing results could have been the low number of therapeutic riding sessions (0.5 sessions per week), and the relatively short duration (30 mins) of each session.  It remains to be seen, whether a higher density and longer duration of therapeutic riding sessions yields better results.

Oppenheim (2009) stated that there are no published studies specifically addressing complementary and alternative methods (CAM) in adults with CP.  However, national surveys of adults with chronic disabilities document that a majority of them use such treatments, that they are willing to pay out of pocket, if necessary, and that they believe that pursuing such treatment relieves pain, reduces stress and anxiety, and leads to improved feelings of fitness and well-being.  Individuals enjoy taking charge of their own health care decisions, and frequently feel more in control with these therapies than with more traditional methods.  In contrast to adults, there is some information on CAM in children with CP.  The author discussed some of the CAM used in children that may be carried over into adulthood, as well as the pitfalls for patients and conventional physicians as they try to sort out what might be helpful and what might be harmful in this arena.  Practitioners of both conventional and CAM therapies believe that exercise can be beneficial; accordingly, activities such as recreational sports, yoga, and hippotherapy may be continued from childhood into adulthood.  General treatments for stress and anxiety, through such activities as yoga and meditation, though not directed at CP per se, may be more popular for adults than children.  Research in this area should first identify what methods are being utilized and then subject these methods to well-designed outcome studies that take into account any associated risks.

Johnson (2009) analyzed evidence of the benefits of physical activity for youth with developmental disabilities.  A total of 3,263 citations was found.  Systematic reviews and articles about studies quantitatively examining the effects of physical activity in youth with developmental disabilities aged 0 to 20 years were included.  Only articles published in English in peer-reviewed journals were included; 3 systematic reviews and 14 studies were reviewed.  Strong evidence indicated that children and adolescents with developmental disabilities derive health benefits from participation in group exercise programs, treadmill training, or hippotherapy.  Lesser levels of evidence indicated that health benefits might be present for adapted skiing or aquatic programs.  Documented benefits of physical activity include improvements in aerobic capacity, improved gross motor function, and high levels of participant/parent satisfaction.  The author stated that further research studies are needed that are of greater scientific rigor including larger sample sizes, control groups, and stringent, replicable methodology.

More scientific evidence, especially controlled studies with outcome measures, is needed to ascertain the effectiveness of hippotherapy for the treatment of CP, multiple sclerosis (MS), and other motor dysfunction.

In a pilot study, Shurtleff and Engsberg (2010) evaluated the effectiveness of hippotherapy in improving head/trunk stability in children with CP.  The participants were 6 children with spastic diplegia and 6 children without disability.  Head and trunk stability was challenged by using a motorized barrel and measured by a video motion capture system before and after a 12-week intervention of 45-min of hippotherapy a week.  The variables measured were anterior-posterior (AP) translation of the head, and spine at 5 points and average AP head angles.  At pre-testing, children with CP demonstrated significant differences in AP translation and AP head rotation compared with children without disability.  Following hippotherapy, children with CP demonstrated significant reductions in head rotation and AP translation at C7, eye, and vertex.  At post-testing, translation at C7 did not differ significantly between children with CP and children without disability.  After hippotherapy intervention, children with CP reduced their AP head rotation and translation, suggesting that they had increased stability of the head and trunk in response to perturbations at the pelvis.  The findings suggested that hippotherapy might improve head and trunk stability in children with CP.  These preliminary findings need to validated by well-designed studies with more subjects and follow-up.

Bronson et al (2010) reviewed the evidence for hippotherapy as an intervention to improve balance in persons with MS.  Major electronic databases were searched for articles relating to hippotherapy, MS and balance.  Only full length articles published in peer reviewed journals that were written in English or translated into English were included.  Articles were assessed using a modified quality index that was used for descriptive purposes only and did not exclude any study from the review.  All studies examined in this review were either case-control or case-series.  Collectively, all 3 studies reported improvements in balance.  Pre-test and post-test Berg Balance Scale scores in 2 studies revealed that primary progressive MS demonstrated the greatest amount of change after hippotherapy compared to other subtypes of MS.  The authors concluded that hippotherapy has a positive effect on balance in persons with MS and has an added benefit of enhancing quality of life.  They stated that data are limited and further research will lead to a greater knowledge base and has the potential to increase accessibility for hippotherapy to be used as a rehabilitation modality.

Munoz-Lasa et al (2011) examined the effect of therapeutic horseback riding (THR) on the balance and gait of ambulatory patients with MS.  A total of 27 subjects were included in the study.  Patients were divided into 2 groups:

1. 12 underwent THR, and
2. 15 traditional physiotherapy (for both groups, 2 series of 10 weekly sessions were performed). 

Before and after the study period, the following outcome measures were applied: Extended Disability Status Scale (EDSS), Barthel Index, Tinetti Performance-Oriented Mobility Assessment (POMA).  In addition, patients of the THR group underwent a gait analysis to assess spatiotemporal gait parameters and ground reaction forces.  The THR group showed a significant improvement in POMA scores (p < 0.005) and 2 gait parameters: stride time (p < 0.04) and ground reaction forces (p < 0.01).  No statistically significant change was found in the control group.  The authors concluded that the results of the study showed that THR can improve balance and gait of ambulatory patients with MS.  Moreover, they stated that these findings are preliminary, but promising and in line with the recent literature.

In a meta-analysis, Zadnikar and Kastrin (2011) examined the effects of hippotherapy and thTHR on postural control or balance in children with CP.  To synthesize previous research findings, a systematic review and meta-analysis were undertaken.  Relevant studies were identified by systematic searches of multiple online databases from the inception of the database through to May 2010.  Studies were included if they fulfilled the following criteria:

• quantitative study design,
• investigation of the effect of hippotherapy or THR on postural control or balance, and
• the study group comprised children and adults with CP. 

The selected articles were rated for methodological quality.  The treatment effect was coded as a dichotomous outcome (positive effect or no effect) and quantified by odds ratio (OR).  The pooled treatment effect was calculated using a random-effects model.  Meta-regression of the effect size was performed against study co-variates, including study size, publication date, and methodological quality score.  From 77 identified studies, 10 met the inclusion criteria.  Two were excluded because they did not include a comparison group.  Therapy was found to be effective in 76 out of 84 children with CP included in the intervention groups.  The comparison groups comprised 89 children: 50 non-disabled and 39 with CP.  A positive effect was shown in 21 of the children with CP in the comparison group regardless of the activity undertaken (i.e., physiotherapy, occupational therapy, sitting on a barrel or in an artificial saddle).  The pooled effect size estimate was positive (OR 25.41, 95 % confidence interval [CI]: 4.35 to 148.53), demonstrating a statistically significant effectiveness of hippotherapy or THR in children with CP (p < 0.001).  Meta-regression of study characteristics revealed no study-specific factors.  The authors concluded that the 8 studies found that postural control and balance were improved during hippotherapy and THR.  They stated that although the generalization of their findings may be restricted by the relatively small sample size, the results demonstrated that riding therapy is indicated to improve postural control and balance in children with CP.

Whalen and Case-Smith (2012) examined the effectiveness of hippotherapy or THR on motor outcomes in children with CP.  Databases were searched for clinical trials of hippotherapy or THR for children with CP.  A total of 9 articles were included in this review.  Although the current level of evidence is weak, this synthesis found that children with spastic CP, Gross Motor Function Classification System (GMFCS) levels I to III, aged 4 years and above are likely to have significant improvements on gross motor function as a result of hippotherapy and THR.  Evidence indicated that 45-min sessions, administered once-weekly for 8 for 10 weeks, resulted in significant effects.  The authors concluded that the current literature on hippotherapy and THR is limited.  They stated that large randomized controlled trials (RCTs) using specified protocols are needed to more conclusively determine the effects on children with CP.  

Tseng et al (2013) evaluated the literature on the effectiveness of equine-assisted activities and therapies (EAAT) on gross motor outcomes representing the ICF component of body functions and activity in children with CP.  These investigators conducted a systematic review and meta-analysis of RCTs and observational studies of hippotherapy (HPOT) and THR for children with spastic CP.  Gross motor outcomes, assessed via muscle activity and muscle tone, gait, posture and GMFM were evaluated.  A total of 5 THR studies and 9 HPOT studies were included.  This meta-analysis indicated that short-term HPOT (total riding time 8 to 10 mins) significantly reduced asymmetrical activity of the hip adductor muscles.  HPOT could improve postural control in children with spastic CP, GMFCS level of less than 5.  However, the evidence did not show a statistically significant effect on GMFM after long-term HPOT or THR (total riding time, 8 to 22 hrs) in children with spastic CP.  The authors concluded that this systematic review found insufficient evidence to support the claim that long-term THR or HPOT provides a significant benefit to children with spastic CP.  They found no statistically significant evidence of either therapeutic effect or maintenance effects on the gross motor activity status in CP children.

