Foot Drop Overview:
Foot drop, sometimes called drop foot, is a general term for difficulty lifting the front part of the foot. If you have foot drop, you may drag or bump the front of your foot on the ground when you walk. Foot drop in itself is not a disease but rather a sign of an underlying neurological, muscular or anatomical problem.
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.
In a normal walking 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 walking gait, raising their thigh when walking in a motion similar to climbing the stairs to avoid striking the front of their foot against the ground. Another coping mechanism is raising the leg and slightly bending at the knee to prevent the foot from dragging along the ground. Other gaits such as a wide outward leg swing (to avoid lifting the thigh excessively or to turn corners in the opposite direction of the affected limb) may also indicate foot drop.
Foot drop typically affects only one foot. Depending on the underlying cause, however, it’s possible for both feet to be affected.
Foot drop is a complicated condition in many cases including that of multiple sclerosis (MS).
Falling down due to foot drop is a serious hazard. If you suspect that you are experiencing foot drop as a new presenting symptom and live with multiple sclerosis it is important for you to see your neurologist as soon as possible. As a new presenting symptom you may be undergoing a new exacerbation (flare up) or problem relating to an existing lesion. Do not wait as drop foot can be a serious risk and is best addressed as soon as it presents itself.
Foot Drop Symptoms:
The most common symptom of drop foot, a high steppage gait is often characterized by raising the thigh up in an exaggerated fashion while walking, as if climbing the stairs.
High steppage gait is associated with one of the following:
- Dragging of the foot and toes
- Scraping of the toes across the ground
- Uncontrolled slapping of the toes against the ground.
The affected muscles are usually used to keep the foot off the ground during the swing-through portion of walking. When these are weak, they cannot keep the foot up and the foot will scrape across the ground if the foot is not picked up high.
Some other foot drop symptoms may include:
- An exaggerated, swinging hip motion. With foot drop, the hip may swing out in an effort to counteract the toes from catching the ground.
- Limp foot. Specifically, a foot that flops away from the body is another common drop foot symptom.
- Tingling, numbness & slight pain in the foot. Ranging from a slight tingling sensation to a complete lack of feeling in the foot, these foot drop symptoms may make everyday activities like walking and driving a car very difficult. Such foot pain may be linked to the lower back, specifically to a series of symptoms known as sciatica.
- Difficulty with certain activities requiring the use of the front of the foot. As just one example, foot drop may make an activity like climbing the stairs especially difficult.
- Muscle atrophy in the leg. Muscle atrophy refers to a muscle decreasing in mass and weakening. As the anterior tibialis, extensor hallucis longus and the extensor digitorum longus muscles are most affected by foot drop, atrophy may occur and make it much harder to exert force with the leg and the foot.
Foot Drop Causes:
Specific causes of foot drop that should be considered may include:
- A lower back condition
- A stroke or tumor
- Parkinson’s disease
- Motor Neuron disease
- Multiple sclerosis
- Adverse reactions to drugs or alcohol
- An injury to the foot or lower leg
Foot Drop Diagnosis:
Foot drop is often diagnosed during a physical examination. Your physician or neurologist will look at the way you walk and examine your leg muscles. In some cases, imaging tests, such as an X-ray, ultrasound scan or computerised tomography (CT) scan, may be required. Nerve conduction tests may be recommended to help locate where the affected nerve is damaged. Electromyography, where electrodes are inserted into the muscle fibres to record the muscle electrical activity, may also be carried out at the same time.
A typical foot drop diagnostic process includes:
- A patient history, involving an understanding of the specific foot drop symptoms, past illnesses, and use of any medications
- A physical exam, including an examination of the visual appearance and altered behavior of the affected foot and leg
Possible additional diagnostic tests, such as:
- Imaging studies to examine the surrounding areas of damaged nerves (e.g. with an MRI scan)
- Electrodiagnostic studies (EMG/NCS) to distinguish between the different types of nerve damage
- A blood analysis for a possible metabolic cause like diabetes, alcoholism, or toxins
- Fasting blood sugar, hemoglobin, and nitrogen and creatinine tests.
The physician will also explore possible other underlying causes such as injuries, neurological disorders such as MS and may ask questions related to family history.
Foot Drop Treatment:
There are numerous ways available to help manage drop foot and many devices now in research to help manage this condition.
Recovery depends on the cause of foot drop and how long you’ve had it. In some cases it can be permanent.
Making small changes in your home, such as removing clutter and using non-slip rugs and mats, can help prevent falls. There are also measures you can take to help stabilise your foot and improve your walking ability.
