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Treating Dropfoot with Ankle-Foot Orthoses

A tutorial on braces for patients with dropfoot
Drop foot (also known as dropfoot, footdrop and foot drop) is a term that describes a disorder where a patient has a limited ability or inability to raise the foot at the ankle joint. This makes walking difficult as the toes tend to drag on the ground which leads to tripping and instability. Patients adapt to this by using their hip muscles to exaggerate lifting the foot above the ground (known as a “steppage gait”) or by swinging their leg outward so that the foot can clear the ground (known as “circumduction”). More information on the cause of foot drop is available at the end of this page.

TREATMENT
Drop foot is often treated with the use of braces. The goal of bracing is to provide patients with a more normal and comfortable gait. At the Foot and Ankle Center of Washington we treat dropfoot with several different types of braces (also known as ankle-foot orthotics or AFOs). Our choice of which brace to make depends on each patient’s individual condition. When treating drop foot, AFOs can act in several different ways to help our patients.

To understand how AFOs work, you must first understand two standard motions that occur at the ankle joint – “dorsiflexion” and “plantarflexion”. Plantarflexion is the motion the ankle joint makes when the toes point downward. Dorsiflexion is the motion the ankle joint makes when the foot points upward. This motion needs to occur when the foot comes off the ground so that the patient does not drag their toes. Patients with dropfoot usually have a partial or complete weakness of the muscles that dorsiflex the foot at the ankle joint.

We use several different types of AFOs to treat drop foot in our patients. Some of them are custom and require that we make a mold of your foot, ankle and leg. Others are prefabricated. Our goal is to provide patients with a comfortable AFO that will give them the most normal gait possible.

REVIEW OF DROPFOOT AFOS
There are five basic types of AFOs that we can choose for our patients with drop foot:

  • Short leg fixed AFOs
  • Dorsiflexion assist short leg AFOs
  • Solid ankle AFO (with or without posterior stop). Also available with dorsiflexion assist.
  • Full leg posterior leaf spring AFO
  • Energy return AFOs

Short Leg AFO with Fixed Hinge (doesn’t flex at ankle joint)
This type of AFO is relatively light and easy to fit into shoes. It offers excellent control of the foot and is a good choice for patients who have dropfoot and also have a very flat foot. This AFO keeps the foot at 90 degrees to the leg. It can also help control unwanted inward rotation of the foot, which can commonly accompany dropfoot in stroke patients and Charcot-Marie Tooth patients.

The disadvantage of this fixed hinge version of this brace, as prescribed for dropfoot, is the fact that it does not allow plantar flexion or dorsiflexion, so it doesn’t provide quite as natural of a gait as do some of the other braces. Also because it is rather short, it doesn’t work as well on taller people. If you are over 6’ tall, we will prescribe a different brace.

Dorsiflexion Assist AFO:
This AFO is very similar to the above AFO, but with a spring-like hinge that acts to raise the foot (dorsiflex the ankle) when the foot comes off of the ground. It offers the advantage of a more normal gait pattern. This is one of the best AFOs for patients with mild to moderate dropfoot and a flat or unstable foot. One of the better dorsiflexion assist AFOs is known as a “Richie Brace Dynamic Assist”. It allows for a very normal gait in patients with mild to moderate drop foot. It’s limitations are that it won’t work well for patients who weigh over 225 lbs or are over 6’ tall. This brace is shown below. If you are outside of the Seattle area and would like to find a practitioner who uses this brace, go to www.richiebrace.com.

Plantarflexion Stop AFO:
A “plantarflexion stop” AFO acts to stop plantarflexion by not letting the foot point downward. This type of AFO has a hinge that allows for normal dorsiflexion. Due to it’s somewhat bulky size, we don’t make this brace very often. It can be effective, however, for patients with more severe dropfoot.

Solid AFO:
This type of AFO stops plantarflexion and also stops or limits dorsiflexion. These are used for dropfoot patients with a nearly complete loss of dorsiflexion strength and who also have an unstable knee. It is a bit bulky, but gives a tremendous amount of control.

Posterior Leaf Spring AFO:
This is a very traditional AFO and has been around for many years. We are not using many of these AFOs anymore as newer AFO models are often a lighter, more comfortable and easier to use. They are, however, often useful for some patients who have instability of the knee along with their dropfoot.

Energy Return AFO:
This type of AFO uses a natural flex built into the material of the AFO to provide assist in dorsiflexion. These devices are often made of carbon graphite materials. We have used many of these prefabricated AFOs lately as they provide good control with very little weight. Depending on the degree of dropfoot, we choose one of three different models:

If you have dropfoot, make an appointment today in our Seattle office so that we can work with you to find the best AFO for your condition.

MORE INFORMATION ON FOOT DROP:
The following information on Foot Drop is made available by the National Institutes of Health:

What is Foot Drop?
Foot drop describes the inability to raise the front part of the foot due to weakness or paralysis of the muscles that lift the foot. As a result, individuals with foot drop scuff their toes along the ground or bend their knees to lift their foot higher than usual to avoid the scuffing, which causes what is called a “steppage” gait. Foot drop can be unilateral (affecting one foot) or bilateral (affecting both feet). Foot drop is a symptom of an underlying problem and is either temporary or permanent, depending on the cause. Causes include: neurodegenerative disorders of the brain that cause muscular problems, such as multiple sclerosis, stroke, and cerebral palsy; motor neuron disorders such as polio, some forms of spinal muscular atrophy and amyotrophic lateral sclerosis (commonly known as Lou Gehrig’s disease); injury to the nerve roots, such as in spinal stenosis; peripheral nerve disorders such as Charcot-Marie-Tooth disease or acquired peripheral neuropathy; local compression or damage to the peroneal nerve as it passes across the fibular bone below the knee; and muscle disorders, such as muscular dystrophy or myositis.

Is there any treatment?
Treatment depends on the specific cause of foot drop. The most common treatment is to support the foot with light-weight leg braces and shoe inserts, called ankle-foot orthotics. Exercise therapy to strengthen the muscles and maintain joint motion also helps to improve gait. Devices that electrically stimulate the peroneal nerve during footfall are appropriate for a small number of individuals with foot drop. In cases with permanent loss of movement, surgery that fuses the foot and ankle joint or that transfers tendons from stronger leg muscles is occasionally performed.

What is the prognosis?
The prognosis for foot drop depends on the cause. Foot drop caused by trauma or nerve damage usually shows partial or even complete recovery. For progressive neurological disorders, foot drop will be a symptom that is likely to continue as a lifelong disability, but it will not shorten life expectancy.

What research is being done?
The National Institute of Neurological Disorders and Stroke (NINDS) conducts research related to the neurological conditions that cause foot drop in its laboratories at the National Institutes of Health (NIH), and also supports additional research through grants to major medical institutions across the country. Much of this research focuses on finding better ways to prevent, treat, and ultimately cure the kinds of neurological disorders that cause foot drop.


All pages on this website © 2008
Douglas Hale, DPM & Lawrence Huppin, DPM
Foot and Ankle Center of Washington, Seattle
The material provided on this web site is for informative purposes only.
If you need specific medical advice, please contact the office for an appointment.