Constraint-induced movement therapy (CIMT), also known as forced use movement therapy, is a therapeutic approach to rehabilitation of movement after stroke. It has purportedly been demonstrated to improve motor function in patients following cerebro-vascular accident (CVA). The intensity and schedule of delivery of CIMT is different from that of traditional physical rehabilitation approaches. Constraint-induced movement therapy entails a family of rehabilitation techniques with an underlying goal of inducing individuals with stroke to markedly increase the use of a more-affected upper extremity (UE) for many hours a day over a period of 2 to 3 weeks. The principal therapy involves constraining movements of the less-affected arm with a sling for 90 % of waking hours for the duration of therapy, while intensively training use of the more-affected arm.
Constraint-induced movement therapy has been employed for patients with chronic and sub-acute CVA, chronic traumatic brain injury, incomplete spinal cord injury, cerebral palsy, fractured hip, phantom limb pain, as well as musicians with focal hand dystonia. Although the improvement in motor function produced by CIMT in chronic stroke patients has been postulated to be associated with a shift in laterality of motor cortical activation toward the undamaged hemisphere, the exact mechanisms supporting rehabilitation-induced motor recovery are unclear.
In a randomized study (n = 66), van der Lee et al (1999) reported a small improvement in motor impairment in patients with chronic hemiparesis treated with CIMT. In another randomized study (n = 20), Dromerick et al (2000) found that CIMT resulted in a marked improvement in motor impairment.
Pierce et al (2004) examined the effectiveness of a program of traditional outpatient neurological rehabilitation that included home forced use. In total, 17 patients with chronic stroke and 1 patient with sub-acute stroke (mean time post-stroke = 27.6 months) completed an individualized program consisting of seven 2-hour treatment sessions composed of 1 hour of occupational therapy and 1 hour of physical therapy. Therapy sessions were completed over a 2- to 3-week period and included instruction on the use of a restraining mitt at home during functional activities. The authors stated that the preliminary results suggested that the forced-use component of CIMT may be effective when applied within a traditional outpatient rehabilitation program.
In an observer-blinded randomized control trial (n = 69), Suputtitada et al (2004) reported that CIMT of unaffected upper extremities has an advantage over conservative treatment for chronic stroke patients. The CIMT group received 6 hours of daily affected-upper-extremity training and restrained unaffected upper extremities for 5 days per week, totally 2 weeks. The control group received bimanual-upper-extremity training by conservative neuro-developmental technique without restrained unaffected upper extremities for 2 weeks. These authors concluded that CIMT may be an effective technique of improving motor activity and exhibiting learned non-use.
In a single-blinded randomized controlled trial, Page et al (2004) determined the effectiveness of a modified CIMT protocol for patients with chronic stroke. A total of 17 patients who experienced stroke more than 1 year before study entry and who had upper-limb hemiparesis and learned non-use enrolled in this study. Seven patients participated in structured therapy sessions emphasizing more affected arm use in valued activities, 3 times a week for 10 weeks. Their less affected arms were also restrained 5 days/week for 5 hours (modified CIMT). Four patients received regular therapy with similar contact time to modified CIMT. Six patients received no therapy (control). These investigators concluded that modified CIMT may be an effective method of improving function and use of the more affected arms of chronic stroke patients.
The findings of Suputtitada et al (2004) and Page et al (2004) are in agreement with the observations of Van Peppen et al (2004) and Yen et al (2005). Van Peppen and colleagues noted that there is strong evidence for therapies that are focused on functional training of the upper limb such as CIMT in improving functional outcomes after stroke; while Yen and associates reported that modified CIMT is useful in improving the function of the affected upper extremity in stroke patients (n = 30). Subjects in the modified CIMT group received a 2-week course of modified CIMT that entailed massed training of the affected arm without any physical restriction of the intact one.
Stein (2004) stated that younger stroke patients appear to have a greater ability to recover from stroke and are likely to benefit substantially from treatments that facilitate plasticity-mediated recovery. The use of new exercise treatments, such as CIMT, robot-aided rehabilitation, and partial body weight supported treadmill training are being studied intensively, and are likely to ultimately be incorporated into standard post-stroke rehabilitation.
