Ankle Orthoses, Ankle-Foot Orthoses (AFOs), and Knee-Ankle-Foot Orthoses (KAFOs)

Number: 0565

Table Of Contents

Policy

Scope of Policy

This Clinical Policy Bulletin (CPB) addresses ankle orthoses, ankle-foot orthoses (AFOs), and knee-ankle-foot orthoses (KAFOs).

1. Medical Necessity

   Aetna considers ankle orthoses, ankle-foot orthoses (AFOs), and knee-ankle-foot orthoses (KAFOs) medically necessary (unless otherwise stated) durable medical equipment (DME) according to the criteria set forth below. See background section of this CPB for descriptions of the orthotics discussed in this policy.

   1. Orthosis (orthopedic brace) and/or prosthesis

      An orthosis (orthopedic brace) and/or prosthesis is considered medically necessary when:

      1. Care is prescribed by a physician, nurse practitioner, podiatrist or other health professional who is qualified to prescribe orthotics and/or prosthetics according to State law; and
      2. The orthosis or prosthesis will significantly improve or restore physical functions required for mobility related activities of daily living (MRADL's); and
      3. The member’s participating physician or licensed health care practitioner has determined that the orthosis or prosthesis will allow the member to perform ADLs based on physical examination of the member; and
      4. The orthosis or prosthesis is provided within six months of the date of prescription; and
      5. The orthotic or prosthetic services are performed by a duly licensed and/or certified, if applicable, orthotic and/or prosthetic provider. (All services provided must be within the applicable scope of practice for the provider in their licensed jurisdiction where the services are provided); and
      6. The services provided are of the complexity and nature to require being provided by a licensed or certified professional orthotist and/or prosthetist or provided under their direct supervision by a licensed ancillary person as permitted under state laws. (Services may be provided personally by physicians and performed by personnel under their direct supervision as permitted under state laws, as physicians are not licensed as orthotists and/or prosthetists); and
      7. The certified professional orthotist or prosthetist must be in good standing with one or more of the following:
         
         
         1. American Board for Certification (orthotics, prosthetics, pedorthics) (ABC); or
         2. Board of Certification/Accreditation (prosthetics, orthotics) (BOC); or
         3. licensed by the state in which services are provided (where legally required);

   2. Ankle orthotics

      1. Ankle air-stirrups (e.g., Air Cast) are considered medically necessary DME when used after an ankle injury (fractures or sprains). Air-stirrups are considered experimental, investigational, or unproven for chronically unstable ankles or to prevent ankle re-injury because of a lack of adequate evidence of the effectiveness of ankle air-stirrups for these indications.  See CPB 0009 - Orthopedic Casts, Braces, and Splints;
      2. Reusable elastic ankle sleeves are considered medically necessary DME for use to treat an ankle injury (acute and rehabilitative stages). Use of elastic ankle sleeves in a chronically unstable ankle or to prevent ankle re-injury is considered experimental, investigational, or unproven because of a lack of adequate evidence of the effectiveness of elastic ankle sleeves for these indications;
      3. Lace-up ankle braces are considered medically necessary DME when used in members with ankle injuries, when used in members with chronically unstable ankles, or when used to prevent ankle re-injury;
      4. Orthopedic ankle cast-braces are considered medically necessary DME when used after an ankle injury (fractures or sprains);
      5. Orthoplast ankle stirrups are considered medically necessary DME for use after an acute injury. Use of orthoplast ankle stirrups in chronically unstable ankles or to prevent ankle re-injury is considered experimental, investigational, or unproven because of a lack of adequate evidence of the effectiveness of orthoplast ankle stirrups for these indications;
      6. Post-operative rehabilitation ankle braces are considered medically necessary when applied within 6 weeks of surgery. Such post-operative rehabilitative braces are considered an integral part of surgery.  See also CPB 0009 - Orthopedic Casts, Braces, and Splints;
      7. Rigid ankle casts are considered medically necessary DME when used to treat ankle fractures.  Rigid ankle casts are considered experimental, investigational, or unproven when used after ankle sprains, for chronically unstable ankles, or when used to prevent re-injury because of a lack of adequate evidence of the effectiveness of rigid ankle casts for these indications;
      8. Semi-rigid ankle casts are considered medically necessary DME when used to treat ankle sprains.  Semi-rigid ankle casts are considered experimental, investigational, or unproven when used after ankle fractures, for use in chronically unstable ankles, or when used to prevent re-injury because of a lack of adequate evidence of effectiveness of semi-rigid ankle cases for these indications;
      9. Unna boots are considered medically necessary DME when used after ankle sprains and other soft tissue injuries.  Unna boots are considered experimental, investigational, or unproven when used after ankle fractures, or when used in chronically unstable ankles or to prevent re-injury because of a lack of adequate evidence of the effectiveness of Unna boots for these indications.  See CPB 0009 - Orthopedic Casts, Braces, and Splints;

   3. Ankle Foot Orthoses (AFOs) and Knee Ankle Foot Orthoses (KAFOs)

      1. AFOs and KAFOs used in minimally ambulatory or non-ambulatory persons

         Static or dynamic positioning ankle foot orthoses (ankle contracture splints) and foot drop splints

         1. Static or dynamic positioning ankle foot orthoses are considered medically necessary DME if all of the following criteria are met:

            1. The static or dynamic positioning ankle-foot orthoses is used as a component of a therapy program that includes active stretching of the involved muscles and/or tendons, and
            2. The contracture is interfering or expected to interfere significantly with the member's functional abilities, and
            3. There is a reasonable expectation of the ability to correct the contracture, and
            4. The member has a plantar flexion contracture of the ankle with dorsiflexion on passive range of motion testing of at least 10 degrees (i.e., a non-fixed contracture).

            If a static or dynamic positioning ankle-foot orthosis is used for the treatment of a plantar flexion contracture, the pre-treatment passive range of motion must be measured with a goniometer and documented in the medical record.  There must be documentation of an appropriate stretching program carried out by professional staff (in a nursing facility) or caregiver (at home).

            A static or dynamic positioning ankle-foot orthosis is considered medically necessary for plantar fasciitis.

            If a static or dynamic positioning ankle-foot orthosis is considered medically necessary, a replacement interface is also considered medically necessary DME as long as the member continues to meet medical necessity criteria for the splint. Up to 1 replacement interface per 6 months is considered medically necessary.

            A static or dynamic positioning ankle-foot orthosis and replacement interface is not considered medically necessary for the following indications:

            • Fixed contractures;
            • Members with foot drop but without an ankle flexion contracture.

            Note: In addition, under HMO plans, a static or dynamic positioning ankle-foot orthosis and replacement interface is not considered medically necessary when it is used solely for the prevention or treatment of a heel pressure ulcer because Medicare does not consider it medically necessary for these indications.

            A component of a static or dynamic positioning ankle-foot orthosis that is used to address positioning of the knee or hip is considered experimental, investigational, or unproven because the effectiveness of this type of component is not established.

         2. Foot drop splint/recumbent positioning device

            Aetna's HMO plans do not consider a foot drop splint/recumbent positioning device or replacement interface medically necessary.  A foot drop splint/recumbent positioning device and replacement interface is not considered medically necessary under HMO plans when it is used solely for the prevention or treatment of a heel pressure ulcer because Medicare does not consider it medically necessary for these indications.  A foot drop splint/recumbent positioning device and replacement interface is not considered medically necessary for members with foot drop who are non-ambulatory because there are other more appropriate treatment modalities.

         3. Additions to AFOs and KAFOs

            Additions to AFOs or KAFOs are not considered medically necessary if either the base orthosis is not medically necessary or the specific addition is not medically necessary.

      2. AFOs and KAFOs used in ambulatory persons

         1. AFOs in ambulatory members

            Ankle-foot orthoses (AFO) are considered medically necessary DME for ambulatory members with weakness or deformity of the foot and ankle, which require stabilization for medical reasons, and have the potential to benefit functionally.  Members prescribed custom-made “molded-to-patient-model” AFOs must also meet the criteria set forth in section c. 'Molded-to-patient model AFO's and KAFO's in ambulatory members', below.  AFOs are not considered medically necessary for ambulatory members who do not meet these medical necessity criteria.

            Aetna's HMO plans do not consider AFOs and any related addition medically necessary when used solely for the treatment of edema and/or for the prevention or treatment of a heel pressure ulcer in ambulatory patients, as Medicare does not consider AFO's medically necessary for these indications.

            Additions to AFOs or KAFOs are not considered medically necessary if either the base orthosis is not medically necessary or the specific addition is not medically necessary.  (Note: Customized Noodle TA AFO and the PHAT dynamic carbon fiber AFO or similar (i.e., custom carbon strut and/or propulsion or neuro foot plates) are considered non-covered deluxe items).

            Aetna considers AFOs experimental, investigational, or unproven for the treatment of osteoarthritis of the knee because their effectiveness for this indication has not been established.

