Posts Tagged orthotic
By Uzo Igwegbe, PT, MPT
Foot drop, a gait abnormality, is an insufficient ability to dorsiflex or clear the foot/feet during the swing phase of gait, causing an increased risk for stumbling, falls, or injury. In a normal gait cycle, initial foot contact occurs with the heel; however, an individual with foot drop may drag the foot and/or make initial contact with the forefoot or foot flat. To compensate they may excessively flex the hip and knee, or circumduct the affected limb, or increase time spent in swing phase of the affected extremity.
The cause of drop foot is due to damage to the common fibular (peroneal) nerve (inclusive of the sciatic nerve), weakness or paralysis of the tibialis anterior, extensor halluces longus and extensor digitorum longus. Foot drop is associated with cerebrovascular accident/stroke, brain injury, multiple sclerosis, cerebral palsy, spinal cord injury, spinal stenosis, disc herniation, poliomyelitis, diabetes mellitus, Charcot-Marie-Foot Disease, muscular dystrophy, Amyotrophic Lateral Sclerosis, or direct injury to the peroneal nerve.
Ankle foot orthotics (AFOs) and Functional Electric Stimulation (FES) technologies are used in the management and treatment of drop foot in physical therapy. These two approaches strive to facilitate a natural gait with increased speed, improved balance, confidence, safety, and independence with ambulation and functional mobility.
Product ResourcesThe following companies provide products to treat ankle injuries, foot drop and other aspects of stroke and neurological rehabilitation:
Allard USA Inc
GAITRite/CIR Systems Inc
Motorika Medical Ltd
Ankle foot orthotics, the most common approach used, support neutral foot position to facilitate clearance during swing and provide ankle stability during loading response.1 AFOs are either off the shelf (for short-term use) or custom made from a cast (for complex cases or long-term use). These L-shaped braces are worn in footwear and, in most cases, a larger shoe size of one half to a full shoe size may be required due to the bulk of the orthosis. To obtain an AFO, a correct foot drop diagnosis by the therapist/physician and a physician’s AFO prescription is needed to proceed with a comprehensive assessment, with recommendations of treatment options from a licensed orthotist. A cast impression of the foot and leg is done for custom AFO. Follow-up appointments are done after reception of the AFO for re-evaluation of fit and function. The AFOs prescribed for drop foot include:
1) Posterior Leaf Spring AFO:This prefabricated, semi-rigid, polypropylene AFO supports individuals with mild foot drop and knee instability. It provides dorsiflexion during swing and controls plantarflexion at heel strike. Resistance to plantarflexion can be controlled by modifying the ankle and footplate trim lines. This AFO is the initial “go-to” brace for physical therapists because they are readily available, lightweight, inexpensive, and can provide initial ankle stability early in rehabilitation; however, there are newer, lighter, more comfortable, user-friendly and functional models available. Sources for these types of AFOs include Orthotic & Prosthetic Lab Inc, Webster Groves, Mo, which makes the Dynamic ROM AFO, and Orange County, Calif-headquartered, Össur Americas, which offers a prefabricated, polypropylene AFO Leaf Spring.
2) Solid AFO: This custom-fabricated plastic AFO prevents plantarflexion and prevents/limits dorsiflexion. It supports the ankle-foot complex in the coronal and sagittal planes in individuals with complete or nearly complete loss of dorsiflexion and mild to moderate knee hyperextension. Although bulky, it provides significant ankle support. It is contraindicated in individuals with fluctuating edema due to its rigid structure. Its bulk, difficulty obtaining properly fitted footwear, and general discomfort due to heat generated from continuous use can be barriers to utilization. One source for these devices is Kiser’s Orthotic and Prosthetic Services Inc, Keene, NH, which manufactures its solid ankle AFO to help combat spasticity, help the toe to clear, and prevent the Achilles tendon from tightening.