Moreover, in a randomized controlled pilot study (n = 10), Page et al (2005) compared the effectiveness of modified CIMT to traditional rehabilitation in acute stroke patients exhibiting upper limb hemiparesis (less than 14 days post-stroke). Five patients were administered modified CIT, consisting of structured therapy emphasizing more affected arm use in valued activities 3 days/week for 10 weeks and less affected arm restraint 5 days/week for 5 hours. Five other patients received half sessions of traditional motor rehabilitation for the affected arm, which included affected limb manual dexterity exercises and stretching, as well as compensatory strategies with the unaffected limb. The traditional rehabilitation regimens occurred 3 days/week for 10 weeks. These researchers concluded that modified CIMT is a promising regimen for improving more affected limb use and function in acute CVA. However, larger confirmatory studies need to be performed.
The Veterans Health Administration's clinical practice guideline for the management of stroke rehabilitation (2003) noted that the use of CIMT should be considered for a select group of patients, i.e., those with 20 degrees of wrist extension and 10 degrees of finger extension, who have no sensory and cognitive deficits.
Guidelines from the British Intercollegiate Stroke Working Party state that “[c]onstraint-induced therapy to increase the use of the affected arm should be considered in patients with at least 10 degrees of active wrist and finger extension, who are more than a year post-stroke and who can walk independently without an aid.”
Ottawa Panel Guidelines (2006) state that "there is sufficient evidence to recommend the use of CIMT during the acute, subacute, or chronic phases of rehabilitation for improving dexterity, motor function, and functional status in stroke patients capable of some active finger and wrist extension."
Although CIMT has been demonstrated to provide a small positive effect on upper limb function in patients who require upper limb training for hemiplegia following stroke, a systematic evidence review (Lannin et al, 2005) has questioned the statistical and clinical significance of this effect. The systematic evidence review also notes that existing studies have only compared the effectiveness of CIMT to compensatory or bimanual training techniques, and not to techniques designed to practice re-training isolated active movement in the hemiplegic arm.
In a systematic review of randomized controlled trials on CIMT following stroke, Hakkennes and Keating (2005) stated that results indicate that CIMT may improve upper limb function following stroke for some patients when compared to alternative or no treatment. The authors stated that rigorous evaluation of CIMT using well-designed and adequately powered trials is required to evaluate the efficacy of different protocols on different stroke populations and to assess impact on quality of life, cost and patient/care-giver satisfaction.
Constraint-induced movement therapy is being investigated for use in other conditions, including cerebral palsy (CP).
In a randomized, controlled study, Taub et al (2004) evaluated the applicability of CIMT to young children with CP (n = 18, aged 7 to 96 months). Patients were randomly assigned to receive either pediatric CIMT or conventional treatment. Pediatric CIMT involved promoting increased use of the more-affected arm and hand by intensive training (using shaping) of the more-impaired upper extremity for 6 hours/day for 21 consecutive days coupled with bi-valved casting of the child's less-affected upper extremity for that period. Patients were followed for 6 months. The authors found that pediatric CIMT produced major and sustained improvement in motoric function in the young children with hemiparesis. The results of this trial are promising, but its finding needs to be validated by studies with larger sample size and longer follow-up to ensure that gains that might occur persist for over 2 years as proposed by Winstein et al (2003).
In a review of CIMT and forced use in children with hemiplegia, Charles and Gordon (2005) stated that while both forced use and CIMT appear to be promising for improving hand function in children with hemiplegia, the data are limited. Substantially more work must be performed before this approach can be advocated for general clinical use.
In an open-label, pilot study (n = 6), Tuite and colleagues (2005) reported that CIMT did not produce any substantial or consistent kinematic improvements in the affected limb of patients with Parkinson's disease (Hoehn and Yahr stage II to III).
In a pilot study (n = 9), Naylor and Bower (2005) assessed the effectiveness of modified CIMT in young children with hemiplegia. Assessment was at entry to the study and subsequently at 4-weekly intervals. A 4-week baseline period with no hand treatment, controlling for maturation, was followed by a 4-week treatment period and a second 4-week period with no hand treatment to measure carry-over. Treatment consisted of twice-weekly 1-hour sessions of structured activities with a therapist and a home program for non-treatment days. Only verbal instruction and gentle restraint of the unaffected arm were used to encourage use of the affected arm. Patients (6 males, 3 females; median age of 31 months, range of 21 to 61 months) presenting with congenital spastic hemiplegia (5 right side, 4 left side) were involved in the study. Changes in hand function were evaluated with the Quality of Upper Extremity Skills Test. Improvement was seen throughout the study with statistical significance, using the Wilcoxon signed rank test, of 0.01 immediately after treatment. Results of this pilot study suggested that this modification of CIMT may be an effective way of treating young children with hemiplegia. The authors noted that future work is planned to consolidate and develop these results.