         2. KAFOs in ambulatory members

            Knee-ankle-foot orthoses (KAFO) are considered medically necessary DME for ambulatory members for whom an ankle-foot orthosis is considered medically necessary and for whom additional knee stability is required.  Members prescribed custom-made “molded-to-patient model” KAFOs must also meet the criteria set forth in section c. 'Molded-to-patient model AFO's and KAFO's in ambulatory members', below.  KAFOs are not medically necessary and are not covered for ambulatory members who do not meet these coverage criteria.

            Aetna's HMO plans do not consider KAFOs and any related addition medically necessary when used solely for the treatment of edema and/or for the prevention or treatment of a heel pressure ulcer in ambulatory members, as Medicare does not consider KAFO's medically necessary for these indications.

         3. Molded-to-patient model AFO's and KAFO's in ambulatory members

            Custom-made AFOs and KAFOs that are “molded-to-patient-model” are considered medically necessary DME for ambulatory members when the basic medical necessity criteria listed in the sections for 'AFOs in ambulatory members' and 'KAFOs in ambulatory members' (above) are met and one of the following criteria is met:

            1. The condition necessitating the orthosis is expected to be permanent or of longstanding duration (more than 6 months); or
            2. There is a need to control the knee, ankle or foot in more than 1 plane; or
            3. The member could not be fitted with a pre-fabricated (off-the-shelf) AFO; or
            4. The member has a documented neurological, circulatory, or orthopedic status that requires custom fabricating over a model to prevent tissue injury; or
            5. The member has a healing fracture that lacks normal anatomical integrity or anthropometric proportions;

         4. Additions to AFOs and KAFOs

            Additions to AFOs and KAFOs are not considered medically necessary if either the base orthosis is not medically necessary and/or the specific addition is not medically necessary. 

         5. Concentric adjustable torsion-style mechanisms

            Concentric adjustable torsion style mechanisms used to assist knee joint extension are considered medically necessary for members who require knee extension assist in the absence of any co-existing joint contracture. 

            Concentric adjustable torsion style mechanisms used to assist ankle joint plantarflexion or dorsiflexion are considered medically necessary for members who require ankle plantar or dorsiflexion assist in the absence of any co-existing joint contracture. 

            A dynamic adjustable ankle extension/flexion device is considered medically necessary for treatment of contractures.

         6. Microprocessor-controlled KAFOs

            Electronic KAFOs (e.g., the Sensor Walk Electronic KAFO, C-Brace Orthotronic Mobility System) are considered experimental, investigational, or unproven because of insufficient evidence that they improve ambulation compared to standard KAFOs.

      3. General Notes

         1. Prophylactic orthotics

            Aetna does not consider ankle orthotics, AFOs, and KAFOs medically necessary treatment of disease when used to prevent injury in a previously uninjured ankle or knee.  Such use is solely preventive, and therefore is considered not considered medically necessary treatment of disease or injury.  In addition, many Aetna plans exclude coverage of safety items.  See CPB 0623 - Safety Items.

         2. Repairs and replacements

            Repairs to a medically necessary ankle orthosis, AFO, or KAFO due to wear and tear are considered medically necessary DME when they are needed to make the orthosis functional.  Replacement of a complete ankle orthosis, AFO, or KAFO or component of these orthoses due to a significant change in the member's condition or irreparable wear is considered medically necessary DME if the device is still medically necessary.

         3. Shoes

            Please see CPB 0451 - Foot Orthotics for medical necessity criteria for shoes and related items that are an integral part of a leg brace.

         4. Socks

            Socks used in conjunction with ankle orthoses, AFOs, or KAFOs are not covered because socks do not meet the contractual definition of durability for covered DME.

         5. Spare orthotics

            Identical spare orthotics purchased for the member's convenience is not considered medically necessary.  More than 1 set of different orthotics, however, may be medically necessary.

         6. Sports orthotics

            Aetna does not consider ankle orthotics, AFOs, and KAFOs medically necessary if they are to be used only during participation in sports.  Such use is considered not medically necessary, as participation in sports is considered an elective activity.

2. Experimental, Investigational, or Unproven

   The following DME (not all-inclusive) is considered experimental, investigational, or unproven because the effectiveness for this indication has not been established:

   Stabilizing shoes for ankle injuries (acute or chronic). Note: In addition, most plans contractually exclude foot orthotics.  Please check benefit plan descriptions.  See CPB 0451 - Foot Orthotics.

3. Related Policies

   • CPB 0009 - Orthopedic Casts, Braces and Splints
   • CPB 0451 - Foot Orthotics
   • CPB 0623 - Safety Items
   • CPB 0696 - Suit Therapy

Background

An orthosis (brace) is a rigid or semi-rigid device that is used for the purpose of supporting a weak or deformed body member or restricting or eliminating motion in a diseased or injured part of the body.  An orthosis can be either pre-fabricated or custom-fabricated.

Custom-Made versus Pre-Fabricated (Off-the-Shelf) Orthoses

A pre-fabricated (off-the-shelf) orthosis is one that is manufactured in quantity without a specific patient in mind.  A pre-fabricated orthosis may be trimmed, bent, molded (with or without heat), or otherwise modified for use by a specific patient (i.e., custom-fitted).  An orthosis that is assembled from pre-fabricated components is considered pre-fabricated.  Any orthosis that does not meet the definition of a custom-fabricated (custom-made) orthosis is considered pre-fabricated.

A custom-fabricated (custom-made) orthosis is one that is individually made for a specific patient starting with basic materials including, but not limited to, plastic, metal, leather, or cloth in the form of sheets, bars, etc.  It involves substantial work such as cutting, bending, molding, sewing, etc.  It may involve the incorporation of some pre-fabricated components.  It involves more than trimming, bending, or making other modifications to a substantially pre-fabricated item.  A molded-to-patient-model orthosis is a particular type of custom-fabricated orthosis in which an impression of the specific body part is made (by means of a plaster cast, CAD-CAM technology, etc.) and this impression is then used to make a positive model (of plaster or other material) of the body part.  The orthosis is then molded on this positive model.

Ankle Orthotics

Ankle orthotics may potentially be useful after an acute ankle injury (acute ankle sprain (ligament injury) or fracture), for rehabilitation, to prevent ankle re-injury, and for chronically unstable ankles.  Whether a specific ankle orthotic is effective depends on the particular indication for its use.

Treatment after acute injury: The ankle begins to swell after injury, and swelling continues to increase for about 3 days following injury.  Significant swelling persists for about 2 weeks following injury.

Rehabilitation: Ankle supports have been used for the first few weeks following injury to prevent re-injury during early return to activity.  After the pain has subsided and the patient can walk without a limp, use of the ankle support is only appropriate during high-risk activities (i.e., especially racquetball, football, and basketball).  Leaving the ankle support on all the time only serves to restrict functional range of motion and encourage psychological dependence.

Prophylaxis: Ankle supports have been used to prevent injury in uninjured individuals and persons with a history of ankle sprain.  There is generally no reason for prophylactic bracing in low-risk activities, such as standing, walking, or climbing stairs.  And it is not clear that prophylactic bracing should be advocated for use during high-risk sports as well, because of prophylactic bracing's cost, inconvenience, and possible detraction from athletic performance.

Chronic instability: Ankle supports are used to stabilize the ankle in patients with chronic instability.  In most instances, they are to be used only during high-risk sports and activities.  It is unusual for ankle supports to be prescribed for use during normal daily activities.

Many types of ankle supports exist as an alternative to ankle taping.  In addition, shoes for some sports (particularly basketball) are available with high tops and built in straps for additional ankle protection.

Recent studies have shown that use of ankle supports during early rehabilitation of acute grade I or grade II ankle sprains (partial ligament rupture) produced results as good as cast immobilization, with more rapid return to activity.

The following is a description of various types of ankle supports, and a summary of the evidence of their effectiveness.  Numerous difficulties arise in interpreting the studies of the various treatments for ankle sprains.  First, most ankle sprains heal well regardless of the form of treatment; thus, almost all treatments produce good results.  It is difficult to measure marginal differences among them.

Second, difficulties arise in comparing different treatment protocols and brands of products.  Research is needed to standardize forms of treatment and to compare the many products on the market.

Third, research has focused on which provide the best mechanical support of the ankle in laboratory stress testing, but it has not been demonstrated that this is the most important factor in predicting clinical outcomes.  It may be that the quality of the proprioceptive (position-sense) feedback from the device is the most important predictor of clinical outcomes.

Taping

A number of studies have supported the use of tape in helping stabilize the ankle and reducing sprains in persons with previous sprains.

The goal of taping is to prevent the ankle ligaments from being stressed to the point of injury.  Taping should limit ankle inversion and eversion but allow functional dorsiflexion and plantarflexion.  There is evidence that ankle taping also helps prevent injury by stimulating proprioceptive (position-sense) nerve fibers, causing the peroneus brevis muscle to be activated just before heel strike.

For treatment of acute injury (beginning within about 3 days following injury), taping may be used to provide support and to help reduce edema (swelling).  Felt or foam pads may be applied under the tape to help reduce edema.