Hippotherapy has also been used in the treatment of patients with autism.  However, there is a lack of reliable scientific evidence regarding its effectiveness.

In a pilot study, Manikowska (2013) examined the effect of hippotherapy on spatio-temporal parameters of gait in children with CP.  A total of 16 ambulatory CP children (GMFCS Level I to III; female: 10, male: 6; age of 5.7 to 17.5 years) qualified for hippotherapy were investigated.  Basic spatio-temporal parameters of gait, including walking speed, cadence, step length, stride length and the left-right symmetry, were collected using a 3-dimensional accelerometer device (DynaPort MiniMod) before and immediately after a hippotherapy session.  The Wilcoxon test was used to verify the differences between pre- and post-session results.  Changes of walking speed were statistically significant.  With the exception of step length, all spatio-temporal parameters improved, i.e., were closer to the respective reference ranges after the session.  However, these changes were not statistically significant.  The authors concluded that 1 session of hippotherapy may have a significant effect on the spatio-temporal parameters of gait in children with CP.  The findings of this small, pilot study need to be validated by well-designed studies.

In a single-blind RCT, Beinotti et al (2013) examined the impact of horseback riding therapy (HBRT) on the quality of life (QOL) of individuals with hemiparesis after stroke.  A total of 24 post-stroke patients were assigned to the experimental (n = 12) and control (n = 12) groups.  The control group participated in a conventional physiotherapy program, whereas the experimental group participated in physiotherapy plus HBRT sessions for 16 weeks.  The patients were evaluated by means of the SF-36.  Data analysis was applied through the use of descriptive and inferential statistics, with a 5 % level of significance.  Significant improvement was observed in the total score of the SF-36 in the experimental group when compared with the control group.  The combination of conventional physiotherapy and HBRT was associated with improvements in functional capacity (p = 0.02), physical aspects (p = 0.001), and mental health (p = 0.04) of the stroke patients.  The authors concluded that supplementation of conventional physiotherapy with HBRT, applied in different contexts, may yield positive QOL outcomes for people with stroke.  These investigators recommended that further studies be carried out to clarify the benefits of HBRT applied singly.

Homnick et al (2013) examined the effect of an 8-week therapeutic riding (TR) program on measures of balance and QOL in community-dwelling older adults with established balance deficits.  The study was conducted at a Professional Association of Therapeutic Horsemanship (PATH) International Premier riding center.  Subjects comprised 9 adults (5 females, 4 males) with a mean age of 76.4 years (range of 71 to 83).  Treatment included an 8-week observation period followed by an 8-week TR program consisting of 1 hour/week of supervised horseback riding and an 8-week follow-up period.  Subjects received balance testing at weeks 0, 8, 16, and 24 using the Fullerton Advanced Balance Scale (FABS), and QOL was measured at weeks 8 and 16 using the Rand SF-36 QOL measure.  Outcome measures were change in the FABS and Rand SF-36.  There was no significant difference in balance scores between the start and end of the observation period.  There was a significant improvement in the balance score and perception of general health from the start to the end of the intervention period, and no significant difference between the end of the intervention and the end of study, suggesting that improvements may have been sustained.  The authors concluded that TR is a safe activity for older adults with mild-to-moderate balance deficits and leads to both improvements in balance and QOL.  Moreover, they stated that longer and larger studies are needed to ascertain the benefit of equine-assisted activities on improvements in balance and reduction in fall risk.

Dezutti (2013) noted that patients with eating disorders may have the most complex inter-disciplinary treatment plans of any mental illness.  Nurses need innovative evidence-based treatment interventions to assist their patients with eating disorders on their road to recovery.  Although much has been written about equine-assisted psychotherapy (EAP) and equine-facilitated psychotherapy, the literature has not described a detailed session that can help nurses understand how this experiential treatment works and the impact it can have on the patient.

In a pilot study, Cerulli et al (2014) evaluated the physiologic and psychological effects of an equine-assisted therapy (EAT) protocol in breast cancer survivors.  A total of 20 women (mean age of 45.61 ± 2.71 years) whose breast cancer treatment had concluded at least 6 months previously underwent a screening protocol to certify their eligibility to participate in non-competitive sports.  The patients were randomly assigned to an intervention group (n = 10) or a control group (n = 10).  Intervention patients participated in a 16-week EAT protocol consisting of 2 hours of activity per week.  All patients were tested before and after the intervention for maximal oxygen consumption (VO2max), fat mass percentage, total body water percentage, strength of principal muscular groups (measured on 5 weight-lifting machines [leg press, leg extension, leg curl, shoulder press, vertical traction]), and quality of life using the Functional Assessment of Chronic Illness Therapy-Fatigue questionnaire (FACIT-F).  After intervention, the intervention group showed an improvement in VO2max (28.29 %; p < 0.001), a decrease in fat mass percentage (change, -7.73 %; p < 0.002), an increase in total body water percentage (6.90 %; p = 0.027), and an increase in strength (leg press, 17.75 % [p = 0.018]; leg extension, 21.55 % [p = 0.005]; leg curl, 26.04 % [p < 0.001]; shoulder press, 49.72 % [p = 0.003]; vertical traction, 19.27 % [p = 0.002]).  Furthermore, the increase in the 3 FACIT-F scores (FACIT-F trial outcome: 9.29 % [p = 0.010]; Functional Assessment of Cancer Therapy-General total score, 14.80 % [p = 0.022]; and FACIT-F total score, 11.48 % [p =0.004]) showed an increase in quality of life.  No significant changes for any variable were found for the control group.  The authors concluded that EAT had positive effects on both physiologic and psychological measures, enhancing quality of life of breast cancer survivors.  They stated that these results suggested a new method for rehabilitation intervention strategies after cancer in a non-medical environment.  These findings from a pilot study need to be validated by well-designed studies.

Nurenberg et al (2015) stated that animal-assisted therapy (AAT), most frequently used with dogs, is being used increasingly as an adjunctive alternative treatment for psychiatric patients.  Animal-assisted therapy with larger animals, such as horses, may have unique benefits.  In this randomized controlled study, equine and canine forms of AAT were compared with standard treatments for hospitalized psychiatric patients to determine AAT effects on violent behavior and related measures.  The study included 90 patients with recent in-hospital violent behavior or highly regressed behavior.  Hospitalization at the 500-bed state psychiatric hospital was 2 months or longer (mean of 5.4 years).  Participants were randomly selected to receive 10 weekly group therapy sessions of standardized EAP, canine-assisted psychotherapy (CAP), enhanced social skills psychotherapy, or regular hospital care.  Participants' mean age was 44, 37 % were female, 76 % had diagnoses of schizophrenia or schizoaffective disorder, and 56 % had been committed involuntarily for civil or forensic reasons.  Violence-related incident reports filed by staff in the 3 months after study intake were compared with reports 2 months pre-intake.  Interventions were well-tolerated.  Analyses revealed an intervention group effect (F = 3.00, df = 3 and 86, p = 0.035); post-hoc tests showed specific benefits of EAP (p < 0.05).  Similar AAT effects were found for the incidence of 1:1 clinical observation (F = 2.70, df = 3 and 86, p = 0.051); post-hoc tests suggested benefits of CAP (p = 0.058) as well as EAP (p = 0.082).  Co-variance analyses indicated that staff can predict which patients are likely to benefit from EAP (p = 0.01).  The authors concluded that AAT, and perhaps EAP uniquely, may be an effective therapeutic modality for long-term psychiatric patients at risk of violence.  These preliminary findings need to be validated by well-designed studies with longer follow-up.

Del Rosario-Montejo et al (2015) stated that equine therapy is used to treat patients susceptible to psychomotor delays.  These researchers examined development of gross motor function compared to other psychomotor skills in patients undergoing this therapy, and analyzed how this improvement affects general health status and quality of life.  The study included 11 children with delayed psychomotor development (aged 8.82 ± 3.89; 6 boys, 5 girls).  The main study variables were gross motor function (GMFM-88) and perceived quality of life (Pediatric Quality of Life Inventory, PedsQL). Three measurements were performed:

1. before and after a period of inactivity,
2. 2 months after the second measurement, and
3. following completion of a sustained period of therapy.

These investigators observed significant differences in overall results on the GMFM-88 between the initial and final tests and between the intermediate and final tests.  Regarding the PedsQL quality of life scale, no statistically significant results were recorded.  The authors concluded that noticeable changes in motor control were recorded throughout the course of the intervention, which suggested that equine therapy may be appropriate treatment in cases of delayed psychomotor development.  These preliminary findings need to be validated by well-designed studies.