In a single-blinded, randomized, controlled study (n = 22), Charles and colleagues (2006) examined the effectiveness of CIMT, modified to be child-friendly, in children with hemiplegic CP. Patients (8 females, 14 males; mean age of 6 years and 8 months; range of 4 to 8 years) were randomized to either an intervention group (n = 11) or a delayed treatment control group (n = 11). Children wore a sling on their non-involved upper limb for 6 hours per day for 10 out of 12 consecutive days and were engaged in play and functional activities. Children in the treatment group demonstrated improved movement efficiency and dexterity of the involved upper extremity, which were sustained through the 6-month evaluation period, as measured by the Jebsen-Taylor Test of Hand Function and fine motor-subtests of the Bruininks-Oseretsky Test of Motor Proficiency (p < 0.05 in both cases). Initial severity of hand impairment and testing compliance were strong predictors of improvement. Care-givers reported significant increases in involved limb frequency of use and quality of movement. However, there was no change in strength, sensibility, or muscle tone (p > 0.05 in all cases). Results of this study suggested that for a carefully selected subgroup of children with hemiplegic CP, CIMT modified to be child-friendly, appears to be effective in improving movement efficiency of the involved upper extremity.
It is interesting to note that the children in the control group who subsequently received CIMT did not improve after the intervention. There was no difference between the pre-test and 6-month follow-up scores for this group before cross-over, thus, a ceiling effect is unlikely. The authors stated that overall CIMT improved involved arm and hand function in a select group of children with hemiplegic CP. However, this intervention may not be advisable for all children with hemiplegia. The child's age and severity of hand function need to be considered. Determining if forced-use is more appropriate for some ages and CIMT more appropriate for others, as well as determining the optimal dose response and potential adverse effects, is also important.
In a Cochrane review on the use of CIMT in the treatment of the upper limb in children with hemiplegic CP, Hoare et al (2007) found a significant treatment effect using modified CIMT in a single trial. A positive trend favoring CIMT and forced-use was also demonstrated. The authors concluded that given the limited evidence, the use of CIMT, modified CIMT and forced-use should be considered experimental in children with hemiplegic CP. They noted that further research using adequately powered randomized controlled trials, rigorous methodology and valid and reliable outcome measures is essential to provide higher level support of the effectiveness of CIMT for children with hemiplegic CP.
A systematic evidence review by Huang and colleagues (2009) concluded that evidence demonstrated an increased frequency of use of the upper extremity following CIMT for children with hemiplegic CP. The author found, however, that the critical threshold for intensity that constituted an adequate dose could not be determined from the available research. A total of 21 studies were included in the review (n = 168, range of 1 to 41): 5 RCTs (n = 114); 2 pretest post-test design with control group (n = 16); 3 1-group pretest post-test designs (n = 27); 3 single-subject studies (n = 11); and 8 case report designs (n = 11). The RCTs and pretest post-test study designs had validity scores between 7 and 11 out of 16. The 2 1-group designs that were assessed had scores of 5 and 7 out of 11. Study duration ranged from 1 week to 18 months. Four studies allowed computation of effect size and 1 additional study provided effect size (eta values) within the paper. One of these studies reported 5 outcome measures at the body functions and structure level of which one (Modified Ashworth Scale – shoulder) was statistically significant (p < 0.05). These 5 studies reported a total of 14 different activity level outcomes of which 5 were statistically significant (p < 0.05): Caregiver Functional Use Survey -- How frequently (1 study); Assisting Hand Assessment (one study); Emerging Behaviour Scale (1 study); Pediatric Motor Activity Log – Amount of use (1 study); and WeeFIM Self-Care (1 study). All significant effect size values were medium to large (d = 0.6 to 1.16). The other 16 studies reported positive outcomes in fine motor and functional activities post treatment and up to 12 months follow-up. A critique of this systematic evidence review by the Centre for Reviews and Dissemination (2010) noted that the primary study sizes were small and the conclusions of this systematic evidence review were based on a small number of good-quality studies. The CRD critique concluded: "Given the uncertainties around the review methodologies used, potential that relevant studies were missed and paucity and variability in the evidence presented, the authors conclusions are unlikely to be reliable."