3) Free Motion Articulating AFO: The ankle joint here is activated, so the individual must have active ankle motion. It is commonly prescribed for individuals with some dorsiflexion, but who still need frontal plane stability. It is not recommended for patients with significant quadriceps weakness. Among the products available in this category is the Exos Free Motion Ankle from DJO Global Inc, Vista, Calif; a prefabricated AFO made to be moldable, adjustable, and can be custom fit. Becker Orthopedic, Troy, Mich, also offers a plastic AFO with articulating ankle, which can be used with a variety of the company’s thermoplastic ankle joints and posterior stops.
4) Short Leg AFO with Fixed Hinge: A good option for people who have flatfoot and drop foot, this AFO holds the foot at 90 degrees to the lower leg and controls unwanted inward rotation of the foot, which is common in stroke and Charcot-Marie Tooth patients. It is relatively light and easily fits footwear. A disadvantage of this brace, and the solid AFO, is its failure to provide a natural gait. Among the sources that offer this type of orthoses is New Linox, Ill-headquartered Rinella Orthotics & Prosthetics Inc.
5) Dorsiflexion Assist AFO: This has a spring-like hinge which assists the ankle with dorsiflexion as the foot comes off the ground for those with mild to moderate drop foot, and a flat or unstable foot as it offers a more natural gait pattern. The short lower leg length of this brace and the Short Leg AFO fails to provide adequate support in people over 6 feet or 225 pounds.
6) Plantarflexion Stop AFO: This brace prevents plantarflexion and has a hinge that facilitates normal dorsiflexion. Due to its cumbersome size, it is not utilized often but can be effective in people with more severe or spastic drop foot. Orthotic & Prosthetic Lab Inc provides plantarflexion stop AFOs that are designed to prevent unwanted plantarflexion while permitting free dorsiflexion. These AFOs are also available from Yakima, Wash-headquartered Yakima Orthotics & Prosthetics, and are designed to provide medial/lateral stability and plantarflexion/dorsiflexion control.
7) Energy Return AFO: This prefabricated, lightweight AFO is made of carbon graphite material. It provides assistance in dorsiflexion and energy return at push-off to propel the individual forward with plantarflexors. It provides stability only in the sagittal plane; however, a foot orthotic can be placed on the flat foot for frontal plane stability. In stroke and spina bifida patients, carbon-fiber AFOs increased walking speed and decreased energy cost when compared to unbraced walking.2 Research suggests that Energy Return AFOs facilitate plantar flexor muscle regeneration and prevents atrophy.3,4
Therapists have a number of choices in this category, including the ToeOff carbon composite dynamic response floor reaction AFO from Allard USA Inc, Rockaway, NJ; designed to keep the foot up during swing phase as well as provide soft heel strike and stability in stance. In addition to providing good toe-off to the wearer, the company recommends this AFO for foot drop in combination with no spasticity to moderate spasticity. The Ypsilon, also from Allard, is made to provide toe-off assistance to stable ankles while also allowing natural ankle movement, while the company’s BlueROCKER provides more rigid orthopedic control and was developed for bilateral foot drop. It can be used for foot drop in combination with no spasticity to severe spasticity, as well as partial foot amputations, impaired balance, and weakness or impairment in multiple leg muscle groups. The Peromax carbon fiber AFO and Trulife Matrix Max carbon fiber AFO are two other options available to the PT market in this category.
Users with big toe plantar ulcerations who are unable to cope with the plastic AFO due to skin breakdown from continuous pushing off the foot plate can have the addition of a custom foot orthotic, which can help offload those areas. Items like a heel lift can be placed under the foot plate to control for knee hyperextension. Despite their advantages, this AFO is not ideal for individuals with large calves or very tall individuals, as their long stride repeatedly overextend and weaken the AFO, or individuals with spastic drop foot or tight Achilles tendon, as the overactivity of the muscle pushes down on the foot plate, excessively hyperextending the knee.