Cerebral Palsy

Dewar et al (2015) evaluated the efficacy and effectiveness of exercise interventions that may improve postural control in children with CP.  These investigators performed a systematic review using American Academy of Cerebral Palsy and Developmental Medicine (AACPDM) and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology.  Six databases were searched using the following keywords: ('cerebral palsy' OR 'brain injury'); AND ('postur*' OR 'balance' OR 'postural balance' [MeSH]); AND ('intervention' OR 'therapy' OR 'exercise' OR 'treatment').  Articles were evaluated based on their level of evidence and conduct.  Searches yielded 45 studies reporting 13 exercise interventions with postural control outcomes for children with CP.  Five interventions were supported by a moderate level of evidence: gross motor task training, hippotherapy, treadmill training with no body weight support (no-BWS), trunk-targeted training, and reactive balance training.  Six of the interventions had weak or conflicting evidence: functional electrical stimulation (FES), hippotherapy simulators, neurodevelopmental therapy (NDT), treadmill training with body weight support, virtual reality, and visual biofeedback.  Progressive resistance exercise was an ineffective intervention, and upper limb interventions lacked high-level evidence.  The authors concluded that the use of exercise-based treatments to improve postural control in children with CP has increased significantly in the last decade.  Improved study design provided more clarity regarding broad treatment efficacy.  Moreover, they stated that research is needed to establish links between postural control impairments, treatment options, and outcome measures.  Low-burden, low-cost, child-engaging, and mainstream interventions also need to be explored.

An UpToDate review on "Management and prognosis of cerebral palsy" (Miller, 2015) states that "Not recommended – In a comprehensive review, physical therapy approaches that were not recommended because of lack of efficacy include neurodevelopmental therapy (NDT) and sensory integration therapy (SIT).  NDT is the direct passive handling of limbs by the therapist, with guidance intended to normalize the patterns of movement.  It is not recommended because of the availability of more effective alternatives.  Any gains in range of motion that are achieved during an NDT session do not carry over.  Better functional gains are achieved with motor-learning approaches, and BTX is more effective than NDT for managing spasticity.  Similarly, systematic reviews conclude that SIT is not effective and should be replaced by effective alternatives such as those listed above.  Many other activities' interventions are supported only by low-quality or inconclusive evidence, precluding a recommendation for or against their use.  Among these, early intervention for motor outcomes is a promising approach because of supporting evidence in populations without CP.  Interventions with weak evidence are animal-assisted therapy, assistive technology, hippotherapy (therapeutic horse-riding) …. ".

Viruega and colleagues (2019) stated that there is still a lack of studies focused on trunk neurorehabilitation.  Accordingly, it is unclear which therapeutic modalities are the most effective in improving static/dynamic balance after brain damage.  These researchers designed a pilot study on hippotherapy to assess its short- and mid-term effect on dynamic postural balance in patients with moderate-to-severe sensorimotor impairment secondary to CP.  A total of 5 patients aged 15.4 ± 6.1 years old were recruited.  All of them had moderate-to-severe alterations of the muscle tone with associated postural balance impairment.  Standing and walking were also impaired; 10 mins horse riding simulator followed by 20 mins hippotherapy session were conducted during 5 session days separated by 1 week each.  These researchers analyzed the displacement of the Center of Pressure (COP) on the sitting surface of the simulator's saddle by means of a customized pressure pad.  They measured the general behavior of the COP displacement as well as the postural adjustments when pace changed from walk to trot to walk during the sessions and among sessions.  Statistical analysis revealed an improved postural control both by the end of the session and from session 1 to session 5.  The authors concluded that the findings of this study suggested that hippotherapy might support regularization of postural control in a long-term neurorehabilitation context.

The authors stated that this pilot study was designed to evaluate the effects of an experimental protocol of horse-riding simulation combined with hippotherapy on postural balance efficacy in patients with sensorimotor impairment secondary to CP.  The cohort was small (n = 5) and rather heterogeneous and a larger cohort study has to confirm and fine-tune these encouraging preliminary results.  Furthermore, it could be relevant to couple the kinetic measures with kinematics and/or electromyographic (EMG) data in order to have a more complete picture of the relationship between the central drive and the effectors.  Also, a long-term follow-up on the residual changes after the termination of the hippotherapy cycle has to be performed in future studies.

De Guindos-Sanchez and colleagues (2020) noted that CP is a permanent disorder of the posture and movement, which can result in impairments of gross motor function, among others.  Hippotherapy (HPT) is an emerging intervention to promote motor recovery in patients with neurological disorders, providing a smooth, precise, rhythmic, and repetitive pattern of movement to the patient.  In a systematic review and meta-analysis of RCTs, these investigators examined the effectiveness of HPT interventions on gross motor function in subjects with CP.  The following data-bases were searched in May 2019: PubMed, Scopus, Embase, and Web of Science.  The methodological quality of the RCTs was evaluated using the Physiotherapy Evidence Database (PEDro) scale.  A total of 10 studies were examined in this review, involving 452 subjects.  Favorable effects were obtained on the gross motor function (Gross Motor Function Measure-66, SMD = 0.81, 95 % CI: 0.47 to 1.15, Gross Motor Function Measure-88 dimension A SMD = 0.64, 95 % CI: 0.30 to 0.97, dimension B SMD = 0.42, 95 % CI: 0.09 to 0.75, and dimension E SMD = 0.40, 95 % CI: 0.06 to 0.73).  The results obtained in the present review showed the potential benefit of HPT intervention in improving gross motor function in children with CP.  These researchers stated that it will be necessary to perform more RCTs with larger sample sizes and specified protocols.

The authors stated that this systematic review had several drawbacks.  Potential useful articles that were indexed in other scientific data-bases could not be included.  Furthermore, the lack of long-term follow-up and the heterogeneity of the protocols suggested the need to unify the HPT intervention programs, specifically, in subjects with CP.  Moreover, despite examining the same outcomes between the different studies included in the review, the statistical comparison was not always possible due to studies used different scales and measuring instruments to evaluate the clinical differences.  Therefore, only 2 studies were included in the meta-analysis; thus, the results obtained should be taken with caution since only a limited number of studies was analyzed.

Behavioral and Psychiatric Disorders

Anestis et al (2014) stated that equine-related treatments (ERT) for mental disorders are becoming increasingly popular for a variety of diagnoses; however, they have been subjected only to limited systematic investigation.  These researchers examined the quality of and results from peer-reviewed research on ERT for mental disorders and related outcomes.  Peer-reviewed studies (n = 14) examining treatments for mental disorders or closely related outcomes were identified from databases and article reference sections.  All studies were compromised by a substantial number of threats to validity, calling into question the meaning and clinical significance of their findings.  Additionally, studies failed to provide consistent evidence that ERT is superior to the mere passage of time in the treatment of any mental disorder.  The authors concluded that the current evidence base does not justify the marketing and utilization of ERT for mental disorders.  Such services should not be offered to the public unless and until well-designed studies provide evidence that justify different conclusions.

Multiple Sclerosis

In a single-subject experimental design study (n = 11), Hammer and associates (2005) examined whether therapeutic riding (TR, Sweden), also known as hippotherapy (HT, United States) may affect balance, gait, spasticity, functional strength, coordination, pain, self-rated level of muscle tension (SRLMT), activities of daily living (ADL), and health-related quality of life in patients with MS.  The intervention comprised 10 weekly TR/HT sessions of 30 mins each.  The subjects were measured a maximum of 13 times.  Physical tests were: the Berg balance scale, taking a figure of 8, the timed up and go test, 10-m walking, the modified Ashworth scale, the Index of Muscle Function, the Birgitta Lindmark motor assessment, part B, and individual measurements.  Self-rated measures were: the visual analog scale (VAS) for pain, a scale for SRLMT, the Patient-Specific Functional Scale for ADL, and the Medical Outcomes Study 36-item Short-Form health survey (SF-36).  Data were analyzed visually, semi-statistically and considering clinical significance.  Results showed improvement for 10 subjects in one or more of the variables, particularly balance, and some improvements were also seen in pain, muscle tension, and ADL.  Changes in SF-36 were mostly positive, with an improvement in Role-Emotional seen in 8 patients.  These investigators concluded that balance and Role-Emotional were the variables most often improved, but TR/HT appeared to benefit the subjects differently.

In a case-series study, Lindroth et al (2015) examined if there were observable changes in sensory processing for postural control in individuals with MS following physical therapy using HPOT or changes in balance and functional gait.  This pre-test non-randomized design study, with follow-up assessment at 6 weeks, included 2 females and 1 male (age range of 37 to 60 years) with diagnoses of relapse-remitting or progressive MS.  The intervention consisted of twelve 40-min physical therapy sessions which included HPOT twice-weekly for 6 weeks.  Sensory organization and balance were assessed by the Sensory Organization Test (SOT) and Berg Balance Scale (BBS).  Gait was assessed using the Functional Gait Assessment (FGA).  Following the intervention period, all 3 participants showed improvements in SOT (range of 1 to 8 points), BBS (range of 2 to 6 points), and FGA (average of 4 points) scores.  These improvements were maintained or continued to improve at follow-up assessment; 2 of the 3 participants no longer over-relied on vision and/or somatosensory information as the primary sensory input for postural control, suggesting improved use of sensory information for balance.  The authors concluded that these findings indicated that HPOT may be a beneficial physical therapy treatment strategy to improve balance, functional gait, and enhance how some individuals with MS process sensory cues for postural control.  Moreover, they stated that randomized clinical trials are needed to validate results of this study.