Taping may be used for rehabilitation (i.e., to prevent re-injury during early return to activity).  About 3 days after the injury, swelling subsides, and tape is re-applied to decrease the risk of re-injury.  Using tape to prevent injury, however, is a time-consuming procedure, so it is recommended for early stages of rehabilitation only.  Tape may be applied for the first few weeks after return to activity for rehabilitation of ankle injuries.

Taping may be used prophylactically in persons with or without a prior ankle sprain, although it is not recommended for routine use for this indication.  Although taping probably reduces the rate of ankle injuries, it loses support rapidly with movement and sweating.  This is not as much as a factor in acute sprains, because in which tape is not stressed so much.  For use prophylactically, however, it is not a time- and cost-effective option compared to the alternatives described below.

Taping has also been recommended as a possible treatment for chronic instability, although it is not recommended for routine use in this situation.  With movement and sweating, tape rapidly loses support.  Also, if used permanently, tape becomes expensive.  This approach is probably not as cost- and time-effective as other options described below.

One-inch wide standard tape is used for the foot, and 1½-inch tape for the ankle.  Areas sensitive to blistering must be protected with lubricated gauze sponges.  Special adherent spray may be applied under the tape.  If tape is to be re-applied often, an underwrap is used to prevent chronic skin irritation.

Tape should only be wrapped by a person well-trained in its application, such as a trainer, physician, nurse, or physician assistant.  Improperly applied tape may cause further injury.

Elastic tape has also been studied, and although it provides more compression than non-elastic tape, it loses its restriction of range of motion even more than standard tape.

Tape and wrapping does not meet the durability requirement for covered durable medical equipment, in that it is not reusable and is not "made to withstand prolonged use."  Although Aetna will cover taping or wrapping provided by a healthcare provider in their office, take-home tape and wrapping are not covered.

Elastic Wrapping and Sleeves

Wrapping with elastic bandages is useful in the early stages (about the first 3 days) of ankle sprain to provide compression that reduces swelling.  It is used as an adjunct to ice and elevation.  It needs to be changed often to monitor the skin.  Wrapping has not been proven to be useful for other indications: prevention of re-injury, prophylactic use, and use for chronic ankle instability.  This is because wrapping provides little or no support during activity.

Elastic ankle sleeves that are pulled over the foot like open-ended socks offer no value as supports.  They may, however, enhance proprioception.  They may also provide even compression to reduce ankle edema.  Thus, they have been shown to be useful only in treating an acute ankle sprain (i.e., within about 3 days after injury).  Like elastic wrapping, elastic ankle sleeves have not been proven to be useful for rehabilitation, prophylaxis, or use in chronically unstable ankles.

Certain manufacturers, e.g., Stromgen, combine the comfort of even compression by using Spandex, elastic, and Velcro strap combinations to restrict eversion, and inversion.  They have been used primarily for prophylaxis.

Bracing

Like taping, bracing can be used in an acute injury, during rehabilitation to prevent re-injury, prophylactically, and in chronically unstable ankles.  Braces come in 3 main types: casts, lace-up wraps, and plastic orthoses.  Casts can be either semi-rigid or rigid; lace-up braces and plastic orthoses are considered semi-rigid.

Braces have been shown to have several advantages over taping.  They can be used by persons who do not have access to a person skilled in taping techniques.  In some cases, they can be more cost-effective than taping.  But some braces may migrate during vigorous movement because of the lack of adhesion to skin.  This movement may cause the brace to fail to provide support.  But tape adhesion or straps to reduce migration may help.  During wear-and-tear, Velcro fasteners tend to fail and release, straps or buckles break, and elastic stretches out.  Off-the-shelf braces may not fit persons who are too tall, are obese, or deformed.  Custom-made braces are available, but are generally more expensive.

Rigid Plaster Casts

Rigid plaster casting, once a common treatment for acute ankle sprains, has now been generally abandoned for this use.  Plaster casting continues to be used in foot and ankle fractures.

Compared with taping, rigid plaster casting has been shown to increase the time to return to activity and has not been shown to produce a better outcome, even in patients with grade III ankle sprains (complete rupture of a ligament).

Still, rigid casting is an option to consider for the early post-operative phase or in cases of gross ankle instability.  When acute swelling subsides, the cast should be replaced with a better fitting one.  It should be replaced with semi-rigid bracing as soon as possible, usually within 1 to 2 weeks.

Rigid casting is not used to prevent re-injury during rehabilitation, for prophylaxis, or for chronic instability.

Soft (Semi-Rigid) Casts

Semi-rigid casting is done with a wrap that hardens somewhat after application but does not become completely rigid.  The Una (Unna's) boot (Graham Field, Inc., Hauppage, NY) is a semi-rigid cast that consists of a gauze bandage that contains glycerin and gelatin and is applied over a felt bone around the anklebone (the medial malleolus).  In an acute sprain, it provides some support and compression.  Ice is commonly applied around the boot, but no studies have demonstrated adequate tissue cooling with this technique.  In the treatment of acute ankle injuries, semi-rigid casts have not been shown to be more effective than tape.  Semi-rigid casting does not offer enough support to be used to prevent injury during rehabilitation, for prophylaxis, or for chronic instability.

Lace-Up Braces

Lace-up braces have been proven to be as effective as tape at restricting ankle range of motion, and unlike tape, lace-ups do not tend to lose their supportive ability during activity.  Lace-up braces are a cost-effective alternative to taping.  They are safe, easy to apply, and reusable.  They are not of much value in the acute stage of injury because they do not provide good uniform compression.  They are probably of some value in preventing re-injury during rehabilitation, for prophylactic use, and for use in patients with chronic ankle instability.

Air-Stirrups

The air-stirrup is a pre-fabricated semi-rigid orthosis.  The largest-selling brand is the Aircast air-stirrup ankle brace (Aircast, Summit, NJ), which is composed of a rigid outer plastic shell that fits up both sides of the leg and is connected under the heel.  It is lined with inner air bags and is attached to the leg with Velcro.  As with lace-up ankle supports, some clinicians combine use of the air-stirrup with taping.  The air-stirrup is an off-the-shelf device that does not require custom fitting.  It can be worn under regular shoes.

The air-stirrup decreases inversion and eversion, and protects the already injured ligament and soft tissues from re-injury, thereby decreasing rehabilitation time.  The pressure in the air-stirrup increases when weight-bearing, which is thought to provide intermittent compression during walking that aids in the milking out of edematous fluid.  The air-stirrup can also be readjusted to allow total contact fitting while swelling is fluctuating.

The air-stirrup can be used after acute ankle sprains and in the early stages of rehabilitation to prevent recurrent sprain.  It can also be used after rigid casting and for treatment of some fractures.  There is currently insufficient evidence for their use for prophylaxis or in chronic instability, although some newer variations of the splint have been designed for this purpose.

Other Semi-Rigid Orthoses

Other semi-rigid orthoses have not been studied adequately to make accurate comparisons with taping or with air-stirrups.  These include the following:

• DonJoy Ankle Ligament Protector (DonJoy, Carlsbad, CA) is a plastic brace that seems to restrict range of motion as well as the air-stirrup and possibly better than tape, although no head-to-head comparisons have been published.
• The Active Ankle (Active Ankle Systems, Louisville, KY) has a stirrup and air cell liner with a hinged ankle may also be useful.
• The Malleoloc (Bauerfiend USA, Kennesaw, GA) is a stabilizing ankle orthosis that uses a wrap-around ankle brace in conjunction with Velcro strapping.  Although it shows promise, definitive proof if its effectiveness is not yet available.

Other Ankle-Stabilizing Orthoses

• Non-Elastic Cloth Wrapping: Non-elastic cloth wrap (also known as the Louisiana heel lock) has been applied over socks to prevent ankle injury.  The advantage of this system is that the wrap can be washed or reused, thus reducing cost.  Cloth wrapping may improve position-sense, but it appears to offer less benefit than taping.  Its use in ankle injuries has not been adequately studied.
• Nylon and Nylon/Elastic Wrapping: Nylon or Nylon/Elastic heel wraps to be placed over socks may also improve position sense, but like non-elastic cloth wrapping, their use in ankle injuries has not been adequately studied.
• Orthoplast Stirrup: The orthoplast stirrup is a strip of thermoplastic material custom-fitted to run under the heel and up both sides of the leg.  The ankle bones (malleoli) and other bony prominences are covered with foam padding, and the stirrup is fitted with an elastic bandage.

Orthoplast is a low-temperature thermoplastic that becomes pliable when submerged in hot water.  It is applied directly to the patient and molded evenly around the ankle.  The fabrication is simple enough to be carried out in the office or clinic.

The orthoplast stirrup has been successfully used to treat ankle sprains, but because it is relatively hard, it does not adapt to reduction in swelling.  It has not been shown to decrease inversion range of motion more than tape, and is most commonly used in the acute or early rehabilitative stages.  Orthoplast deteriorates with long-term use, limiting its usefulness in prophylaxis and for chronic ankle sprains.

Stabilizing Shoes

Several shoe designs have been used for prevention and treatment of ankle sprains.