Mark and colleagues (2008) examined if CIMT may benefit chronic upper extremity hemiparesis in progressive multiple sclerosis (MS). A total of 5 patients with progressive MS, who had chronic upper extremity hemiparesis and evidence for learned non-use of the paretic limb in the life situation, underwent 30 hours of repetitive task training and shaping for the paretic limb over 2 to 10 consecutive weeks, along with physical restraint of the less-affected arm and a "transfer package" of behavioral techniques to reinforce treatment adherence. Subjects showed significantly improved spontaneous, real-world limb use at post-treatment and 4 weeks post-treatment, along with improved fatigue ratings and maximal movement ability displayed in a laboratory motor test. The authors concluded that these findings suggested for the first time that slowly progressive MS may benefit from CIMT. Moreover, they stated that further studies are needed to determine the retention of treatment responses.
Sakzewski and co-workers (2009) systematically reviewed the effectiveness of non-surgical upper-limb therapeutic interventions for children with congenital hemiplegia. The Cochrane Central Register of Controlled Trials, Medline, CINAHL, AMED, Embase, PsycINFO, and Web of Science were searched up to July 2008. Data sources were randomized or quasi-randomized trials and systematic reviews. A total of 12 studies and 7 systematic reviews met the selection criteria. Trials had strong methodological quality (Physiotherapy Evidence Database [PEDro] scale greater than or equal to 5), and systematic reviews rated strongly (AMSTAR [Assessment of Multiple Systematic Reviews] score greater than or equal to 6). Four interventions were identified: (i) intra-muscular botulinum toxin A (Botox) combined with upper-limb training; (ii) CIMT; (iii) hand-arm bi-manual intensive training; and (iv) neurodevelopmental therapy. Data were pooled for upper-limb, self-care, and individualized outcomes. There were small-to-medium treatment effects favoring intra-muscular Botox and occupational therapy, neurodevelopmental therapy and casting, CIMT, and hand-arm bi-manual intensive training on upper-limb outcomes. There were large treatment effects favoring intra-muscular Botox and upper-limb training for individualized outcomes. No studies reported participation outcomes. The authors concluded that no one treatment approach seems to be superior; however, Botox injections provide a supplementary benefit to a variety of upper-limb-training approaches. They stated that additional research is needed to justify more-intensive approaches such as CIMT and hand-arm bi-manual intensive training.
In a prospective, repeated-measures design study, Brunner and colleagues (2011) examined eligibility for modalities such as CIMT and modified CIMT (mCIMT) in the sub-acute phase after stroke and defined the share of patients who should be offered this treatment. A total of 100 consecutive patients with arm paresis 1 to 2 weeks post-stroke were screened. Eligible for CIMT were patients who were cognitively intact, medically stable, and able to extend the wrist and 3 fingers 10° as a lower limit. The active range of motion was registered, and motor function was assessed by the Action Research Arm Test (ARAT) and the Nine Hole Peg Test at 1 to 2 weeks, 4 weeks, and 3 months post stroke. From 100 patients, 54 were excluded from motor assessment, mostly due to cognitive impairments. Of the remaining 46 patients, 21 (46 %) were eligible according to motor function of the hand at 1 to 2 weeks post-stroke, whereas in the other patients motor function was either too good or too poor. The share of patients eligible declined to 31 % after 4 weeks and 15 % after 3 months. Within 3 months, 60 % reached reasonable dexterity, expressed by an ARAT score greater than or equal to 51, all receiving standard rehabilitation. The authors concluded that results indicate that eligibility for CIMT or mCIMT should not be considered before 4 weeks post-stroke because much improvement in arm function was shown to occur during the first month post-stroke with standard rehabilitation.