Treatments for drop foot include:
- Physiotherapy – to strengthen your foot, ankle and lower leg muscles
- Wearing an ankle-foot orthosis – to hold your foot in a normal position
- Electrical nerve stimulation – in certain cases it can help lift the foot
- Surgery – an operation to fuse the ankle or foot bones may be possible in severe or long-term cases
In situations where foot drop has caused a significant gait disturbance, physical therapy may be required. Specialized physical therapy for foot drop may include gait training that essentially teaches the patient how to walk all over again.
In less dramatic situations, specific exercises may simply be advised to help the affected muscles.
Physical therapy may be called for in combination with other forms of therapies such as those shown below.
An ankle-foot orthosis (AFO) is worn on the lower part of the leg to help control the ankle and foot. It holds your foot and ankle in a straightened position to improve your walking.
If your GP thinks an AFO will help, they’ll refer you for an assessment with an orthotist (a specialist who measures and prescribes orthoses).
Wearing a close-fitting sock between your skin and the AFO will ensure comfort and help prevent rubbing. Your footwear should be fitted around the orthosis.
Lace-up shoes or those with Velcro fastenings are recommended for use with AFOs because they’re easy to adjust. Shoes with a removable inlay are also useful because they provide extra room. High-heeled shoes should be avoided.
It’s important to break your orthosis in slowly. Once broken in, wear it as much as possible while walking because it will help you walk more efficiently and keep you stable.
There exists a very wide variety of orthosis so finding one that is comfortable and functional provides many options.
Electrical nerve stimulation:
In some cases, an electrical stimulation device, similar to a TENS machine, can be used to improve walking ability. It can help you walk faster, with less effort and more confidence.
Two self-adhesive electrode patches are placed on the skin. One is placed close to the nerve supplying the muscle and the other over the centre of the muscle. Leads connect the electrodes to a battery-operated stimulator, which is the size of a pack of cards and is worn on a belt or kept in a pocket.
The stimulator produces electrical impulses that stimulate the nerves to contract (shorten) the affected muscles. The stimulator is triggered by a sensor in the shoe and is activated every time your heel leaves the ground as you walk.
If your GP or consultant thinks you’ll benefit from using an electrical stimulation device, you’ll be referred to an orthopaedic foot and ankle surgeon for an assessment. You may then be referred to a specialist unit to try the device and assess its suitabilty.
For long-term use, it may be possible to have an operation to implant the electrodes under your skin. The procedure involves positioning the electrodes over the affected nerve while you’re under general anaesthetic.
The National Institute for Health and Care Excellence (NICE) advises that electrical stimulation can be used to treat people with foot drop caused by damage to the brain or spinal cord, provided:
- The person understands what’s involved and agrees to the treatment
- The results of the procedure are closely monitored
Functional electrical stimulation (FES):
Functional electrical stimulation (FES) is a treatment that uses the application of small electrical charges to improve mobility. It is particularly used as a treatment for foot drop.
Foot drop is caused by disruption in the nerve pathway to and from the brain, rather than in nerves within the leg muscles. FES applies small electrical impulses directly to the nerves in affected muscles and forces functional movement.In January 2009, NICE (National Institute for Health and Clinical Excellence) issued guidance that FES can be offered routinely as a treatment option for people with foot drop caused by damage to the brain or spinal cord if the doctor feels it is appropriate.To be suitable for the treatment, the individual needs to be able to walk, even if only a few metres with a stick or crutch. An assessment by a physiotherapist trained in the use of FES is required to ensure that the treatment will be suitable for the individual. The physiotherapist will also make sure that the pads are placed properly and that the equipment is being used most effectively.
Surgery may be an option in severe or long-term cases of foot drop that have caused permanent movement loss from muscle paralysis.
The procedure usually involves transferring a tendon from the stronger leg muscles to the muscle that should be pulling your ankle upwards.
Another type of surgery involves fusing the foot or ankle bones to help stabilise the ankle.
Speak to your GP or orthopaedic foot and ankle specialist if you’re thinking about having surgery for foot drop. They’ll be able to give you more information about the available procedures and any associated pros and cons.
The Future and Emerging Therapies:
“We’re seeing a blend of the old and the new,” said Dr. Moshe chief of the department of physical medicine and rehabilitation, California Pacific Medical Center, San Francisco 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, DPT, physical therapist, Specialty Hospital at Levindale in Baltimore. 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.”
article source: #MSUnites