Vermohlen and associates (2018) examined the effect of hippotherapy plus standard care versus standard care alone in MS patients.  A total of 70 adults with MS were recruited in 5 German centers and randomly allocated to the intervention group (12 weeks of hippotherapy) or the control group.  Primary outcome was the change in the Berg Balance Scale (BBS) after 12 weeks, and further outcome measures included fatigue, pain, QOL, and spasticity.  Co-variance analysis of the primary end-point resulted in a mean difference in BBS change of 2.33 (95 % CI: 0.03 to 4.63, p = 0.047) between intervention (n = 32) and control (n = 38) groups.  Benefit on BBS was largest for the subgroup with an EDSS of greater than or equal to 5 (5.1, p = 0.001).  Fatigue (-6.8, p = 0.02) and spasticity (-0.9, p = 0.03) improved in the intervention group.  The mean difference in change between groups was 12.0 (p < 0.001) in physical health score and 14.4 (p < 0.001) in mental health score of Multiple Sclerosis QOL-54 (MSQOL-54).  The authors concluded that hippotherapy plus standard care, while below the threshold of a minimal clinically important difference, significantly improved balance and also fatigue, spasticity, and QOL in MS patients.

Munoz-Lasa and colleagues (2019) stated that hippotherapy is a promising method in the physical treatment of MS.  These researchers carried out a comparative, open, clinical pre-post study into hippotherapy intervention (non-randomized) during a 6-month period in patients with MS (n = 6) and a h control group (n = 4).  A statistically significant improvement was observed in the therapy group in: spasticity pre-post measured by the modified Ashworth scale (p = 0.01).  Statistically significant improvement in fatigue impact (p < 0.0001) measured with fatigue impact scale (FIS); in general, perception of heath outcome in urinary QOL scale King's Health Questionnaire (KHQ) (p = 0.033), and in subscales 2, 3 and 4 of MSQOL-54 (p = 0.011).  Control group showed no improvement in any scale.  The authors concluded that the findings of this study reinforced current literature that supports hippotherapy as an adequate intervention for MS patients.  Moreover, they stated that further studies with more participants, control groups and blinded research would be logical steps for future research in this field.

Anxiety and Post-Traumatic Stress Disorder

Earles and colleagues (2015) examined the effectiveness of the Equine Partnering Naturally(©) approach to equine-assisted therapy for treating anxiety and post-traumatic stress disorder (PTSD) symptoms.  Participants were 16 volunteers who had experienced a Criterion A traumatic event, such as a rape or serious accident, and had current PTSD symptoms above 31 on the PTSD Checklist (PCL-S; Weathers, Litz, Herman, Huska, and Keane).  Participants engaged in tasks with horses for 6 weekly 2-hour sessions.  Immediately following the final session, participants reported significantly reduced post-traumatic stress symptoms, d = 1.21, less severe emotional responses to trauma, d = 0.60, less generalized anxiety, d = 1.01, and fewer symptoms of depression, d = 0.54.  As well, participants significantly increased mindfulness strategies, d = 1.28, and decreased alcohol use, d = 0.58.  There was no significant effect of the treatment on physical health, proactive coping, self-efficacy, social support, or life satisfaction.  Thus, the authors found evidence that the Equine Partnering Naturally(©) approach to equine-assisted therapy may be an effective treatment for anxiety and post-traumatic stress symptoms.  They stated that future research should include larger groups, random assignment, and longer term follow-up.

Shelef and colleagues (2019) noted that EAT that includes THR, grooming, horsemanship and ground level work with horses, has been studied as treatment for children with special needs and/or ASD.  Preliminary evidence indicated that EAT is also effective for improving self-efficacy and self-esteem in adults with psychiatric disorders.  Empowerment, bonding and building trust with the horses, may promote functioning of patients struggling with PTSD. These researchers performed a prospective, open, case-series, pilot study to examine the effect of EAT on patients with PTSD in terms of symptoms and functioning in work, family and social interaction.  Patients with PTSD received EAT once-weekly for 3 consecutive hours for 6 months.  The Short Post Traumatic Stress Disorder Rating Interview (SPRINT) and the Sheehan Disability Scale (SDS) were assessed at baseline, the SDS after 1 and 6 months, and the SPRINT after 6 months; and 13 of 23 subjects completed the study; 10 subjects withdrew from the study for various reasons including discomfort from horses.  Total SPRINT scores showed a statistically significant improvement in PTSD symptoms (baseline versus 6 months: 24.38 ± 6.4 versus 21.54 ± 7.94 points; p < 0.05).  SPRINT scores indicated improvement in the ability to work and perform daily tasks (p < 0.05).  A statistically significant improvement in the total SDS score was revealed following 1 month (p < 0.03) and after 6 months (p < 0.02) of EAT.  There was also a significant decline in the days of inefficiency (baseline versus 6 months: 4.15 ± 2.73 versus 1.88 ± 2.18 days per week, p < 0.02).  The authors concluded that the findings of this preliminary, open, case-series, pilot study suggested that EAT may be a beneficial treatment for patients suffering from PTSD.  The study demonstrated improved ability to work and perform daily tasks and reduction in the number of days of inefficiency.  These researchers stated that further large-scale, long-term studies are needed to substantiate their observation.

Kovacs and colleagues (2020) stated that the growing field of EAP, a subfield of animal-assisted psychotherapy (AAP), needs theoretically-based clinical studies.  In a systematic review, these investigators examined the existing clinical studies in adult populations on psychodynamic psychotherapy combined with EAP.  An electronic data-base search was divided in 2 studies to identify publications on EAP combined with psychodynamic psychotherapy; and EAP combined to personality problems and traumatization in order to compile studies by population, intervention, outcome and therapeutic assets.  Study 1 revealed no relevant clinical studies on EAP with a psychodynamic background with an adult population.  Study 2 revealed 12 publications to review predominantly addressing veterans with PTSD.  The methodological limitations of most of the studies restrained the overall findings on outcome.  However, overall positive effects for EAP, specifically on its experiential features and on finding inter-personal trust for patients, can be discerned.  The authors concluded that there is an apparent need for clinical studies meeting methodological standards on psychodynamic underpinned EAP methodologies in adults with intertwined personality problems and traumatization.

To establish EAP as a feasible treatment modality for vulnerable patients, like chronic early trauma (CET) and to further the field of AAP and EAP, these researchers suggest 5 future directions.  First, as already mentioned, establishing a clear outline of procedures of an integrated equine-assisted psychodynamic orientation in clinical studies.  A proposed outline should avoid a protocol-based approach but should preferably enhance the personal approach to psychotherapy.  Secondl, to conduct empirical clinical studies comparing classical psychodynamic orientated psychotherapy to an integrated equine-assisted psychodynamic psychotherapy for CET patients.  Third, focusing on the mechanism of change from a psychodynamic- and attachment-based view like establishing epistemic trust, embodied affect- and stress regulation, inter-and intra-personal deficits such as self-efficacy and resilience in traumatized patients as several reviewed studies elicited.  Fourth, next to quantitative studies, qualitative studies, whether or not as part of a mixed model, could draw insight in mechanisms of change from a patient perspective.  Fifth, these investigators recommend to gain insight in the personality characteristics of patients who choose EAP allowing for a more transdiagnostic approach of co-morbid symptomatology in order to examine "what works for whom".

Attention Deficit and/or Hyperactivity Disorder

Lee and colleagues (2015) examined the effects of hippotherapy on brain function and levels of blood-derived neurotrophic factor (BDNF) in children with attention deficit and/or hyperactivity disorder (ADHD).  The hippotherapy group (HRG) included 20 children with ADHD and the control group (CG) included 19 children.  All participants' physical fitness, functional magnetic resonance imaging (fMRI) brain scans, and blood BDNF levels were measured at baseline and after 32 weeks of participating in hippotherapy.  After 32 weeks of participating in hippotherapy, the body fat of the HRG was significantly decreased (-1.12 ± 4.20 %) and the body fat of the CG was increased (2.38 ± 6.35 %) (p = 0.049).  There was no significant difference of physical fitness in both groups (p > 0.05).  Although there was a higher decrease in the activated insular area in the HRG (-1.59 ± 0.99) than in the CG (-1.14 ± 1.41), there was no significant difference between the 2  groups (p > 0.05).  Furthermore, there was a higher increase in the activated cerebellum area in the HRG (1.97 ± 1.45) than in the CG (1.92 ± 1.81).  However, there was no significant difference between the 2 groups (p > 0.05); BDNF levels showed an increased tendency in the HRG (166.29 ± 277.52 pg) compared to the CG (21.13 ± 686.33 pg); otherwise, there was not any significant difference in these blood levels between the 2 groups (p > 0.05).  It can be assumed that big individual differences in the level of ADHD in the study participants might not cause any significant results, although there might be positive changes in the brain function of children with ADHD.  The authors concluded that the findings of this study suggested that hippotherapy training would need to be modified and developed to increase the effectiveness of hippotherapy in children with ADHD.

