From exercise to medications to modalities, clinicians have a lot of tools at their disposal to treat foot drop. Just as its causes are many, so are the treatments. While the same approach may not work for each patient, trial and error can help doctors and physical therapists figure out the best possible outcomes.
Foot drop is not a disease itself, but rather a symptom that develops as a result of various neurological, muscular or anatomical problems. Patients who suffer have difficulty lifting the front part of their foot due to muscle weakness or paralysis. Sometimes they drag their toes along the floor as they walk.
In a normal gait cycle, the toes pull up from the floor so a person avoids tripping on them. The toes of foot drop patients point down and strike the floor first, with their ankle flapping as they move the foot. They may develop a steppage or marching gait, raising their thigh when walking in a motion similar to climbing the stairs.1
Finding the Cause
Some of the common reasons patients present with foot drop include stroke, spinal cord injury or injury to the peroneal nerve on the outside of the fibula, below the knee. ALS (Lou Gehrig's disease), Parkinson's disease and multiple sclerosis can also lead to foot drop. Patients who have had a total knee replacement can also present with foot drop, although that is less likely. Moshe Lewis, MD, MPH, chief of the department of physical medicine and rehabilitation, California Pacific Medical Center, San Francisco, described one unique case where a surfing accident lacerated someone's peroneal nerve, causing foot drop.
The first step in treatment is determining the cause of foot drop in each patient. "If you see someone with foot drop, don't assume it's coming from the foot," cautioned Angela Levy, DPT, physical therapist, Specialty Hospital at Levindale in Baltimore.
Dr. Levy takes a personal interest in foot drop, as she suffered from a minor case herself, caused by a blow to her peroneal nerve during a rugby match. Luckily, she had minimal nerve damage but the experience has made her more sympathetic to her patients.
A nerve conduction test, for example, will see if the issue comes from the peripheral nervous system. A basic muscle test to see if someone can dorsiflex the ankle will test foot strength. If there is no active movement, i.e., the patient can't actively raise his toes, physical therapists have a bigger issue to address. Clinicians at the National Rehabilitation Hospital in Washington, DC, for example, will conduct a gait analysis, putting patients in situations that could provoke foot drop, such as climbing stairs or walking on ramps.
Treatment depends on the patient's age, physical condition and co-morbidities. "We need to make them functional and safe when they walk, but also think long-term. How can we help them regain what they lost?" asked Emily Lanham, PT, DPT, day treatment physical therapist at WellStar Kennestone Outpatient, Marietta, GA.
The goal of treating foot drop is to get patients back to a regular gait cycle. "If you throw off the gait cycle, it throws off everything else in the body," said Dr. Levy.
As Dr. Moshe explained, all foot drop patients at the California Pacific Medical Center will undergo physical therapy to "retrain and strengthen the muscles." He added, "The sooner we get them up and moving, the more motivated they feel."
It's important for patients to continue their exercises, even on the days they don't have therapy. "The more active patient makes greater gains and faster gains and is less likely to get depressed," noted Dr. Moshe. In patients with active movement, exercise strengthens the connection between the muscle and the brain.
On the other hand, at Specialty Hospital at Levindale most of the patients are fairly medically compromised. Therefore, therapists start with basic mobility and respiratory intervention and address foot drop when patients demonstrate increased independence with mobility, such as improved sitting balance, transfers and standing tolerance. Once patients are medically stable, they are transferred to the acute rehab unit where PTs work to address foot drop.
The Old and The New
Other than exercise, clinicians have other options to treat foot drop. "We're seeing a blend of the old and the new," said Dr. Moshe regarding treatment. He cited vitamin therapy, particularly B6, as helpful. Nerve medications, which are relatively new on the scene, decrease pain and improve nerve function without peripheral swelling. Topical pain medications are another new development but Dr. Moshe advised his fellow physicians to use them wisely.
In reference to modalities, ankle-foot orthotics are the "gold standard as far as physical therapy treatment," noted Dr. Levy. The AFO is an insert in the shoe that holds the foot in proper position, with the ankle and toes raised. Patients who drag their toes or have no active movement are often fitted with an orthotic. The ankle-foot orthotic reduces fall risk and immobilizes the ankle.
"There is a lot of new technology with AFOs," said Bonnie Pancoast, PT, DPT, outpatient physical therapist, Neurological Day Program, National Rehabilitation Hospital. "They're making them more adjustable to accommodate patients with different lifestyles and physical dimensions." Some patients will need to use an AFO permanently; however that means they can get around independently, which therapists consider a success.
Physical therapy and ankle-foot orthotics are two of the three main treatments for foot drop; electrical stimulation is the third. With neuromuscular electrical stimulation (NMES), the anterior tibialis muscle is directly stimulated. This helps the nerves fire, making the muscles contract. Over time, the idea is that the leg muscles will be retrained.
Clinicians start using NMES while patients are in a resting position, so they can get used to it. Patients try to move their foot back and forth while the machine is cycling. They are encouraged to focus on their leg to reintegrate the brain and nerves to train the muscles to work properly again.
Later, patients walk on a flat surface as the physical therapist controls the NMES, pulling their foot upward when the muscle is stimulated and dropping it back down during the "off" portion of the cycle. Eventually, patients progress to walking on stairs, curbs etc. without the aid of the NMES. However, one downside to neuromuscular electrical stimulation is the potential for user error, as a therapist must control stimulation during the gait cycle.
One alternative that the therapists at the National Rehabilitation Hospital use is patterned electrical neuromuscular stimulation. The inventor of this electrical stimulation unit did EMG studies for normal patterns of movement. Electrical stimulation from the unit mimics those patterns, trying to regain normalcy.
Foot drop patients are treated for 15 minutes, followed by exercise. According to Dr. Pancoast, this treatment gives patients around two hours of positive physiological effect. Some patients can regain the foot strength or movement they lost.
At WellStar Kennestone Outpatient, as well as at the National Rehabilitation Hospital, physical therapists have another, newer tool to treat foot drop. A neuroprosthesis is a three-piece device that has a cuff strapped below the knee to stimulate the peroneal nerve; an insert in the heel of the shoe that stimulates the nerves in the foot and ankle during the gait cycle; and a controller.
The three components communicate wirelessly with each other. Patients can wear the device while doing functional activities as the sensor adapts to changes in walking speed and terrain. The device facilitates muscle re-education and improves how patients walk.
One major drawback, however, is cost. The device is very expensive and is therefore only for clinic use; patients do not use it at home. "I consider it a great tool but sometimes we need other things to help the patient get better," acknowledged Dr. Lanham.
Indeed, all of the treatments for foot drop are simply tools for the patient to improve mobility. Depending on the root cause of foot drop, it may or may not be cured. Foot drop caused by trauma and/or nerve damage has the potential for partial or in some cases, complete recovery. Foot drop caused by neurological disorders will not be cured; rather it will be a life-long symptom that patients can learn to manage through exercise and modalities.
"People can be functional and independent with this symptom," said Dr. Pancoast. "There are ways to move with it." She added, "Technology is advancing every day. It's interesting to see what people will come out with in the future."
1. Mayo Clinic. Foot Drop. www.mayoclinic.com/health/foot-drop/DS01031. Accessed December 5, 2011.
Danielle Bullen is an associate editor at ADVANCE and can be reached at firstname.lastname@example.org