• Acute injury, rehabilitation, and chronic instability: The use of ankle-stabilizing shoes, such as the Kunzli line of shoes (Swiss Balance, Santa Monica, CA), to treat ankle sprain and to prevent re-injury have not been studied adequately to date.
• Prophylaxis: High-topped shoes have been shown to increase ankle stiffness in sports.  However, the advantage of high-topped shoes over low-topped shoes in prophylaxis has been shown to be relatively small.  The prophylactic benefits of various shoe types in sports have not been adequately investigated.

Cast-Braces

A number of hinged polypropylene cast braces have been used in the treatment of ankle sprains.  These involve have a foot section with heel stabilizer, a lateral ankle extension, and an articulating ankle joint joining the two.  An example is the Sarmiento cast brace, which is removable and fits in the patient's shoe.  They were designed primarily for long-term use in athletes who suffer from recurrent ankle sprains (i.e., prophylaxis and chronic instability).

Cast-braces require custom fitting by an orthotist for proper impression, fabrication, and fitting.  Fitting of a fresh ankle sprain with a cast-brace is usually not recommended because changes in swelling of the ankle during the initial recovery phase will compromise the cast-brace's fit.

Although these cast-braces have reportedly given good results in the treatment of ankle sprains, they are cumbersome, expensive, and have not been shown to offer any benefits over other forms of treatment.

The Boston Ankle System

The Boston Ankle System (Physical Support Systems, Boston, MA) is a custom-fitted ankle stabilizer.  The Boston Ankle System is made of polypropylene and requires an exact impression.  The services of an orthotist are often required for fine adjustment and accurate fitting.

Ice Pack with Air-Stirrup

The Cryo/Strap (Aircast, Summit, NJ) ice pack with air-stirrup uses a U-pad for compression of the soft tissue around the ankle.  The pad contains a liquid that can be frozen and is held in place by an elastic strap.  A modified air-stirrup is worn over this device.  This system has been shown to provide uniform compression and to decrease skin temperature for up to 90 mins.  It has not been shown, however, to improve long-term outcomes.

Ankle-Foot Orthoses (AFOs) and Knee-Ankle-Foot Orthoses (KAFOs)

Ankle-foot orthoses (AFOs) extend well above the ankle (usually to near the top of the calf) and are fastened around the lower leg above the ankle.  These features distinguish them from foot orthotics, which are shoe inserts that do not extend above the ankle.

Below the knee, the components of a KAFO are the same as those of an AFO.  However, the KAFO extends to the knee joint and thigh.

A non-ambulatory ankle-foot orthosis may be either an ankle contracture splint or a foot drop splint.

Figueiredo et al (2008) performed a literature review evaluating the quality of current research on the influence of AFO on gait in children with cerebral palsy (CP).  Two between-group and 18 within-group studies met the inclusion criteria indicating a low level of evidence.  Between-group studies each scored "4" on the PEDro Scale, and 17 within-group studies scored "3" and 1 scored "2", indicating low-quality.  Standard terminology for AFO was not used and only 6 studies described functional status using appropriate instruments.  The authors concluded that studies using high-quality methods are still needed to support evidence-based decisions regarding the use of AFO for this population.

The Intrepid Dynamic Exoskeleton Orthosis (IDEO) is a custom molded energy-storing AFO that was reportedly developed for individuals who have suffered massive tissue, nerve and bone damage to supposedly return capabilities to the injured ankle. Purportedly, the individual can return to a high level of activity, such as running. The IDEO device is molded out of lightweight black carbon that includes a foot plate and a strut that runs up the back of the calf to a cuff that is situated just below the knee. Reportedly, when force is applied to the foot plate, the strut bends. As the individual steps down, it bends the foot plate, transferring energy forward.

Microprocessor-Controlled KAFOs

Microprocessor activated mobility devices combine electronic components with specialized orthotic braces to reportedly provide assistance in walking to individuals with back injuries or leg muscle weakness. Examples of microprocessor activated devices include, but may not be limited to, the C-Brace Orthotronic Mobility System or the Sensor Walk Stance Control knee brace.

Irby et al (2005) noted that individuals with weak or absent quadriceps who wish to walk independently were prescribed KAFOs.  New stance control orthosis (SCO) designs automatically release the knee to allow swing phase flexion and extension while still locking the joint during stance.  A total of 21 subjects were fitted unilaterally with the Dynamic Knee Brace System (DKBS), a non-commercial SCO – 13 were experienced KAFO users (average of 28 +/- 18 years of experience) while 8 were novice users.  Novice users demonstrated increased velocity (55 versus 71 cm/sec, p = 0.048) and cadence (77 versus 85 steps/min, p < 0.05) when using the DKBS over the traditional locked KAFO.  Experienced KAFO users tended to have reduced velocity and cadence measures when using the SCO (p < 0.10).  Knee range of motion was significantly greater for the novice group than for the experienced group (55.2 +/- 4.8 versus 42.6 +/- 3.8 degrees, p = 0.05).  Peak knee extension moments tended to be greater for the experienced group (0.29 +/- 0.21 versus 0.087 +/- 0.047 Nm/kg, p = 0.09).  This report described gait changes during the introductory phase of DKBS adoption.  Experienced KAFO users undoubtedly had ingrained gait patterns designed to compensate for walking with a standard locked KAFO.  These patterns may have limited the ability of those users from taking full and immediate advantage of the SCO capabilities.  Also, alternate SCO systems may engender different results.  The authors concluded that comparison studies and longer term field studies are needed to clarify benefits of the various bracing options.

Zissimopoulos et al (2007) noted that users of traditional KAFOs walk with either locked or unlocked knee joints depending on the level of stability required.  Some users may benefit from new stance-control KAFOs that prevent stance-phase knee flexion but allow swing-phase flexion.  These researchrs collected data from 9 non-disabled adults who walked with KAFOs that incorporated the Horton Stance-Control Orthotic Knee Joint (SCOKJ) in the locked, unlocked, and auto (which provides knee stability during stance phase and knee flexion during swing phase) modes to investigate the biomechanical and energetic effects of stance-control orthoses.  Studying non-disabled subjects allowed these researchers to analyze the effects of stance-control orthoses in a homogenous population.  In general, gait kinematics for the auto and unlocked modes were more similar than for the auto and locked modes.  Despite the elimination of hip hiking in the auto mode, oxygen cost was not different between the auto and locked modes (p > 0.99).  The SCOKJ allowed non-disabled subjects to walk with a more normal gait pattern; however, future research should explore the effect of stance-control orthoses on persons with gait pathology.

Davis et al (2010) stated that Stance Control knee-ankle foot orthoses (SCO) differ from their traditional locked knee counterparts by allowing free knee flexion during swing while providing stability during stance.  It is widely accepted that free knee flexion during swing normalizes gait and therefore improves walking speed and reduces the energy requirements of walking.  Limited research has been carried out to evaluate the benefits of SCOs when compared to locked KAFOs.  The purpose of this study was to evaluate the effectiveness of SCOs used for patients with lower limb pathology.  Energy expenditure and walking velocity were measured in 10 subjects using an orthosis incorporating a SCOKJ.  A GAITRite walkway was used to measure temporo-spatial gait characteristics.  A Cosmed K4b2 portable metabolic system was used to measure energy expenditure and heart rate during walking.  Two conditions were tested:

1. walking with stance control active (stance control) and
2. walking with the knee joint locked.

Ten subjects completed the GAITRite testing; 9 subjects completed the Cosmed testing.  Walking velocity was significantly increased in the stance control condition (p < 0.001).  There was no difference in the energy cost of walking (p = 0.515) or physiological cost index (p = 0.093) between conditions.  The authors concluded that these findings supported previous evidence that stance control knee-ankle foot orthoses increase walking velocity compared to locked knee devices.  However, the stance control condition did not decrease energy expenditure during walking.

In a randomized, cross-over study, Deems-Dluhy and colleagues (2021) examined the potential of a microprocessor swing and stance controlled knee-ankle-foot orthosis (MPO) to improve balance, functional mobility, and QOL in individuals with lower-extremity impairments as compared to a SCO and conventional KAFO over a use-period of a month.  Subjects included community-dwelling adults (n = 18) who actively used a unilateral KAFO or SCO for impairments due to neurologic or neuromuscular disease, orthopedic disease, or trauma.  They were trained to acclimate and use SCO and MPO.  Main outcome measures included the 6MWT, 10-m walk test, Berg Balance Scale (BBS), functional gait assessment (FGA), hill assessment index, stair assessment index (SAI), Five Times Sit to Stand Test, cross-walk test, Modified Falls Efficacy Scale, Orthotic and Prosthetic User's Survey (OPUS), and World Health Organization QOL (WHQOL)-BREF Scale.  Significant changes were observed in subjects' self-selected gait speed (p = 0.023), BBS (p = 0.01), FGA (p = 0.002), and SAI (p < 0.001) between baseline and post-MPO assessment.  Similar significant differences were observed when comparing post-MPO with post-SCO data.  During the 6MWT, persons using the MPO walked significantly longer (p = 0.013) than when using their baseline device.  Subjects reported higher QOL scores in the OPUS (p = 0.02) and physical health domain of the WHOQOL-BREF (p = 0.037) after using the MPO.  Subjects reported fewer falls when wearing the MPO (5) versus an SCO (38) or locked KAFO (15).  The authors concluded that MPO may contribute to improved QOL and health status of persons with lower-extremity impairments by providing the ability to have better walking speed, endurance, and functional balance.