In a 12-week, prospective, open-label trial, Jang and associates (2015) examined the clinical effects of equine-assisted activities and therapy (EAA/T) for treating ADHD in children aged 6 to 13 years.  This study entailed 24 sessions of EAA/T with 20 participants (19 boys and 1 girl) completed 12 weeks of EAA/T.  Various clinical tests were administered at baseline and after EAA/T.  Assessments included the investigator-administered ADHD-Rating Scale (ARS-I), Clinical Global Impressions-Severity Scale (CGI-S), Clinical Global Impressions-Improvement Scale (CGI-I), Gordon Diagnostic System, Korea-Child Behavior Checklist (K-CBCL), Self-Esteem Scale, second edition of the Bruininks-Oseretsky test of motor proficiency (BOT-2), and quantitative electroencephalography.  The primary efficacy measure was the response rate.  The response rate was 90 % based on a 30 % or greater decline in the ARS-I score or 85 % based on CGI-I scores of 1 or 2.  The mean ± standard deviation ARS-I score decreased from 33.65 ± 6.42 at baseline to 16.80 ± 6.86 after 12 weeks of EAA/T (p < 0.001, paired t-test).  It was reported that EAA/T also resulted in significant improvement in the social problems subscale of the K-CBCL and in the manual dexterity, bilateral coordination, and total motor composite subscales of the BOT-2.  The theta/beta ratio on electroencephalography was decreased significantly at the Pz electrode after 12 weeks of EAA/T.  The authors concluded that this was the first study demonstrating that EAA/T is effective for improving core ADHD symptoms.  They stated that on the basis of these results, EAA/T could be a viable treatment strategy as a part of a multi-modal therapy for children with ADHD.  The main drawbacks of this study were its small sample size (n = 20), short-term follow-up (12 weeks) and its open-label design.  These preliminary findings need to be validated by well-designed studies.

Furthermore, an UpToDate review on "Attention deficit hyperactivity disorder in children and adolescents: Overview of treatment and prognosis" (Krull, 2015) does not mention hippotherapy as a therapeutic option.

In a pilot study, Yoo and colleagues (2016) examined the effects of EAA/T on participants with ADHD by comparing resting-state fMRI (rs-fMRI) signals and their clinical correlates.  A total of 10 subjects with ADHD participated in a 12-week EAA/T program without any medication; 2 rs-fMRIs were acquired for all subjects before and after EAA/T.  For estimating therapeutic effect, the regional homogeneity (ReHo) method was applied to capture the changes in the regional synchronization of functional signals.  After the EAA/T program, clear symptom improvement was found even without medication.  Surface-based pair-wise comparisons revealed that ReHo in the right precuneus and right pars orbitalis clusters had significantly diminished after the program.  Reduced ReHo in the right precuneus cluster was positively correlated with changes in the scores on DuPaul's ADHD Rating Scale-Korean version.  The authors concluded that these findings indicated that EAA/T is associated with short-range functional connectivity in the regions related to the default mode network and the behavioral inhibition system, which are associated with symptom improvement.  They stated that for equine therapy to be accepted as an adjunct therapeutic option for ADHD, additional studies with larger samples, controlled designs, and purposeful fMRI sessions are needed.

This pilot study had several drawbacks:

1. the study included only a subset of ADHD subjects who finished the 12-weeks of EAA/T.
2. Comparison with the typically developing children would be needed in the future; these researchers only analyzed resting-state data, and thus, the direct effects of EAA/T on task-related performance such as attention, emotion, and cognition could not be estimated. Investigating those effects requires task-specific fMRI designs for each domain, and
3. long-term effects could not be examined from a single 12-week EAA/T session.

Lee and colleagues (2017) examined the effect of hippotherapy and electroencephalography (EEG) neurofeedback on brain function and blood BDNF level in children with ADHD.  A total of 16 children with ADHD participated in this study and were randomly divided into 2 groups:

1. a 1-time hippotherapy group (W1G, n = 8), and
2. a 2-time hippotherapy group (W2G, n = 8).  

All the participants attended 8 weeks of hippotherapy program in the primary training, and then 7 children with ADHD attended 8 weeks of hippotherapy program combined with neurofeedback training in the secondary training.  Blood BDNF levels were measured, and fMRI was performed.  The EEG neurofeedback training program was used to train and measure psychological factors.  The combined effect of hippotherapy and neurofeedback on BDNF level showed a decreased tendency in W1G (pre-training, 1,766.03 ± 362.54 pg/ml; post-training, 1,630.65 ± 276.70 pg/ml).  However, the BDNF level of W2G showed an increased tendency (pre-training, 1,968.28 ± 429.08 pg/ml; post-training, 1,976.28 ± 425.35 pg/ml).  Moreover, combined training showed a significant group x repetition interaction in W1G (pre-training, 1,436.57 ± 368.76 pg/ml; post-training, 1,525.23 ± 346.22 pg/ml; F = 3.870, p = 0.039); fMRI results showed that the left thalamus activity in both groups had a decreased tendency and a significantly lower change in W2G than in W1G (p < 0.05).  The authors concluded that the findings of this study suggested that hippotherapy combined with various psychological interventions would be useful for improving brain function in children with ADHD. Moreover, they recommended that future studies consider consistency of ADHD level and unified exercise intensity application for better understanding of the effects of hippotherapy and neurofeedback training on children with ADHD.

This study had 2 major drawbacks:

1. the ADHD level of each subject might be inconsistent, which might have negatively affected the study results, and 
2. the progress of each subject in hippotherapy differed because of the different levels of learning ability.  

This might have caused a variation in exercise intensity, although the study set the same exercise intensity.

Oh and co-workers (2018) examined the effects of hippotherapy versus pharmacotherapy for children with ADHD.  A total of 34 subjects with ADHD were randomly assigned at a 1:1 ratio to either 24 sessions of a twice-weekly hippotherapy or pharmacotherapy.  To assess therapeutic effects, the ARS was used pre-treatment and post-treatment as the primary outcome measure.  Secondary outcomes included the CBCL, Self-Esteem Scale (SES), PedsQL child and parent report version, Developmental Coordination Disorder Questionnaire (DCDQ), CGI-S, and quantitative electroencephalography (qEEG).  Both groups showed marked improvements in ADHD symptoms, CGI-S.  No significant differences between the 2 groups were detected regarding treatment outcome except thought problem subscales of CBCL; 12 weeks of hippotherapy improved attention, impulsivity/hyperactivity, and QOL.  The authors concluded that the findings of this trial is promising, but further studies are needed to evaluate the long-term clinical effectiveness of hippotherapy.

In a systematic review, White and associates (2020) examined the effectiveness of equine-assisted activities and therapies (EAAT) on behavioral, psychological and physical symptoms in the treatment of children with ADHD.  These researchers carried out a systematic search of data-bases (Cochrane Library, Embase, Emcare, ERIC, Medline, OTseeker, ProQuest, PsycINFO and Scopus) in February 2019.  Methodological quality of the studies was assessed using a modified McMaster critical appraisal tool.  A total of 10 studies met the inclusion criteria and overall, positive trends were identified in behavioral, psychological and physical outcome measures following the participation in an EAAT.  However, due to methodological constraints, caution is needed when interpreting these findings.  The authors concluded that while EAAT may offer some positive benefits for children with ADHD, however, further methodologically robust research is needed before definitive recommendations can be made.

Gilboa and Helmer (2020) examined the effectiveness of self-management intervention for attention and executive functions using equine-assisted occupational therapy (STABLE-OT) for school-aged children with ADHD.  A pre-post design was used in the intervention.  This trial was carried out at 2 riding school stables in Israel.  A total of 25 children (3 girls, and 22 boys, 6 to 14 years of age; male = 9.41 ± 1.75 years) diagnosed with ADHD participated in a therapeutic equestrian riding intervention.  The intervention included structured 45-min sessions for 12 weeks, while integrating child- and family-centered strategy acquisition and immediate feedback principles.  Their executive function (EF)  and occupational performance were evaluated pre- and post-intervention, using the Behavior Rating Inventory of Executive Function (BRIEF) and the Canadian Occupational Performance Measure (COPM).  Results showed a significant improvement in EF, as reflected by statistically significant decreases in the Global Executive Composite (GEC; t = 2.801; p = 0.01), metacognitive index (t = 3.873; p = 0.001), working memory (t = 2.476; p = 0.021), monitor (t = 2.359; p = 0.027), and initiation (t = 3.204; p = 0.004) subscales of the BRIEF questionnaire.  A statistically (p < 0.001) and clinically significant improvement was also found in the COPM performance and satisfaction scales.  The authors concluded that the findings of this study provided key preliminary evidence supporting the effectiveness of an individual equine-assisted OT intervention for children with ADHD.  It constituted an initial step toward clinical implementation of such therapeutic approaches, and is expected to spark further research in this area.

