Symptom Management

Foot Drop and Functional Electrical Stimulation

By Maureen Shanahan, R.N.
Like many people with MS, I have a condition known as foot drop. This condition occurs when the peroneal muscle in the front of the calf is weakened – or is only weakly stimulated by the central nervous system – preventing the proper lifting of the forefoot and toes during walking. Tightness in the muscles at the back of the calf also contributes to the condition. Foot drop, which allows the foot to dangle from the ankle, makes walking difficult and tiring. In order to avoid tripping and falling, those of us with foot drop adopt a number of abnormal gait strategies, such as swinging the affected leg outward, hitching up the hip, and leaning to one side.
Drawbacks of an AFO
Currently, foot drop is treated with a brace called an ankle foot orthosis. An AFO provides support by holding the foot at a right angle to the lower leg. As a six-year AFO user, I know the drawbacks. With an AFO, I must wear two different-sized shoes. This limits my wardrobe selection – partly because of the large shoes, but also because an AFO is difficult to put on and take off when wearing the tapered pants common in a woman's wardrobe. While the AFO does enhance my gait, walking is still difficult and tiring. The AFO can also be uncomfortable when worn for prolonged periods. Thankfully, new options for foot drop are available. In fact, the market for electrical stimulation systems is on the verge of becoming quite competitive.
The WalkAide
In March of 2006, I had the opportunity to try a new device for foot drop called WalkAide. It consists of a cuff worn just under the knee, fastened with Velcro. Inside the cuff are two gel-covered electrodes that adhere to the skin, delivering a gentle stimulus directly to the peroneal muscle, virtually bypassing the dysfunctional central nervous system. The stimulus is provided by a double-A battery placed inside a pulse generator, about the size of an iPod, attached to the outside of the cuff. No wires are needed because the device works by "tilt technology." In other words, when the calf is at a predetermined angle to the ground, a stimulus is initiated to the peroneal muscle. The device is programmed specifically for the user.
When I tried WalkAide, there was an immediate and obvious improvement in my walking. I couldn't understand exactly what was happening, but it felt so much easier. Then I saw a video of myself walking, first with the device turned off, and then with the device turned on. With the WalkAide, my movements were much smoother. I no longer twisted my torso, leaned from side to side, or held my arms at odd angles to avoid falling. No wonder it felt easier!
Walking with this device, I do not tire as quickly as with the AFO. In fact, I'm now able to walk up and down a hallway several times without feeling exhausted, or tripping and falling. It's been a nice change.
I've also been able to do some fun things, like walk barefoot along the shoreline at the beach. I used to attempt this without my AFO because using it would require wearing shoes, which would diminish the sensory experience of walking on the beach. But without the AFO, I sometimes fell and would drag my foot through the sand until I wore the skin off my toes. Hardly a pleasant experience! Using WalkAide on the beach minimized my fatigue, and kept me from tripping or injuring my toes.
As I become more comfortable, I'm starting to do errands using the WalkAide and my rollator or forearm crutch, instead of automatically opting for my scooter.
The NESS L300
A woman with MS told me about another device for foot drop, called the NESS L300. She'd observed someone using it at her physical therapist's office and was quite excited by what she'd seen. Personally, I have not yet tried this device. So, I contacted Jan Dobbs, Manager of Clinical Development at Bioness, Inc. She explained that the NESS L300 is also a functional electric stimulator. It operates with a wireless heel sensor and sophisticated software to detect gait events and a wireless, hand-held control unit. The stimulation unit and the electrodes are integrated into an orthosis that utilizes anatomical landmarks on the user's leg for accurate and reproducible electrode placement.
Besides improving gait, these devices may increase mobility, strength, endurance, and range of motion. They may prevent, retard, or reverse muscle atrophy. Less injury, better circulation, increased bone density, and muscle re-education may also be possible. A prescription from your primary care doctor or your neurologist is required for these devices. After acquiring the device, a physical therapist can help with gait retraining.
These devices and others (including implanted stimulation systems) may not solve all of our problems and may not be perfect for everyone, but this is just the beginning of how technology might assist those of us with MS. I fantasize that someday I'll be able to pull on a pair of tights with electrodes embedded in the fabric that could literally walk me through my day. Wouldn't that be great? For now, though, these devices are a good start.
Editor's Note: These devices are not yet widely used in clinical practice and may not be covered by insurance.
To learn more:
Innovative Neurotronics, Inc. Call 888-884-6462 or visit
Bioness, Inc. Call 800-211-9136 or 661-362-4850, or visit
NDI Medical (ODFS Dropped Foot Stimulator) Call 216-378-9106 or visit
Neurodan A/S (ActiGait®) (Denmark). Visit  www.neurodan
FineTech Medical Limited (STIMuSTEP) (United Kingdom). Visit
A Registered Nurse, Maureen Shanahan is experienced in rehabilitative medicine, critical care, and cardiology research. Diagnosed with MS in 1996, she continued doing cardiology research until 1998. Mother of three grown daughters, Maureen resides in Maryland with her husband. A patient advocate for her friends and family, she uses voice-activated software to continue writing and sharing her knowledge and experience with others.
(Last reviewed 7/2009)