Ankle Contraction Splints / Static Dynamic AFOs

According to Medicare Durable Medical Equipment Carrier Guidelines, a static-dynamic AFO is a pre-fabricated AFO that has all of the following characteristics:

1. Applies a dorsiflexion force to the ankle , and
2. Designed to accommodate either plantar fasciitis or an ankle with a plantar flexion contracture up to 45°, and
3. Has a soft interface, and
4. Used by a patient who is minimally ambulatory or non-ambulatory.

Ankle flexion contracture is a condition in which there is shortening of the muscles and/or tendons that plantarflex the ankle with the resulting inability to bring the ankle to 0 degrees by passive range of motion.  (0 degrees ankle position is when the foot is perpendicular to the lower leg.)

Foot Drop Splint

A foot drop splint/recumbent positioning device is a pre-fabricated AFO, which has all of the following characteristics:

1. Designed to maintain the foot at a fixed position of 0° (i.e., perpendicular to the lower leg), and
2. Has a soft interface, and
3. Not designed to accommodate an ankle with a plantar flexion contracture, and
4. Used by a patient who is non-ambulatory.

Foot drop is a condition in which there is weakness and/or lack of use of the muscles that dorsiflex the ankle but there is the ability to bring the ankle to 0 degrees by passive range of motion.

Foot and Ankle Orthoses for Rheumatoid Arthritis

Hennessy and colleagues (2012) evaluated the evidence for the effectiveness of custom orthoses for the foot and ankle in rheumatoid arthritis.  Studies were identified in appropriate electronic databases (from 1950 to March 2011).  The search term "rheumatoid arthritis" with "foot" and "ankle" and related terms were used in conjunction with "orthoses" and synonyms.  Included studies were quantitative longitudinal studies and included randomized controlled trials (RCTs), case-control trials, cohort studies, and case series studies.  All outcome measures were investigated.  Quality assessment was conducted using the Cochrane Collaboration criteria with additional criteria for sample population representativeness, quality of statistical analysis, and compliant intervention use and presence of cointerventions.  Meta-analyses were conducted for outcome domains with multiple RCTs.  Qualitative data synthesis was conducted for the remaining outcome domains.  Levels of evidence were then assigned to each outcome measure.  The inclusion criteria were met by 17 studies – 2 studies had high-quality for internal validity and 3 studies had high-quality for external validity.  No study had high-quality for both internal and external validity.  Six outcome domains were identified.  There was weak evidence for custom orthoses reducing pain and forefoot plantar pressures.  Evidence was inconclusive for foot function, walking speed, gait parameters, and reducing hallux abductovalgus angle progression.  The authors concluded that custom orthoses may be beneficial in reducing pain and elevated forefoot plantar pressures in the rheumatoid foot and ankle.  However, they stated that more definitive research is needed in this area.

AFOs and KAFOs for Knee Instability Related to Neuromuscular and Central Nervous System Disorders

In a pilot study, Arazpour and co-workers (2016) determined the effect of a powered KAFO on the physiological cost index, walking speed and the distance walked in people with poliomyelitis compared to when walking with a KAFO with drop lock knee joints.  A total of 7 subjects with poliomyelitis volunteered for the study and undertook gait analysis with both types of KAFOs.  Walking with the powered KAFO significantly reduced walking speed (p = 0.015) and the distance walked (p = 0.004), and also, it did not improve physiological cost index values (p = 0.009) compared to walking with the locked KAFO.  The authors concluded that using a powered KAFO did not significantly improve any of the primary outcome measures during walking for poliomyelitis subjects.  They stated that this powered KAFO design did not improve the physiological cost index of walking for people with poliomyelitis when compared to walking with a KAFO with drop lock knee joints.  This may have been due to the short training period used or the bulky design and additional weight of the powered orthosis; further research is therefore warranted.

In a Health Technology Assessment on "Orthotic management of instability of the knee related to neuromuscular and central nervous system disorders: systematic review, qualitative study, survey and costing analysis", O’Connor and associates (2016) concluded that various types of orthoses (KAFOs [mainly carbon fiber], stance control KAFO and hip KAFOs) were used in the United Kingdom Nation Health Service to manage patients with neuromuscular disorder (NMD)/central nervous system (CNS) conditions (e.g., inclusion body myositis, post-polio syndrome, post-stroke, and spinal cord injury [SCI]) and knee instability, both custom-made and pre-fabricated, of variable cost.  They stated that evidence on the effectiveness of the orthoses was limited, especially in relation to the outcomes that were important to orthoses users.

Kobayashi and colleagues (2016) noted that genu recurvatum (knee hyperextension) is a common issue for individuals post-stroke; AFOs are used to improve genu recurvatum, but evidence is limited concerning their effectiveness.  These researchers examined the effect of changing the plantarflexion resistance of an articulated AFO on genu recurvatum in patients post-stroke.  Gait analysis was performed on 6 individuals post-stroke with genu recurvatum using an articulated AFO whose plantarflexion resistance was adjustable at 4 levels.  Gait data were collected using a Bertec split-belt instrumented treadmill in a three-dimensional (3D) motion analysis laboratory.  Gait parameters were extracted and plotted for each subject under the 4 plantarflexion resistance conditions of the AFO.  Gait parameters included peak ankle plantarflexion angle, peak ankle dorsiflexion moment, peak knee extension angle and peak knee flexion moment.  A non-parametric Friedman test was performed followed by a post-hoc Wilcoxon Signed-Rank test for statistical analyses.  All the gait parameters demonstrated statistically significant differences among the 4 resistance conditions of the AFO.  Increasing the amount of plantarflexion resistance of the AFO generally reduced genu recurvatum in all subjects.  However, individual analyses showed that the responses to the changes in the plantarflexion resistance of the AFO were not necessarily linear, and appeared unique to each subject.  The authors concluded that plantarflexion resistance of an articulated AFO should be adjusted to improve genu recurvatum in patients post-stroke; and future studies should examine what clinical factors would influence the individual differences.

In a pilot study, Kobayashi and associates (2016) studied the mechanical properties of a novel articulated AFO with adjustable plantarflexion resistance, dorsiflexion resistance and alignment, and its effect on ankle and knee joint kinematics and kinetics in an individual post-stroke during gait.  The mechanical properties of the AFO were quantified.  Gait analysis was performed using a 3D motion capture system with a split-belt instrumented treadmill under 12 different settings of the mechanical properties of the AFO [i.e., 4 plantarflexion resistances (P1<P4), 4 dorsiflexion resistances (D1<D4), 4 initial alignments (A1<A4)].  The AFO demonstrated systematic changes in moment-angle relationship in response to changes in AFO joint settings.  The gait analysis demonstrated that the ankle and knee angle and moment were responsive to changes in the AFO joint settings.  Mean ankle angle at initial contact changed from -0.86° (P1) to 0.91° (P4) and from -1.48° (A1) to 4.45° (A4), while mean peak dorsiflexion angle changed from 12.01° (D1) to 6.40° (D4) at mid-stance.  The authors concluded that the novel articulated AFO appeared effective in influencing lower-limb joint kinematics and kinetics of gait in the individual post-stroke.  The findings of this pilot study need to be further investigated.

In a RCT, Nikamp and co-workers (2017) examined the 6-month clinical effects of providing AFOs at different moments (early or delayed) in (sub)acute stroke; this was a follow-up to a published trial.  Participants were unilateral hemiparetic stroke subjects maximal 6 weeks post-stroke with indication for AFO use.  Subjects were randomly assigned to early (at inclusion; week 1) or delayed provision (8 weeks later; week 9).  Functional tests assessing balance and mobility were performed bi-weekly for 17 weeks and at week 26.  A total of 33 subjects were randomized.  No differences at week 26 were found between both groups for any of the outcome measures.  However, results suggested that early provision led to better outcomes in the first 11 to 13 weeks. Berg Balance Scale (p = 0.006), Functional Ambulation Categories (p = 0.033) and 6-minute walk test (6MWT; p < 0.001) showed significantly different patterns over time.  Clinically relevant but statistically non-significant differences of 4 to 10 weeks in reaching independent walking with higher balance levels were found, favoring early provision.  The authors concluded that no 6-month differences in functional outcomes of providing AFOs at different moments in the early rehabilitation after stroke were found.  Moreover, they stated that these findings suggested that there was a period of 11 to 13 weeks in which early provision may be beneficial, possibly resulting in early independent and safe walking.  However, they noted that this study was under-powered; further investigation including larger numbers of subjects is needed.