Functional Electrical Stimulation Management
The L300 Foot Drop System and WalkAide are approved medical devices for foot drop by the US Food and Drug Administration and are used in rehabilitation hospitals. The Bioness Legacy L300, L300 Go, and WalkAide consist of a lower leg cuff which holds electrode(s), providing low-level electrical stimulation to an intact peroneal nerve. The L300 Go and WalkAide use advance tilt sensor technology to monitor movement in all three kinematic planes, providing stimulation to lift the foot at the appropriate time. This makes foot clearance at various cadence and terrains feasible. They do not require a foot sensor like the Legacy L300, decreasing setup time and allowing users to ambulate with or without footwear. They can be used if knee instability and foot drop are present, promoting clinical application as majority of individuals present with both. Patients work alongside a clinician to obtain training for home use or utilize these technologies in the clinical setting.
The options available in the treatment and management of foot drop are numerous. The path to obtaining the right product involves a joint partnership between the patient, physical therapist, physician, and orthotist. The clinician must draw from the patient’s needs, abilities, facets of gait needing improvement, and special conditions specific to the patient to recommend the optimal product. In the choice between an AFO and FES device, the ultimate goal is to provide a product that will yield compliance, a normalized gait, and contribute to independent function. PTP
Uzo Igwegbe, PT, MPT, is outpatient physical therapist, senior, at HealthSouth Rehabilitation Hospital of Cypress, located in Houston, Texas. She earned her master’s degree in physical therapy at The Robert Gordon University in Aberdeen, Scotland, in February 2010. She joined HealthSouth Rehabilitation Hospital in January 2012, starting at the City View location in Fort Worth, Texas, working in both inpatient and outpatient settings, developing treatment plans for pulmonary, brain injury and orthopedics patients. Igwegbe joined the HealthSouth Cypress team in September 2013, where she primarily worked with outpatients with a wide range of neuromuscular and musculoskeletal conditions, as well as post-orthopedic surgery patients. For more information, contact PTPEditor@medqor.com.
- Farley J. Controlling drop foot: Beyond standard AFOs. Lower Extremity Review. 2009.
Danielsson A, Sunnerhagen K. Energy expenditure in stroke subjects looking with a carbon composite ankle foot orthosis. J Rehabil Med. 2004;36(4):165-168.
Wolf SI, Alimusaj M, Rettig O, Doderlein L. Dynamic assist by carbon fiber spring AFOs for patients with myelomeningocele. Gait Posture. 2008;28(1):175-177.
Meier RH, Ruthsatz DC, Cipriani D. Impact of AFO (ankle foot orthosis) design on calf circumference. Lower Extremity Review. 2014;6(10):29-35.
Earlier this month, Army Spc. Joey McElroy took his first steps in the Intrepid Dynamic Exoskeletal Orthosis, or IDEO (pronounced: eye-DAY-oh). The device squeaked a bit as he stepped briskly on an indoor track.
McElroy was hit by a car and thrown from his motorcycle on Dec. 5, 2012.
“I knew that when I looked down there was bones comin’ out of the leg that didn’t look correct. And my leg didn’t work,” he says.
Doctors were able to save McElroy’s mangled leg, but he had to learn how to walk again. Running was out of the question.
“You don’t realize how much you miss something ’til you don’t have it anymore,” he says. “The ability to be able to run again for my own health is a very big deal.”
McElroy is known as a “limb salvage patient” since he avoided amputation. Physical therapists say some patients like McElroy later decide they would be better off without the leg when see their amputee buddies running around easily on prostheses.
“For a while there I was like, ‘Just get rid of it.’ If I can be on a prosthetic in a week or two and be running, just lop it off,” McElroy says. But with the IDEO brace, “Now I’m glad it’s here.”
Air Force Staff Sgt. Anthony Mack practices the running technique required with the IDEO. You can’t land on your toes or heel — instead, you have to adjust your stride to hit mid-foot.
The brace, which was developed at the Center for the Intrepid at Brooke Army Medical Center in San Antonio, is molded out of lightweight black carbon fiber and custom-fit to each person. A foot plate inside a shoe attaches to a strut that runs up the back of the calf to a cuff.
The inventor, prosthetist Ryan Blanck, says it works kind of like a spring. Force applied to the foot plate bends the strut. As a person steps down, it bends the foot plate, transferring energy forward.
