Foot drop, a general term for difficulty lifting the front part of the foot, can be a temporary or permanent condition. The condition signals an underlying neurological, muscular or anatomical problem.
A patient with foot drop due to weakness or paralysis may exhibit behavior such as scuffing her toes along the ground. Or she may develop a high-stepping gait so her foot does not catch on the floor as she walks.
Beyond the obvious frustrations and limitations that accompany this condition, these patients are at greater risk for falls. According to physical therapists, early treatment and patient commitment to a prescribed home exercise program is often the best approach for patients with this gait abnormality.
The source of foot drop is most commonly a central neurological impairment such as stroke, multiple sclerosis or traumatic brain injury or a peripheral injury such as nerve damage stemming from knee replacement surgery.
"Controlling foot drop through strengthening, orthotics or a functional electrical stimulation foot drop system may address the instability of the ankle, limit the possibility of catching the toe during gait and increase safety and stability to decrease the potential of falls," said Gregory A. Thomas, PT, physical therapy supervisor, Rehabilitation Center at Eastern Idaho Regional Medical Center in Idaho Falls, ID.
Therapists must conduct a thorough PT evaluation that includes a complete patient history and an assessment of range of motion, strength, sensation, spasticity, reflexes and mobility. Treatment varies depending upon the cause and presentation of the foot drop. Treatment options range from therapeutic exercises including ROM, stretching and/or strengthening to electrical stimulation and gait training.
"The first thing I do with a patient is determine if the dysfunction is central or peripheral," explained Douglas O. Brown, PT, CSCS, manager of Raub Rehabilitation, Sailfish Point Rehabilitation and Riverside Physical Therapy, all part of Martin Health System in Stuart, FL. "Is it a brain injury such as stroke or MS?" Brown asked. "Or is it a pinched nerve in back or leg or damage from a hip surgery?"
Once the origin of the foot drop has been determined, Brown must determine if the patient is flaccid with no movement whatsoever. "If so, then the outcome /prognosis will not be as good as someone who exhibits some movement," he shared.
According to Thomas, PT exercises for this patient population include range of motion exercises for knees and ankles and strengthening leg muscles with resistance exercises. And, stretching exercises are particularly important to prevent the development of stiffness in the heel.
"There are no exercises that are off limits to these patients as long as the ankle is stable during the exercise," Thomas explained. "The exercises can be closed chained or open depending on the level of stability."
"We have to focus on restoring normal movement patterns but also on stability," Brown said. "Can the patient stand on one leg without swaying back and forth? It's important that we remember the static part because these patients function on different surfaces in real life."
Brown prepares patients for challenges met in the community and at home by having patients walk on foam mats in the clinic and then on various surfaces outside.
"If my patient's goal is to be able to walk the beach in her bare feet, then we need to work on uneven surfaces," Brown said.
The therapists need to understand a patient's case 100 percent and treat each one as an individual. These patients need to be assessed on their own merits, according to Brown. "If I have a patient with a traumatic ankle injury from being run over by a car, then I may stay away from certain load bearing exercises," he shared.
Enter the AFO
If a patient does not have functional use of his muscles, then an ankle foot orthosis (AFO) can be used to keep the ankle at 90 degrees and prevent the foot from dropping toward the ground, thereby creating a more even and normal gait.
The type of AFO used depends on each patient's specific needs. Some of the types most commonly used include solid ankle, articulated ankle and posterior leaf spring and are most typically made of polypropylene. Articulated ankles allow for some ankle motion, dorsiflexion assist and partial push-off during gait and solid ankle AFOs are rigid and more appropriate if the ankle and/or knee are unstable. Patients typically need to wear a larger shoe size to accommodate these types of AFOs.
"As a physical therapist, I need to realistically fulfill the goal of a patient, which in the case of foot drop, is most typically to stop using an AFO," Brown explained. "But there are other issues to consider aside from the annoyance of the device. I may need to worry about comorbidities such as diabetes and how the AFO may be causing skin breakdown."
Brown aims to improve his patients' optimum function and quality of life while decreasing the fall risk. "Once a patient tells me his goals, I need to determine if they are realistic," he told ADVANCE.
The goal of physical therapy with these patients is to use the least restrictive device, according to Thomas. "If there is active movement at the ankle and we can strengthen it back to normal, then a temporary brace can be used for support and to increase safety," he stated. "If the foot drop is more long standing, a custom fitted AFO may be needed."
In the last 10 years or so, AFOs have improved in quality and function, according to Brown. In fact, he says, some AFOs are made of carbon fiber and elicit a dynamic action instead of keeping the foot rigid while going through the swing phase of gait.
Another option is a foot drop system that applies electrical stimulation in a precise sequence, which then activates the muscles and nerves to lift the foot and bend or extend the knee. This type of device assists with a more natural gait, reeducates muscles, reduces muscle loss, maintains or improves range of motion and increases local blood circulation.
The foot drop device allows a flexible ankle during gait to obtain a more normal walking pattern. A good alternative to bracing, the device's gait sensor adapts to changes in walking speed and terrain, allowing the patient to walk easily on stairs, grass and carpet.
Brown recently treated a 37-year-old woman with early stages of MS. He put the FES foot drop system on her and it helped her walk normally for the first time in years, bringing tears to her eyes.
"FES can help patients develop great gait patterns and fire muscles," Brown observed. "FES shows the potential for improvement and the patient can rent the device themselves to wear all day instead of an AFO. The technology is helpful but the device isn't for everyone. There is a better response with central foot drop as opposed to peripheral lesions."
The device works well when the peripheral nerve is intact. Patients with a peripheral nerve injury-from diabetes or trauma-who have no palpable muscle contractions may not see improvements. "If the damage is peripheral nerve, then a FES foot drop system will not work in correcting foot drop and a passive AFO system will have to be used," Thomas shared.
If the patient's spinal cord has been interrupted in any way, then retraining the muscles would be a very difficult-and maybe even impossible-endeavor.
An AFO remains the appropriate solution for patients with lower-extremity edema, unstable ankle stance or cognitive impairments that interfere with operation of a foot drop system.
Complying at Home
For this condition, patients typically go to therapy for about 45 minutes, two times a week, according to Thomas. "If a patient is going to make gains, however, it's imperative that there is good compliance with a home exercise program," he shared. "The patients who have the greatest success are the ones with a solid work ethic outside the clinic."
Brown's approach to ensure compliance with a home program begins with the patient's first evaluation. "I tell them how important the home program is and that participation is crucial," he shared. "I put them on the spot and I go through the exercises the first day and then send them home with illustrations. I say I will quiz them during the beginning of the next session and will ask them to demonstrate the exercises I assigned."
With this approach, Brown knows whether or not they've followed through based on their familiarity with the exercises. "I give additional exercises and instruction during each session," he said. "And that's how I make sure that they are compliant. It usually works because patients come prepared because they don't want to fail."
When it comes to foot drop-and really any PT-related injury or diagnosis-Brown stresses the importance of seeking care with a physical therapist as soon as possible. "I don't want to see someone with foot drop after 6 months," he stated. "Once a patient is medically stable and safe to treat, they need to be sent to PT."
Brown recalls seeing a patient with foot drop after having a stroke one and a half years earlier. "There was a lot less I could do for her compared with what I could have done right after her stroke," he said. "It's crucial to treat these patients as soon as possible with exercise, stretching and weight bearing."
Rebecca Mayer Knutsen is senior regional editor of ADVANCE and can be reached at firstname.lastname@example.org.