Perez-Gomez and colleagues (2020) carried out a systematic review of updated literature regarding EAAT in children with ADHD.  This review was performed until November 28, 2019 in 4 electronic data-bases: PubMed, Web of Science, Embase, and Google Scholar.  The inclusion criteria were intervention program, with pre- and post-data, based on EAAT, children with ADHD, as well as articles written in English.  A total of 9 articles were found that met the inclusion criteria.  The evidence level was C for 7 studies and B for 2 studies.  The level of conclusion was 3.  There were few studies with high methodological quality and there was a high heterogeneity in the variables included, what made that the level of evidence and conclusion were low.  The authors concluded that there is no account with enough studies of high methodological quality to determine that EAAT is an effective intervention for the treatment of children with ADHD.

Sexual Abuse and Emotional Stress

Guerino et al (2015) evaluated 2 women aged 18 and 21 years, who had suffered sexual violence when they were children between the ages of 6 and 7 years old.  The subjects did not have mental dysfunction but they were regular students registered at a school of special education; patients presented with severe motor limitation, difficulty with coordination, significant muscular retractions, thoracic and cervical kyphosis, cervical protrusion, which was basically a function of the postures they had adopted when they were victims of the sexual violence suffered in childhood.  The patients performed 20 sessions of 30-min of HPOT on a horse.  The activities were structured to stimulate coordination, proprioception, the vestibular and motor-sensorial systems for the improvement of posture, muscle activity and cognition.  The activities provided during HPOT sessions elicited alterations in postural adjustment resulting in 30 % improvement, 80 % improvement in coordination in, 50 % improvement in corporal balance and in sociability and self-esteem.  The authors concluded that HPOT proved to be an effective treatment method for coordination, balance and postural correction, and also improved the patients' self-esteem that had suffered serious emotional stress.  These preliminary findings need to be validated by well-designed studies.

Traumatic Brain Injury

In a single-case study, Erdman and Pierce (2016) described the use of hippotherapy with a boy who sustained a traumatic brain injury (TBI).  A 13-year old boy, 6 months after TBI received 12 physical therapy sessions, which included hippotherapy.  Improvements were noted in balance, strength, gross motor skills, gait speed, functional mobility, and reported participation.  The authors concluded that hippotherapy used with a 13-year old boy after TBI may have had a positive effect in the body structure, activity, and participation domains.  These preliminary findings need to be validated by well-designed studies.

Rigby and Grandjean (2016) summarized the physical benefits of therapeutic horseback riding and hippotherapy and suggested directions for future research.  Databases included Medline via Ebsco, Web of Science, PubMed, Google Scholar, and Academic Search Complete.  Articles were limited to those with full-text access published in English since 1987.  Acute and residual improvements in physical benefits, such as gross motor function (e.g., walking, running, jumping), spasticity, muscle symmetry, posture, balance, and gait occurred in adults and children with varying disabilities.  The benefits appeared to be greatest following multi-week interventions with 1 or more sessions per week.  Modest acute cardiovascular responses were observed during EAA/T with little or no evidence for training improvements in heart rate or blood pressure at rest or during riding.  The authors concluded that the present body of literature provided evidence that EAA/T are an effective means of improving many measures of physical health.  However, more controlled trials are urgently needed to strengthen the current knowledge base, establish dose-response characteristics of EAA/T, and explore the physiologic basis for the promising results suggested from the literature.

Marquez and associates (2020) stated that evaluation of the merit of hippotherapy in adults with acquired brain injury (ABI) is lacking.  These researchers examined if hippotherapy could improve motor function in adults with ABI.  They carried out a systematic review of all available controlled studies investigating the use of hippotherapy, in adults with ABI.  The primary outcome of interest was movement related function and secondary outcomes included impairment, QOL, and adverse events (AEs).  A total of 9 studies with 256 participants were included, of which 6 studies with 204 participants were included for meta-analysis.  When the data were pooled, hippotherapy did not produce statistically significant improvements in balance (standard mean difference [SMD] = 0.24, 95 % CI: -0.05, 0.54, p = 0.1) or gait parameters (SMD = -0.04, 95 % CI: -0.79, 0.72 p = 0.92) when compared to control and measured immediately after the intervention.  Long-term effects remain unknown due to lack of follow-up evaluation.  The authors concluded that the findings of this review suggested that hippotherapy is safe and well-tolerated by adults with ABI; short-term functional benefits were not associated with the use of hippotherapy.  These investigators stated that further high-quality research is needed before hippotherapy can be endorsed as a modality in adult neurological rehabilitation.

Kinney and colleagues (2019) stated that evidence-based treatments for service-related health conditions such as depression, PTSD, and TBI are not effective for all veterans.  Equine-assisted interventions (EAIs) are emerging as an additional treatment modality, but little is known regarding the safety and effectiveness of these interventions.  These investigators described the following features of the body of literature concerning equine-assisted interventions among veterans: veterans who have participated in equine-assisted interventions; specific characteristics of equine-assisted interventions in veterans; and the specific characteristics of research on equine-assisted interventions in veterans.  They conducted a systematic mapping review of peer-reviewed literature reporting on equine-assisted interventions among veterans between 1980 and 2017.  Searches of 9 databases yielded 3,336 unique records, 6 of which met the inclusion criteria and were reviewed.  Data relevant to the study aims were extracted and analyzed.  Equine-assisted interventions among veterans disproportionately targeted psychosocial outcomes and yielded promising results.  The detailed methods of EAI varied in the reported studies, ranging from communicating with the horse to mounted exercises.  There was also great diversity in outcome measurement.  The state of theoretical development regarding the mechanisms by which EAIs benefited the veteran population is currently under-developed.  Studies provided insufficient detail with respect to the description of the intervention, reasons for attrition, and the dose-response relationship.  The authors concluded that scientific development of EAIs targeting psychosocial outcomes among veterans is needed to establish their efficacy.  Targeted outcomes should be expanded, including outcomes more closely aligned with the nature of poly-traumatic injuries.  These investigators stated that future research must also emphasize the theoretical development of EAIs for veterans and thoroughly describe the participants, components of the intervention, factors contributing to attrition, and optimal dose-response relationships.

Wood and Fields (2019) comprehensively and systematically mapped peer-reviewed studies of hippotherapy published over 30 years, from 1980 through 2018, from the perspective of a phased scientific approach to developing complex interventions as a guide to future research and practice.  These researchers carried out a systematic mapping review of research of hippotherapy.  Searches of 9 databases produced 3,528 unique records; 78 full-text, English-written studies were reviewed, the earliest of which was published in 1998.  Data relevant to study aims were extracted electronically from these studies and analyzed using queries and pivot tables.  Children with CP and physical therapists were most prevalent as participants and providers.  Equine movement was hippotherapy's core component and mechanism.  Early-phase outcomes-oriented research predominated.  "Hippotherapy" was ambiguously defined as treatment strategies and comprehensive professional services, even as interventions grew more distinctive and complex.  A treatment theory and proof-of-concept related to motor outcomes were established, and efficacy research with comparison conditions emerged.  The authors concluded that continuing research of complex interventions that integrate hippotherapy, equine movement as a therapy tool, is needed.  These researchers stated that attention to gaps in foundational scientific work concurrent with continued piloting and efficacy work will aid in identifying the most promising interventions worthy of replication, evaluation and widespread adoption.

Substance Abuse Disorder

Kern-Godal et al (2016) noted that inclusion of horse-assisted therapy (HAT) in substance abuse disorder treatment is rarely reported.  The authors’ previous studies showed improved treatment retention and the importance of the patient-horse relationship.  This qualitative study used thematic analysis, within a social constructionist framework, to explore how 8 patients experienced contextual aspects of HAT's contribution to their substance abuse disorder treatment.  Participants described HAT as a "break from usual treatment".  However, 4 interrelated aspects of this experience, namely "change of focus", "activity", "identity", and "motivation," suggested HAT is more than just a break from usual substance abuse disorder treatment.  The stable environment is portrayed as a context where participants could construct a positive self: one which is useful, responsible, and accepted; more fundamentally, a different self from the "patient/self" receiving treatment for a problem.  The authors concluded that the implications extend well beyond animal-assisted or other adjunct therapies; and their relevance to broader substance abuse disorder policy and treatment practices warrants further study.