In a systematic review, McDaid and colleagues (2017) evaluated the effectiveness of orthotic devices for the management of instability of the knee in adults with a NMD or CNS disorder.  Interventions employed were orthoses (e.g., AFOs, KAFOs, and knee orthoses or mixed design with no restrictions in design or material) with the clinical aim of controlling knee instability.  Outcomes included condition-specific or generic patient-reported measures assessing function, disability, independence, activities of daily living (ADLs), quality of life (QOL) or psychosocial outcomes; pain; walking ability; functional assessments; biomechanical analysis; adverse effects; usage; patient satisfaction and the acceptability of a device; as well as resource utilization data.  A total of 21 studies including 478 patients were included.  Orthotic devices were evaluated in patients with inclusion body myositis, post-polio syndrome, post-stroke syndrome, and SCI).  The review included 2 RCTs, 3 non-RCTs and 16 case series.  Most were small, single-center studies with only 6 of 21 following patients for 1 year or longer.  They met between 1 and 5 of 9 quality criteria and reported methods and results poorly.  They mainly assessed outcomes related to gait analysis and energy consumption with limited use of standardized, validated, patient-reported outcome measures.  There was an absence of evidence on outcomes of direct importance to patients such as reduction in pain and falls.  The authors concluded that there is a need for high-quality research, especially RCTs, on the effectiveness of AFOs, KAFOs and other orthotic devices for managing knee instability related to NMD and CNS conditions.  They stated that this research should address outcomes that are important to patients; and there may also be value in developing a national registry.

In a systematic review, Daryabor and associates (2018) evaluated the efficacy of different designs of AFOs and comparison between them on the gait parameters of individuals with hemiplegic stroke.  The search strategy was based on the population intervention comparison outcome (PICO) method.  A search was performed in PubMed, ISI Web of Knowledge, Scopus, Science Direct, and Google Scholar databases.  A total of 27 articles were found for the final evaluation.  All types of AFOs had positive effects on ankle kinematic in the first rocker and swing phases, but not on knee kinematics in the swing phase, hip kinematics or the third rocker function.  All trials, except 2, assessed immediate or short-term effects only.  The articulated passive AFO compared with the non-articulated passive AFO had better effects on some aspects of the gait of patients with hemiplegia following stroke, more investigations are needed in this regard though.  The authors concluded that an AFO can immediately improve the dropped foot in the stance and swing phases.  Moreover, they stated that the effects of long-term usage and comparison among the different types of AFOs need to be evaluated.

Adjustable Stance-Control KAFO for Pediatric Population

Gerez and Vieira (2019) noted that conventional KAFOs are generally prescribed for children with lower limb muscle weakness and joint instabilities. The main function of KAFOs is to provide stability during gait by locking the knee in full extension.  Moreover, walking with the knee joint in a fully extended position requires excessive energy consumption, leading to early fatigue and inducing non-physiological gait patterns.  A new generation of KAFOs was developed to allow free knee flexion during the swing-phase and to lock the knee joint during the stance-phase to provide the required stability. These are commonly labeled as stance-control KAFOs (SCKAFOs). However, commercial SCKAFOs are not available for the pediatric population. Especially in early ages, children must frequently replace the orthosis due to their growth.  The authors stated that the proposed design presented a solution for a SCKAFO with adjustable length adaptable to children's dimensions ranging from 2 to 6 years of age.

Reciprocating Gait Orthosis (RGO) or Hip KAFO for Patients with Spinal Cord Injury

Barati and colleagues (2021) noted that the quality of life QOL for patients with spinal cord injuries (SCI) is lower than that for healthy individuals. The main purpose of prescribing orthoses for these individuals is to improve their mobility and QOL. The hip knee ankle foot orthosis (HKAFO) has been the conventional choice for such patients, while the reciprocating gait orthosis (RGO) is a more contemporary option. Although the impact of these 2 types of orthoses on the biomechanics of walking has been previously evaluated in patients with SCI, there has been no specific comparison of their relative effects on QOL. These researchers examined the Sickness Impact Profile (SIP-68) QOL questionnaire's total score and its sub-scores in patients with SCIs wearing either RGOs or HKAFOs. This trial included 22 subjects (11 wearing RGOs and 11 wearing HKAFOs); QOL scores were assessed in each group of patients using the total and sub-scores from the SIP-68 questionnaire. There were no significant differences in the total SIP-68 scores between the RGO and HKAFO groups (p = 0.57).  However, emotional stability and emotional independence sub-scores were significantly lower for the RGO users than for the HKAFO users (p = 0.03 and p = 0.01), respectively.  The authors concluded that based upon this preliminary study, subjects wearing RGOs or HKAFOs had similar QOL scores.  However, those wearing RGOs may experience better emotional stability, communication, and emotional independence. This preliminary study did not provide definite conclusions since a large RCT is needed to compare the effects of these orthoses on the QOL scores in patients with SCIs.  These researchers stated that the principal objective of this study was to shed light on the question that does the biomechanical superiority of the RGO to the HKAFO leads to better QOL in SCI subjects who are using RGO.  Regarding the fact that the primary goal of rehabilitation of people with SCI is to improve their QOL, it appeared that the more complicated newer orthosis (RGO) has no difference with the older type (HKAFO) in achieving the rehabilitation goals.  They stated that more studies are needed to answer this important question.  These investigators stated that according to these findings, it appeared to be more appropriate to prescribe RGO for male subjects with higher body weight.

Ankle-Foot Orthoses for Children with Autism Spectrum Disorder Who Toe Walk

In a proof of concept study, Barkocy and colleagues (2021) examined the effectiveness of serial casting (SC) and AFOs in children with autism spectrum disorder (Ch-ASD) who toe walk (TW).  Data collected determined effects of SC, followed by AFO intervention on ankle dorsiflexion (A-DF) passive range of motion (ROM) and kinematics, and parent-reported functional outcomes for children with ASD who TW and have limited A-DF passive ROM.  The 5 subjects increased passive ROM with SC, except for 1 subject's left ankle; 2 of 4 subjects had near typical A-DF kinematic patterns following SC.  The 5 subjects improved A-DF during walking following 6 months of AFO use.  The authors concluded that serial casting increased A-DF ROM and kinematics during walking.  These investigators stated that consistent AFO use for walking training improved function and reduced toe walking.  They stated that serial casting followed by AFOs is a potential intervention for children with ASD who TW.

Ankle-Foot Orthoses for the Treatment of Osteoarthritis of the Knee

In a single-center, block-randomized, cross-over, controlled trial, Schwarze and colleagues (2021) compared biomechanical and clinical outcome of laterally wedged insoles (LWI) and an AFO in patients with medial knee osteoarthritis (OA; n = 39).  Patients started with either LWI or AFO, determined randomly, and 6 weeks later changed to the alternative.  Change in the 1st maximum of external knee adduction moment (eKAM) was evaluated with gait analysis.  Additional outcomes were other kinetic and kinematic changes and the patient-reported outcomes EQ-5D-5L, Oxford Knee Score (OKS), American Knee Society Clinical Rating System (AKSS), Hannover Functional Ability Questionnaire - Osteoarthritis and knee pain.  Mean age (SD) of the study population was 58 (8) years, mean body mass index (BMI) 30 (5).   Both aids significantly improved OKS (LWI; p = 0.003, AFO; p = 0.001), AKSS Knee Score (LWI; p = 0.01, AFO; p = 0.004) and EQ-5D-5L Index (LWI; p = 0.001, AFO; p = 0.002).  AFO reduced the 1st maximum of eKAM by 18 % (p < 0.001).  The LWI reduced both maxima by 6 % (p = 0.02, p = 0.03).  Both AFO and LWI reduced the knee adduction angular impulse (KAAI) by 11 % (p < 0.001) and 5 % (p = 0.05), respectively.  The eKAM (1st maximum) and KAAI reduction was significantly larger with AFO than with LWI (p = 0.001, p = 0.004).  The authors concluded that the findings of this study showed that LWIs and AFOs did not differ in their clinical improvements after 6 weeks of use.  Biomechanically, the AFO causes a significantly larger reduction of medial knee load than the LWI.  As this biomechanical difference was not reflected in patient-reported outcomes, the link between biomechanical and clinical changes produced by the aids remains unclear.  A clinically relevant improvement of pain and functional outcomes cannot be generally assumed for all patients.  This makes uncritical use of the devices questionable.  However, since the majority of patients experienced a pain reduction with both aids, these investigators consider a therapy attempt justified in mild-to-moderate knee OA.  Moreover, these researchers stated that the heterogeneous response to both devices highlighted a need for research to determine patient characteristics that better predict which patients fully harness the benefits of the biomechanical changes.  Regarding the promising biomechanical effects of the AFO, insights on the long-term influence on disease progression would prove to be valuable.