And if you use it correctly, it takes pain out of the equation.
The biggest challenge with the IDEO comes in relearning how to run. A patient can’t land on toes or heel — instead, they have to adjust their stride to hit mid-foot.
After trying to run for the first time, McElroy breathes heavily but is all smiles.
“It’s exhausting but it’s awesome,” he says. “I just wanna go faster.”
So far the Center for the Intrepid has fitted more than 550 service members with the IDEO.
Dr. Donald Gajewski, an orthopedic surgeon and director of the center, says the IDEO has made for less business in the operating room – and that’s a good thing.
“It’s great to have a bunch of people around here who I don’t know their names,” Gajewski says. “Because if I’m getting involved with their care, I’m taking a limb off.”
Gajewski admits the IDEO is not right for everyone. Some patients still have pain with it, so they opt for an amputation. But for most, the orthotic device has allowed them keep their leg. Some have gone on to run marathons, surf and jump out of airplanes. About 50 percent of IDEO users will return to active duty.
Blanck, the inventor, is now working in the private sector to bring the device to civilians. It costs around $10,000. At the Center for the Intrepid, there’s a waiting list of two to three months.
Technological advancements have led to the development of numerous wearable robotic devices for the physical assistance and restoration of human locomotion. While many challenges remain with respect to the mechanical design of such devices, it is at least equally challenging and important to develop strategies to control them in concert with the intentions of the user. This work reviews the state-of-the-art techniques for controlling portable active lower limb prosthetic and orthotic (P/O) devices in the context of locomotive activities of daily living (ADL), and considers how these can be interfaced with the user’s sensory-motor control system. This review underscores the practical challenges and opportunities associated with P/O control, which can be used to accelerate future developments in this field. Furthermore, this work provides a classification scheme for the comparison of the various control strategies. As a novel contribution, a general framework for the control of portable gait-assistance devices is proposed. This framework accounts for the physical and informatic interactions between the controller, the user, the environment, and the mechanical device itself. Such a treatment of P/Os — not as independent devices, but as actors within an ecosystem — is suggested to be necessary to structure the next generation of intelligent and multifunctional controllers. Each element of the proposed framework is discussed with respect to the role that it plays in the assistance of locomotion, along with how its states can be sensed as inputs to the controller. The reviewed controllers are shown to fit within different levels of a hierarchical scheme, which loosely resembles the structure and functionality of the nominal human central nervous system (CNS). Active and passive safety mechanisms are considered to be central aspects underlying all of P/O design and control, and are shown to be critical for regulatory approval of such devices for real-world use. The works discussed herein provide evidence that, while we are getting ever closer, significant challenges still exist for the development of controllers for portable powered P/O devices that can seamlessly integrate with the user’s neuromusculoskeletal system and are practical for use in locomotive ADL.
[ARTICLE] Therapeutic Effects of Functional Electrical Stimulation on Gait in Individuals Post-Stroke
Functional electrical stimulation (FES) to lower extremity (LE) muscles is used by individuals post-stroke as an alternative to mechanical orthotic devices during gait or as a training modality during rehabilitation. Technological developments which improve the feasibility, accessibility and effectiveness of FES systems as orthotic and training devices, highlight the potential of FES for rehabilitating LE function in individuals post-stroke. This study presents a systematic review of the carryover effects of LE FES to motor performance when stimulation is not applied (therapeutic effects) in subjects post-stroke. A description of advances in FES technologies, with an emphasis on systems designed to promote LE function is included, and mechanisms that may be associated with the observed therapeutic effects are discussed. Eligible studies were reviewed for methodological quality, population, intervention and outcome characteristics. Therapeutic effects of FES were consistently demonstrated at the body function and activity levels when it was used as a training modality. Compared to matched treatments that did not incorporate FES, no definite conclusions can be drawn regarding the superiority of FES. When FES was used as an alternative to an orthotic device, it had no superior therapeutic effects at the activity level, yet patients still seemed to prefer it.