Autism Spectrum Disorder

In a pilot study, Ajzenman et al (2013) examined if hippotherapy increased function and participation in children with autism spectrum disorder (ASD).  These researchers hypothesized improvements in motor control, which might increase adaptive behaviors and participation in daily activities.  A total of 6 children with ASD aged 5 to 12 participated in 12 weekly 45-min hippotherapy sessions.  Measures pre- and post-hippotherapy included the Vineland Adaptive Behavior Scales-II and the Child Activity Card Sort.  Motor control was measured pre-intervention and post-intervention using a video motion capture system and force plates.  Postural sway significantly decreased post-intervention. Significant increases were observed in overall adaptive behaviors (receptive communication and coping) and in participation in self-care, low-demand leisure, and social interactions.  The authors concluded that these results suggested that hippotherapy has a positive influence on children with ASD and can be a useful treatment tool for this population.  The findings of this small, pilot study need to be validated by well-designed studies.

O'Haire (2013) stated that the inclusion of animals in therapeutic activities, known as animal-assisted intervention (AAI), has been suggested as a treatment practice for ASD.  These investigators presented a systematic review of the empirical research on AAI for ASD.  A total of 14 studies published in peer-reviewed journals qualified for inclusion.  The presentation of AAI was highly variable across the studies.  Reported outcomes included improvements for multiple areas of functioning known to be impaired in ASD, namely increased social interaction and communication as well as decreased problem behaviors, autistic severity, and stress.  The author concluded that despite unanimously positive outcomes, most studies were limited by many methodological weaknesses; this review showed that there is preliminary "proof of concept" of AAI for ASD and high-lighted the need for further, more rigorous research.

Srinivasan and colleagues (2018) noted that literature on effects of equine therapy in individuals with ASD has grown in recent times.  Equine therapy is an alternative multi-modal intervention that involves utilizing a horse to enhance core impairments in ASD.  Recent systematic reviews in this area have several limitations including inclusion of populations other than ASD, assessment of a variety of animal-assisted interventions other than equine therapy, and a failure to conduct quantitative analyses to provide accurate effect size estimates.  These investigators conducted a focused systematic review to address these limitations.  This review suggested that equine therapy has beneficial effects on behavioral skills and to some extent on social communication in ASD.  The authors concluded that the evidence for positive effects of equine therapy on perceptuo-motor, cognitive, and functional skills is currently limited.

Trzmiel and colleagues (2019) noted that the multi-factorial nature of ASD is the reason why complementary and alternative methods of treatment are sought to support the classic approach.  These researchers examined the effectiveness of EAAT in ASD patients based on a review of the literature.  They carried out a review of the literature and a meta-analysis in accordance with PRISMA guidelines.  PubMed, Cochrane Library, Web of Science, ClinicalTrials.gov and PEDro databases were searched until July 20, 2017.  Only articles published in English, in a journal with a review process, after 1999, with a control group or presentation of comparative pre-/post-therapy results in ASD patients, and clear inclusion/exclusion criteria were considered.  The methodological quality of the included studies was assessed using the Quality Assessment Tool for Quantitative Studies (QATQS); the meta-analysis of 3 studies was conducted.  A total of 15 studies with 390 participants (aged 3 to 16 years) were included.  The interaction between psychosocial functioning and EAAT was examined in most studies.  Improvement was reported in the following domains: socialization, engagement, maladaptive behaviors, and shorter reaction time in problem-solving situations after EAAT.  The meta-analysis revealed no statistically significant differences for the investigated effects.  The authors concluded that despite the need for further, more standardized research, the results of the studies included in this review allowed the authors to conclude that EAAT may be a useful form of therapy in children with ASD.  These researchers stated that it is impossible to draw universal conclusions due to the considerable discrepancies in therapeutic protocols and measurement instruments of the reviewed studies.  Furthermore, longitudinal trials, with standardized EAAT protocols and representative large sample groups are necessary.  Also, it is crucial to establish homogeneous tools to measure therapeutic progress and outcomes, especially with regard to social functioning.  The authors stated that the 2 main drawbacks of this review were a relatively small sample size, which increased the risk of a calculation error, and differences in research methodology, which greatly hindered the comparison of the results.

Down's Syndrome

De Miguel and colleagues (2018) noted that Down's syndrome is the main cause of intellectual disability and the most common human genetic alteration.  Motor impairments are among the most important alterations presented by Down's syndrome subjects.  Hippotherapy is currently being used as a therapy to correct those dysfunctions.  These investigators review published literature on the effect of hippotherapy on the gross motor function of people with Down's syndrome.  The bibliography in the following databases has been widely searched: CINAHL, Medline, the Cochrane Library, PEDro, Scopus, and Web of Science.  The journals Fisioterapia and Cuestiones de Fisioterapia have also been consulted.  The electronic literature search strategy was addressed in 2 thematic fields: Down's syndrome and hippotherapy.  Studies selection was carried out following inclusion and exclusion criteria and rejecting duplicate papers.  That search included articles published between 2000 and 2016.  A total of 23 articles were found, 15 of which were discarded for different reasons, leaving 8 valid ones.  The authors concluded that there is no strong evidence on the improvement of gross motor function in people with Down's syndrome after treatment with hippotherapy.  They stated that more studies with higher methodological quality are needed to verify the effectiveness of hippotherapy in the treatment of gross motor function in subjects with Down's syndrome.

In a pilot study, Portaro and colleagues (2020) examined if hippotherapy may influence balance and gait in patients with Down syndrome (DS).  A total of 15 male patients affected by DS underwent a 6-month hippotherapy protocol.  Stabilometric, baropodometric, and gait assessments were performed at baseline (T0) and at the end of the treatment (T1).  At baseline, DS patients showed a low bilateral hind-foot pressure percentage at the baropodometric analysis, a high center of pressure area in the closed-eye condition, a high center of pressure sway in open- and closed-eyes recordings, a high medio-lateral and antero-posterior velocity oscillations in the closed eye condition, and a reduced step-length and velocity.  After 6-month hippotherapy, DS patients had a significant bilateral higher hind-foot pressure percentage.  The stabilometric analysis revealed a lower center of pressure area in the closed-eye condition, and a significantly reduced center of pressure sway in open- and closed-eyes recordings.  In addition, DS patients showed lower medio-lateral and antero-posterior velocity oscillations in the closed eye condition.  Finally, hippotherapy significantly improved step length and velocity.  The authors concluded that the findings of this pilot study showed that hippotherapy determined functional improvement in gait speed, width, bilateral symmetry, and balance in DS.  These findings from an exploratory, pilot study need to be validated by well-designed studies.

In a case-series study, Moriello and associates (2020) documented gross motor function, gait parameter, and bladder control outcomes following physical therapy incorporating hippotherapy in children with DS.  A total of 4 children between 3 to 5 years of age received 8-weekly physical therapy sessions incorporating hippotherapy.  Outcome measures included the Gross Motor Function Measure-88 (GMFM-88), parental perception of function during every day activities, spatiotemporal parameters of gait and bladder control.  Total change scores on the GMFM-88 exceeded the standardized response mean in all 4 children, while scores on Dimension E improved in 2 children.  From the mothers' perspectives, all children showed at least some improvement in walking, running, and jumping; sitting, kneeling, and standing; symmetry and comfort; balance; coordination and social interactions and there were inconsistent changes in bladder control.  Only 1 child demonstrated changes greater than 20 % in any of the gait parameters.  The authors concluded that physical therapy incorporating hippotherapy may be a potential treatment to aid in improving gross motor function in children with DS, but 8 sessions may not be long enough to show major improvements in gait parameters or bladder control.  These researchers stated that further research in the form of larger controlled trials is needed to provide more support for the intervention in those with DS.

Chronic Pain (Low Back Pain)

In a randomized, single-blind, clinical trial, Rahbar and colleagues (2018) evaluated the effects of a hippotherapy simulator on pain, disability, and range of motion (ROM) of the spinal column in subjects with mechanical low back pain (LBP).  A total of 80 subjects were randomly assigned to either the control or intervention groups.  All subjects underwent routine physiotherapy.  In addition, the intervention group underwent hippotherapy with a hippotherapy simulator for 15 sessions, each lasting 15 mins.  Pain, disability, and ROM of the lumbar spinal column of the subjects were measured in the first and last physiotherapy sessions respectively.  Improvement in pain intensity was higher in the hippotherapy simulator group over the first 8 days of treatment (hippotherapy versus control point changes: Day 12: p = 0.010; after treatment: p = 0.005).  The hippotherapy simulator group had significantly higher improvement in disability score in comparison to the control group (p < 0.001); mean changes in the modified Schober test were not significant (p = 0.423).  The authors concluded that the hippotherapy simulator decreased pain and disability in subjects with LBP; however, no additional improvement in lumbar spine ROM was observed.   This study used a hippotherapy simulator; its findings need to be validated in the "real world" hippotherapy setting.