In a systematic review, Nijland et al (2011) stated that CIMT is a commonly used intervention to improve upper limb function after stroke. However, the effectiveness of CIMT and its optimal dosage during acute or sub-acute stroke is still under debate. To examine the literature on the effects of CIMT in acute or sub-acute stroke. A literature search was performed to identify RCTs; studies with the same outcome measure were pooled by calculating the mean difference. Separate quantitative analyses for high-intensity and low-intensity CIMT were applied when possible. Five RCTs were included, comprising 106 participants. The meta-analysis demonstrated significant mean differences in favor of CIMT for the Fugl-Meyer arm, the Action Research Arm Test, the Motor Activity Log, Quality of Movement and the Grooved Pegboard Test. Non-significant mean difference in favor of CIMT were found for the Motor Activity Log, Amount of Use. Separate analyses for high-intensity and low-intensity CIMT resulted in significant favorable mean differences for low-intensity CIMT for all outcome measures, in contrast to high-intensity CIMT. This meta-analysis demonstrated a trend toward positive effects of high-intensity and low-intensity CIMT in acute or sub-acute stroke, but also suggests that low-intensity CIMT may be more beneficial during this period than high-intensity CIMT. However, these results were based on a small number of studies. Therefore, they concluded that more trials are needed applying different doses of therapy early after stroke and a better understanding is needed about the different time windows in which underlying mechanisms of recovery operate.
Constraint-induced aphasia therapy (CIAT) is an intensive language training program. According to the American Stroke Association (2006), this short-term therapy takes the 3 principles of CIMT and applies them to speech therapy. In speech therapy, constraint means avoiding the use of compensatory strategies such as gesturing, drawing, writing, etc.; forced use means communicating by talking; and massed practice means 2 to 4 hours of speech therapy a day. Preliminary investigations suggested that these principles may be effective in aphasia rehabilitation, but research is still very early. Thus, CIAT is provided in a communicative environment constraining patients to practice systematically speech acts with which they have difficulty. It has been used in the treatment of chronic aphasia.
Szaflarski and colleagues (2008) stated that CIAT offers potential benefits to individuals with history of aphasia-producing ischemic stroke. In a pilot study, these investigators implemented the original German CIAT protocol, refined the treatment program, and attempted to confirm its effectiveness in patients with chronic aphasia. They translated and modified the original CIAT protocol to include a hierarchy of individual skill levels for semantic, syntactic, and phonological language production, while constraining non-use behaviors. A total of 3 male subjects with moderate-to-severe post-stroke aphasia received CIAT 3 to 4 hours/day for 5 consecutive days. Pre- and post-testing included formal language evaluation, linguistic analysis of story retell, and mini-Communication Activity Log (mini-CAL). Substantial improvements in comprehension and verbal skills were noted in 2 subjects with an increase in the total number of words (31 % and 95 %) and in number of utterances for story retell task (57 % and 75 %). All subjects reported an improvement on at least 1 linguistic measure. No subjective improvements on mini-CAL were noted by any of the subjects. The authors concluded that given that the duration of treatment was only 1 week, these linguistic improvements in post-stroke aphasia subjects were remarkable. The results indicated that the CIAT protocol used in this study may be a useful tool in language restoration following stroke. The authors stated that these preliminary findings should be confirmed in a larger, randomized study.
Cherney and associates (2008) summarized evidence for intensity of treatment and constraint-induced language therapy (CILT) on measures of language impairment and communication activity/participation in individuals with stroke-induced aphasia. A systematic search of the aphasia literature using 15 electronic databases (e.g., PubMed, CINAHL) identified 10 studies meeting inclusion/exclusion criteria. A review panel evaluated studies for methodological quality. Studies were characterized by research stage (i.e., discovery, efficacy, effectiveness, cost-benefit/public policy research), and effect sizes (ESs) were calculated wherever possible. In chronic aphasia, studies provided modest evidence for more intensive treatment and the positive effects of CILT. In acute aphasia, 1 study evaluated high-intensity treatment positively; no studies examined CILT. Four studies reported discovery research, with quality scores ranging from 3 to 6 of 8 possible markers. Five treatment efficacy studies had quality scores ranging from 5 to 7 of 9 possible markers. One study of treatment effectiveness received a score of 4 of 8 possible markers. The authors concluded that although modest evidence exists for more intensive treatment and CILT for individuals with stroke-induced aphasia, the results of this review should be considered preliminary.