Ankle-Foot Orthoses for Post-Stroke Rehabilitation

In a meta-analysis, choo and Chang (2021) examined the effectiveness of AFO use in improving gait biomechanical parameters such as walking speed, mobility, and kinematics in patients with stroke with gait disturbance.  These investigators searched the Medline (Medical Literature Analysis and Retrieval System Online), CINAHL (Cumulative Index to Nursing and Allied Health Literature), Cochrane, Embase, and Scopus databases and retrieved studies published until June 2021.  Experimental and prospective studies were included that examined biomechanics or kinematic parameters with or without AFO in patients with stroke.  They analyzed gait biomechanical parameters, including walking speed, mobility, balance, and kinematic variables, in studies involving patients with and without AFO use.  The criteria of the Cochrane Handbook for Systematic Reviews of Interventions were used to evaluate the methodological quality of the studies, and the level of evidence was evaluated using the Research Pyramid model.  Funnel plot analysis and Egger's test were conducted to confirm publication bias.  A total of 19 studies including 434 subjects that reported on the immediate or short-term effectiveness of AFO use were included in the analysis.  Significant improvements in walking speed (standardized mean difference [SMD], 0.50; 95 % CI: 0.34 to 0.66; p < 0.00001; I2 = 0 %), cadence (SMD, 0.42; 95 % CI: 0.22 to 0.62; p < 0.0001; I2 = 0 %), step length (SMD, 0.41; 95 % CI: 0.18 to 0.63; p = 0.0003; I2 = 2 %), stride length (SMD, 0.43; 95 % CI: 0.15 to 0.71; p = 0.003; I2 = 7 %), Timed up-and-go test (SMD, - 0.30; 95 % CI: - 0.54 to - 0.07; p = 0.01; I2 = 0 %), functional ambulation category (FAC) score (SMD, 1.61; 95 % CI: 1.19 to 2.02; p < 0.00001; I2 = 0 %), ankle sagittal plane angle at initial contact (SMD, 0.66; 95 % CI: 0.34 to 0.98; p < 0.0001; I2 = 0 %), and knee sagittal plane angle at toe-off (SMD, 0.39; 95 % CI: 0.04 to 0.73; p = 0.03; I2 = 46 %) were observed when the patients wore AFOs.  Stride time, body sway, and hip sagittal plane angle at toe-off were not significantly improved (p = 0.74, p = 0.07, p = 0.07, respectively).  Among these results, the FAC score showed the most significant improvement, and stride time showed the lowest improvement.  The authors concluded that AFO improved walking speed, cadence, step length, and stride length, especially in patients with stroke; AFO is considered beneficial in enhancing gait stability and ambulatory ability.  Moreover, these researchers stated that in the future, a study should be carried out in which confounding variables such as the individual physical ability of the subjects and intervention in rehabilitation programs other than AFO are controlled, and more subjects should be included than in the current meta-analysis.

These investigators stated that this study had several drawbacks.  First, the physical status, such as the degree of motor weakness, sensory deficits, and spasticity, of the included patients was not considered in each study.  Second, the effects of rehabilitation or training other than the use of AFOs were not considered.  Third, as the number of patients included in each study was small, this meta-analysis included a relatively small number of subjects.  Fourth, a limited number of databases were searched.  Fifth, the study designs of the included studies were heterogeneous.  Sixth, the study protocol was not registered or published in advance.  

Johnston et al (2021) stated that level of ambulation following stroke is a long-term predictor of participation and disability.  Decreased lower extremity (LE) motor control could impact ambulation and overall mobility.  In a clinical practice guideline (CPG), these investigators provided evidence to guide clinical decision-making for the use of either AFO or functional electrical stimulation (FES) as an intervention to improve body function and structure, activity, and participation as defined by the International Classification of Functioning, Disability and Health (ICF) for individuals with post-stroke hemiplegia with decreased LE motor control.  They carried out a review of literature published through November 2019 across 7 databases for all studies involving stroke and AFO or FES.  Data extracted included time post-stroke, subject characteristics, device types, outcomes assessed, and intervention parameters.  Outcomes were examined upon initial application and after training.  Recommendations were determined on the basis of the strength of the evidence and the potential benefits, harm, risks, or costs of providing AFO or FES.  A total of 122 meta-analyses, systematic reviews, RCTs, and cohort studies were included.  Strong evidence exists that AFO and FES could each increased gait speed, mobility, and dynamic balance.  Moderate evidence exists that AFO and FES increased QOL, walking endurance, and muscle activation, and weak evidence exists for improving gait kinematics.  AFO or FES should not be used to decrease plantar-flexor spasticity.  Studies that directly compared AFO and FES did not indicate overall superiority of one over the other; however, evidence suggested that AFO may lead to more compensatory effects while FES may lead to more therapeutic effects.  Due to the potential for gains at any phase post-stroke, the most appropriate device for an individual may change, and reassessments should be completed to ensure the device was meeting the individual's needs.  The authors concluded that this CPG suggested that AFO and FES both resulted in improvements post-stroke.  Moreover, these researchers stated that future studies should examine timing of provision, device types, intervention duration and delivery, longer term follow-up, responders versus non-responders, and individuals with greater impairments.

The authors stated that the drawbacks of this CPG included that it could not address the effects of one type of AFO over another for the majority of outcomes, as studies used a variety of AFO types and rarely differentiated effects.  The recommendations also did not address the severity of hemiparesis, and most studies included subjects with varied baseline ambulation ability.

Sekiguchi et al (2021) noted that categorization based on quasi-joint stiffness (QJS) may help clinicians select appropriate AFOs.  These researchers classified the gait pattern based on ankle joint stiffness, also called QJS, of the gait in patients after stroke and clarified differences in the type of AFO among 72 patients after stroke.  Hierarchical cluster analysis was employed to classify gait patterns based on QJS at least 1 month before the study, which revealed t3 distinct subgroups (SGs 1, 2, and 3).  The proportion of use of AFOs, articulated AFOs, and non-articulated AFOs were significantly different among SGs 1 to 3.  In SG1, with a higher QJS in the early and middle stance, the proportion of the patients using articulated AFOs was higher, whereas in SG3, with a lower QJS in both stances, the proportion of patients using non-articulated AFOs was higher.  In SG2, with a lower QJS in the early stance and higher QJS in the middle stance, the proportion of patients using AFOs was lower.  The authors concluded that these findings indicated that classification of gait patterns based on QJS in patients after stroke may be helpful in selecting AFO; however, studies large sample sizes are needed to confirm these findings.  Moreover, these researchers stated that future research should collect both kinetic/QJS as well as kinematic data for gait classification.  However, appropriate data (i.e., kinematic parameters, other parameters) for use in gait classification may depend on the purpose for which the gait classification is used.  These investigators stated that a variety of data on gait in stroke patients is needed to determine a gait classification index for appropriate treatment and orthotic selection.  In the present results, the SG1 sample size was small.  The use of 3D motion analysis is limited in terms of resources to measure large amounts of data, which may require the use of wearable sensors or depth sensors that are currently being developed.  Additionally, future research on gait classification, including patients in the subacute phase, should provide valuable information to clarify the recovery process.

The authors stated that this study had several drawbacks.  First, only patients who could walk without any assistance after stroke were recruited.  Patients with a slow gait speed in the previous studies used a 4-point or straight cane when walking.  Furthermore, in comparison to those in the previous studies (0.13 m/s and 0.23 m/s; 0.16 m/s), the gait speed (0.31 m/s) in the SGs that was categorized as slow gait speed in the present study was faster.  The differences in gait function between the present study and previous studies may have an effect on the difference in categorization based on knee kinematics at slow gait speed.  Second, the present study did not measure gait with daily-used AFOs; thus, it was unclear whether daily-used AFOs were the most appropriate.  Third, SG3 did not have any features of maximum knee extension in the stance phase (−1.8 ± 9.4°) with a slow gait speed.  Previous studies showed that there were 2 types of maximum knee extension (i.e., excessive knee flexion and extension) in groups with slow gait speed.  There was no difference in plantar flexor activity or ankle plantarflexion moment in the stance phase between the SGs with 2 knee types in previous studies.  The categorization in this study was based on QJS, which was attributed to ankle plantarflexion activity and moment in the stance phase during gait.  Therefore, SG3, with a slow gait speed, was not divided into 2 knee types as in previous studies.  Fourth, the present study was cross-sectional.  Future research should prospectively follow patients after stroke to clarify whether similar SGs exist before determining daily used AFOs.  Fifth, the sample size of SG1 was small.  A future study to measure and analyze QJS in a larger sample size is needed.

In a systematic review, Daryabor et al (2022) examined the effectiveness of AFO types and comparison between them on the energy expenditure metrics of walking in individuals who had suffered a stroke with (sub)acute or chronic evolution.  The following databases were searched: PubMed, Scopus, ISI Web of Knowledge, Embase and Cochrane Library based on the population intervention comparison outcome (PICO) method.  A total of 15 trials involving 195 subjects were selected for the final evaluation.  All trials, except 1, examined individuals in chronic phase.  Although the evidence from the selected studies was generally weak, the consensus was that an AFO may have a positive immediate effect on the energy expenditure metrics including energy cost, physiological cost index, mechanical work and vertical center of mass trajectory on the affected leg, in both over-ground walking and treadmill walking in adults with chronic stroke.  There were insufficient studies to examine the medium-term effectiveness of wearing an AFO combined with gait training on metabolic cost parameters during ambulation.  There were also insufficient studies for comparison among different designs of AFOs.  The authors concluded that although the studies were somewhat weak in scientific rigor and had moderate risks of bias, this review showed that an AFO could make an immediate, short time improvement in the energy cost of walking, while the AFO is worn.  Concerning the effects of long-term use of an AFO along with training, there was largely insufficient evidence to reach a valid conclusion.  There were also insufficient data for comparison among different designs of AFOs.  Moreover, these researchers stated that there is a need for further well-designed randomized trials to examine long-term effect of gait training using AFOs and comparison among the different types of orthoses.

The authors stated that the major drawbacks of the generalizability of the current review were related to the nature of the data.  Most trials examined the immediate effects of AFOs in the chronic phase without gait training, had small sample sizes, low-to-moderate scientific rigor and high risk of bias.  Current AFO research lacks high-quality RCTs with appropriate statistical power and high scientific rigor.  Statistical power analyses to determine the appropriate sample size for the experiment was calculated in only 2 studies.  There were no data to examine the effect of an AFO with variable plantar-flexion resistances on the energy expenditure metrics.  Only 2 pilot studies examined its effect on the center of mass (COM) displacement.  Moreover, the AFO-footwear combination could create different results.  However, subjects in some studies walked with an AFO only and subjects of some studies walked with an AFO associated with a shoe.  Finally, few studies examined the comparison among different types of AFOs and the comparison between the non-articulated and articulated AFOs on energy expenditure metrics in stroke hemiplegia.

These researchers stated that future investigations should therefore:

• Concentrate on RCTs with high scientific rigor and low risk of bias, especially by improving subject sampling methods, the blinding of investigators making measurements, similar time periods in all conditions, random allocation, and prevention of losses to follow-up;
• Provide a more detailed physical examination data for the post-stroke individuals in each study, and categorize subjects accordingly (e.g., if the subject has knee hyper-extension, plantar-flexor spasticity, or supra-pelvic involvement, the appropriate AFO needs to be provided accordingly;
• Use a prospective sample size calculation in order to attain a more accurate assessment of orthotic interventions;
• Clarify the relationship between the energy cost of gait and the upper body movements, walking balance, coordinated activities of muscles or positive ankle joint power using an AFO;
• Evaluate the long-term effect of gait training using AFOs in chronic and (sub) acute phases;
• Examine the effect of different types of AFOs and conduct a comparison among them on gait after stroke;
• Quantify the mechanical characteristics of the type of AFO used in the study, including torque-angle measurements in dorsiflexion and plantar-flexion to document the effect on the subject’s gait kinematics, kinetics, muscle activation and energetic cost metrics.

Ankle Orthoses for Improvement of Postural Stability in Individuals with Chronic Ankle Instability

Tang et al (2023) stated that chronic ankle instability (CAI) is a prevalent condition characterized by recurring instances of the ankle giving way and persistent symptoms, including pain and reduced function.  Foot and ankle external supports are often used in clinical practice and research for treating CAI.  In a systematic review, these investigators examined the effects of foot and ankle external supports on postural stability of individuals with CAI to guide clinical practice and inform future research.  They carried out a comprehensive search in PubMed, Web of Science, Scopus, and Google Scholar databases from January 1, 2012 to November 1, 2022.  A total of 18 studies entailing individuals with CAI were chosen in this analysis.  The quality of the included studies and risk of bias were assessed using Cochrane Collaboration's tool for RCTs, the Newcastle-Ottawa Scale for case-control studies, and the DELPHl-list for cross-over trial studies.  The external supports included in this review were ankle orthoses (elastic, semi-rigid, and active orthoses), taping (kinesio-taping and fibular reposition taping [FRT]), as well as insoles (textured and supportive insoles).  The outcome measures included static and dynamic postural stability tests, such as the single-leg stance test, star excursion balance test, Y-balance test, single-leg landing test, lateral jump test, walking test, and running test.  The results revealed that elastic orthoses, kinesio-taping, as well as textured insoles showed potential benefits in improving postural stability in individuals with CAI.  Elastic orthoses decreased ankle joint motion variability, kinesio-taping facilitated cutaneous receptors and proprioceptive feedback, while textured insoles increased tactile stimulation and foot position awareness.  However, the effects of semi-rigid orthoses, fibular re-position taping, and arch support insoles were inconsistent across studies.  The authors concluded that this systematic review provided a comprehensive overview of the effects of various foot and ankle external supports on the postural stability of individuals with CAI.  The results showed that elastic orthoses, kinesio-taping, and textured insoles showed potential benefits in improving postural stability in individuals with CAI.  Physicians, physiotherapists, podiatrists, and other healthcare professionals could consider these strategies to improve the stability of their patients with unstable ankles.  However, the effects of semi-rigid orthoses, FRT, and arch support insoles remain inconclusive.  These researchers stated that to advance the current knowledge, future studies should examine the long-term effects of external supports on postural stability in individuals with CAI.  Furthermore, it is important to analyze the effects of different characteristics and combinations of external supports to determine the most effective interventions.  Moreover, standardized outcome measures as well as testing protocols for postural stability assessment would facilitate the comparability and integration of research findings.

The authors stated that this systematic review had several drawbacks.  First, these investigators did not conduct a meta-analysis to quantitatively synthesize the results or estimate the overall effect size of the external supports.  This was due to the high heterogeneity of the included studies, which limited the validity and reliability of the meta-analysis.  However, a meta-analysis would have provided more robust and precise evidence for the effects of external supports on postural stability in individuals with CAI.  Second, these researchers did not consider the potential moderators or mediators of the effects of external supports, such as sex, age, and severity of CAI.  These factors may confound or moderate the effects of external supports in different subgroups among individuals with CAI; thus, these findings may not be generalizable or applicable to all individuals with CAI.  Third, the heterogeneity of the stability measurement methods across studies.  The authors did not examine the same aspect of stability, as some were dynamic, and others were static, which may compromise the comparability and validity of these findings.

Singh et al (2023) noted that CAI is a disorder that occurs after 1 or more acute ankle sprains and is characterized by persistent symptoms, which include episodes of ''giving way'', a sensation of instability, recurrent ankle sprains, as well as functional deficits.  Despite effective treatment strategies, a comprehensive approach is needed that can break this continuum of disability and improve the postural control.  In a systematic review with meta-analysis, these investigators examined the effectiveness of interventions targeting plantar cutaneous receptors for improving postural control in individuals with CAI.  This systematic review with meta-analysis was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.  Outcome measure used to examine the improvement in which static postural control was evaluated on single limb balance test (SLBT) and center of pressure (COP) whereas dynamic postural control was assessed on star excursion balance test (SEBT) and scores expressed as mean ± SD and random-effects model were performed, and heterogeneity between the studies was calculated using the I2 statistic.  A total of 168 CAI populations were included among the 8 selected studies in the meta-analysis; 5 studies using plantar massage and 3 studies using foot insole were assessed, with moderate-to-high quality on the Pedro scale (range of 4 to 7).  For single and 6-sessions of plantar massage showed insignificant effect on SLBT COP and for the single session of custom-molded foot orthotics showed insignificant effect on SEBT.  The authors concluded that the findings of this meta-analysis showed non-significant pooled results for plantar massage and foot orthotics on static and dynamic postural control when assessed on postural outcome measures.  These researchers stated that further prospective, randomized studies with larger sample sizes and longer follow-up are needed to ascertain the importance of sensory targeted approaches for the treatment of postural instability in CAI patients.

Ankle Foot Orthoses for Improvement of Balance in Individuals with Multiple Sclerosis

Ashkar et al (2022) noted that MS refers to a progressive autoimmune inflammatory disease in the CNS usually accompanied by balance disorder.  In a systematic review, these investigators examined the effects of orthotic devices on balance control of patients with MS.  The search procedure was according to the population, intervention, comparison, and outcome (PICO) strategy.  These researchers queried PubMed, Embase, ISI Web of Knowledge, and Scopus databases, and included all studies published since 1980.  Two researchers did the searches separately and evaluated the selected papers' quality based on the physiotherapy evidence database (PEDro) scale and Cochrane risk of bias tool.  They conducted a meta-analysis to examine the interventions' effects on the balance factors.  These researchers found 9 studies, of which 7 studies with 162 subjects were included in the meta-analysis – 4 studies examined the effect of foot orthoses, 1 examined the effect of shoe modifications, and 4 examined the effect of ankle foot orthoses.  There was no significant immediate difference between the insole and control groups in center of pressure (COP) velocity change, C7 displacement, in both open and closed eyes conditions.  Furthermore, there was no significant immediate difference between ankle foot orthosis' intervention and control groups in COP velocity and displacement changes in antero-posterior and medio-lateral directions, in both open and closed eyes conditions.  These investigators could not perform a meta-analysis for shoe modification.  The authors concluded that few studies have examined the effects of orthoses on balance control in MS patients.  Studies on ankle foot and foot orthoses showed inconsistent results.  These investigators stated that according to the findings of this meta-analysis, orthotic interventions did not appear to improve the balance of patients with MS.

References