Collado-Mateo and colleagues (2020) noted that chronic pain is a complex global public health problem that affects the health status, QOL, ADL, and different work-related variables.  Riding a horse may lead to some benefits in chronic pain patients via the improvement of postural control and other biopsychosocial processes.  In a systematic review and meta-analysis, these investigators examined the effects of horse riding (with real or simulated horses) on chronic pain.  They carried out a literature search in accordance with PRISMA guidelines in Web of Science (WOS) and PubMed (Medline) electronic data-bases.  A total of 11 articles (7 RCTs) were selected to be included in the review.  Due to some risk of bias concerns, 2 meta-analyses (using post-intervention or change-from-baseline measures) were conducted utilizing Review Manager Software (RevMan 5.3).  Horse-riding simulators significantly reduced the pain levels of patients with LBP (p = 0.03, with a SMD of -1.14 and a 95 % CI: -2.16 to -0.11) using change-from-baseline measures.  However, the p-value in the meta-analysis with the post-intervention measures was 0.06.  Regarding interventions with real horses, it was not possible to conduct a meta-analysis due to the low number of studies.  The authors concluded that horse riding could be a useful exercise to reduce pain, but more studies are needed to make evidence-based recommendations and to compare the effects of horse-riding with real and simulated horses.  These studies should include larger and more homogeneous samples, as well as RCT designs.  Outcomes which include all psychological, physiological, and psychosocial outcomes are encouraged to clarify the different effects of EAAT and simulated horse interventions.

The authors stated that this study had several drawbacks.  First, only 11 articles (7 RCTs) were included, and the sources of pain (LBP, neck pain, arthritis, and multiple sclerosis) and interventions (real and simulated horses) were different.  Second, it was not possible to compare the 2 types of interventions (EAAT and simulators), and the available data do not allow the extraction of conclusions regarding the different benefits of EAAT and simulators in patients suffering from pain.  Therefore, further studies that compare the effects of real and simulated horses’ interventions are encouraged.  Another drawback was the risk of bias of the included studies, which made that the interpretation of results must be taken with caution.  Although all included studies in the meta-analysis were RCTs, there were some differences at baseline that could have affected the results.

Developmental Delays

In a case-series study, Kraft and colleagues (2019) examined  functional mobility in children with neurological impairments and documented gross motor delays, before and after receiving either hippotherapy or standard out-patient physical therapy (PT).  This report used data previously collected for a discontinued RCT, in which subjects received hippotherapy or standard out-patient clinic PT for a 12-week treatment period.  Results demonstrated both subjective and objective functional mobility improvements following treatment in subjects receiving hippotherapy and standard out-patient PT, as determined by the Peabody Developmental Motor Scales-2, the Pediatric Evaluation of Disability Inventory, and the Goal Attainment Scaling.  The authors concluded that when compared with standard out-patient PT, hippotherapy appeared to be a viable treatment strategy for children aged 2 to 5 years with neurological impairments and gross motor delays, however, additional research in this area is needed to validate these findings.

Improvement of Balance, Functional Capacity, and Cognition in Individuals With Alzheimer Disease

Borges de Araujo and colleagues (2019) stated that Alzheimer disease (AD) is a chronic, progressive dementia syndrome that features cognitive and behavioral symptoms, as well as physical and functional limitations that develop over the course of the disease.  As an activity that involves physical and cognitive aspects, EAT could be a useful therapeutic approach in conditions that involve physical and cognitive decline.  However, to-date, there are no reports of the use of this therapy in individuals with AD.  In a case-series study, these researchers examined the effects of EAT on balance, functional capacity, and cognition in older adults diagnosed with AD.  They enrolled 9 subjects, of both sexes, with a mean age of 79.7 (7.8) years.  The study intervention comprised 20 sessions of EAT.  These investigators evaluated subjects at baseline and at the end of the intervention.  Outcome measures were balance (force plate), functional capacity (Timed Up and Go test and 30-second chair stand test), and cognition (verbal fluency and Mini-Mental State Examination [MMSE]).  Comparison between the pre- and post-intervention time-points (Wilcoxon test) revealed significant improvements in balance (center of pressure in the anterior-posterior direction, p = 0.017) and functional capacity (Timed Up and Go test, p = 0.036, and 30-second chair stand test, p = 0.012).  The authors concluded that these findings provided evidence of an association between EAT and improved balance and functional capacity in older adults with AD, with no significant impact on cognitive performance.

Childhood Obesity

Schroeder and colleagues (2019) presented an exploratory case study that described the initial outcomes of the Equine-Assisted Positively Fit (EAPF) program.  Children with obesity (n = 3) and their caregivers were recruited to participate in the 8-session program.  Results indicated that treatment completers (n = 2) had a decrease in fat mass and fat mass percentage and an increase in fat-free mass and fat-free mass percentage.  Moreover, results from accelerometer measurements of physical activity indicated that subjects increased their moderate-to-vigorous physical activity, as well as reported increased self-efficacy for physical activity.  Qualitative data from the post-intervention focus group suggested children perceived the treatment acceptable and enjoyable.  The authors stated that the objective of this study was to carry out a mixed-method exploration of adding equine-assisted activities to a standardized curriculum for childhood obesity treatment.  More importantly, these findings provided a pathway to design clinical trials of the EAPF program in the future.  In particular, subjects found the treatment and its duration agreeable, evidenced by gains in several areas linked to successful outcomes associated with childhood obesity treatment, and reported that the equine activities were helpful.  In addition, subjects voiced a desire for more sessions, which suggested that this approach could have a unique effect on child motivation.  Lastly, these investigators observed distinct effects from the group therapy environment itself, primarily associated with the positive peer-to-peer and group leader-to-member interactions.  This warrants further research regarding how and when the inclusion of horses contributes in facilitative ways to a positive group climate.  Finally, given that childhood obesity is a critical public health issue, these researchers hope the description of this novel equine-assisted program will serve to jump-start more research on how time with horses might improve the health and well-being of children experiencing obesity.

The authors stated that the main drawbacks of this exploratory study entailed the small sample size (n = 3; and 2 completers), geographic location (i.e., rural setting in the southwest U.S.), as well as a lack of comparison or control group; thus, the effects of this intervention could not be generalized to other children experiencing obesity, nor could these researchers conclude which components of this multi-component model had the greatest impact on child outcomes.  Future studies are needed to isolate the effects of equine-assistance as compared with treatments without equine involvement, as well as replication studies to examine if positive results can be achieved when certain aspects of the intervention change, such as the location, facilitation team, and horses involved.  Lastly, another drawback of the small sample size and the research methodology was that these investigators were unable to render conclusions regarding the feasibility of executing a larger experimental trial; therefore, some elements required to test feasibility, such as subject acceptance of randomization procedures and calculation of recruitment rate, were not included in the study design.

Table: CPT Codes / HCPCS Codes / ICD-10 Codes

Code	Code Description
Information in the [brackets] below has been added for clarification purposes.   Codes requiring a 7th character are represented by "+":
HCPCS codes not covered for indications listed in the CPB:
S8940	Equestrian / hippotherapy, per session
ICD-10 codes not covered for indications listed in the CPB (not all-inclusive):
A88.1	Epidemic vertigo
E66.8	Other obesity [Childhood obesity]
E66.9	Obesity, unspecified [Childhood obesity]
F01.50 - F99	Mental and behavioral disorders
F50.00 - F50.9	Eating disorders
G20	Parkinson's disease
G30.0 - G30.9	Alzheimer's disease
G35	Multiple sclerosis
G71.00 - G71.9	Primary disorders of muscles
G80.0 - G80.9	Cerebral palsy
G89.21 – G89.4	Chronic pain
H81.01 - H82.9	Disorder of vestibular function and vertiginous syndromes in diseases classified elsewhere
H83.2X1 - H83.2X9	Labyrinthine dysfunction
I60.00 - I69.998	Cerebrovascular diseases
M00.00 - M99.9	Diseases of the musculoskeletal system and connective tissue
R25.0 - R29.9	Symptoms and signs involving the nervous and musculoskeletal systems
R42	Dizziness and giddiness
R48.0 - R48.9	Dyslexia and other symbolic dysfunctions, not elsewhere classified
R62.0 - R62.7	Lack of expected normal physiological development in childhood and adults
R63.2	Polyphagia
R68.0 - R68.89	Other general symptoms and signs
S00.00xA - S09.93xS	Injuries to head
S14.0xx+ - S14.9xx+ S2424.0xx+ - S24.9xx+ S3401x+ - S34.9xx+	Spinal cord injuries
T74.21 - T74.22	Sexual abuse, confirmed
T76.21 - T76.22	Sexual abuse, suspected
Z62.810	Personal history of physical and sexual abuse in childhood
Z62.813	Personal history of forced labor or sexual exploitation in childhood
Z68.54	Body mass index [BMI] pediatric, greater than or equal to 95th percentile for age [Childhood obesity]
Z73.3	Stress, not elsewhere classified [emotional]
Z85.00 - Z85.9	Personal history of malignant neoplasm [rehabilitation of cancer survivors]
Z87.81	Personal history of (healed) traumatic fracture
Z87.820	Personal history of traumatic brain injury
Z91.411	Personal history of adult physical and sexual abuse

The above policy is based on the following references: