Nearly 50 years ago, “Grandpa Ray,” who had diabetic peripheral neuropathy, had three options for controlling his foot drop: a high-steppage gaitpattern, double metal upright ankle-foot orthotics (AFOs) attached to what he affectionately referred to as his “Herman Munster shoes,” or what he ultimately resorted to—cowboy boots. Today, there is a great variety of options to address the foot drop symptom that occurs with many different disorders and diseases. The difficulty now is being knowledgeable about the plethora of products available to find the best options for each patient.
Identifying the extent and cause of foot drop is the first step in determining the best treatment options. Symptoms can vary in severity, from a patient having a heel strike but then abruptly plantarflexing (PF) into a foot slap pattern to dragging of the toes during swing phase. Foot drop sufferers may also present with high steppage or hip circumduction compensatory gait patterns. Upper motor neuron (UMN) injury etiologies include stroke, brain injury, spinal cord injury, or multiple sclerosis. Lower motor neuron (LMN) injury causes include trauma, surgery, drug toxicity, or metabolic disease. Muscular-level etiologies of foot drop include muscular dystrophy, Charcot-Marie-Tooth disease, and post-polio syndrome.
Musculoskeletal deficits may be addressed by physical therapy treatment, and home program instruction to improve flexibility and strength into dorsiflexing (DF). Strength and range of motion training tools common to most physical therapy clinics include cuff weights such as those provided by Bolingbrook, Ill-based Advantage Medical, TheraBand resistance bands, available through The Hygenic Corporation/Performance Health, Akron, Ohio, and the BAPS board, marketed by AliMed, Dedham, Mass.
For more significant PF contractures, serial casting and static and dynamic day and nighttime splints can provide a low load prolonged stretch. Many types of these devices are manufactured. For example, on the AliMed Inc website there are 24 products in this category. The products differ in sizing, adaptability, materials used, weight-bearing capabilities (including ability to off-load areas of the foot where there may be wounds or wound susceptibility), and ability to control other rotational moments. Dynasplint Systems, Severna Park, Md, and Össur, Reykjavik, Iceland, also manufacture these types of orthoses. It can be overwhelming to sort out the products in this category, so reliance on a trusted certified orthotist to help match patient needs with products can be invaluable.
Neuromuscular electrical stimulation (NMES) devices such as the Empi Continuum by Empi, a DJO Global company, Vista, Calif, or the Zynex Nexwave from Zynex Medical, Lone Tree, Colo, can be used in cases where a muscle can be stimulated to contract. Clinicians can use these handheld units in the clinic, as well as set them up for patient home use. These AC current devices, of course, will not work in a LMN injury unless substantial neural recovery has occurred. NMES can help retard atrophy and assist patients in relearning to contract the anterior tibialis muscle.
Retraining patients to contract the anterior tibialis can be enhanced with the use of surface EMG biofeedback (BFB) units that provide audio and visual feedback correlating with the degree of volitional activation. The NeuroEDUCATOR 4 system available through Therapeutic Alliance Inc, in Fairborn, Ohio, has four channels available to monitor unilateral, bilateral, agonist, and/or antagonist muscles for obtaining maximal volitional signal in a coordinated manner. The addition of monitoring motor activation while choosing home program exercises provides assurance to both patient and physical therapist that the chosen activities are indeed producing effective motor activation even when there is lack of visual motion. There are also combination NMES and BFB systems such as the MyoTrac from Thought Technology Ltd, Montreal West, Quebec, Canada, with which patients can initiate NMES to heighten contraction of the muscle after they reach a target volitional contraction guided by the BFB visual and audio display.
Whether or not recovery of motor function is in the picture, patients will typically benefit from some type of AFO intervention in the interim of recovery or as a permanent solution when recovery is not likely. The first goal of the brace is to hold up the toe so the patient does not trip during swing phase of the gait cycle. Secondly, using devices that have some flex via the property of the materials used or adding a hinge to the brace can help achieve rollover for a more fluid gait cycle and reduce energy expenditure. Alternatively, providing rigidity at the ankle can help to correct problems up the chain, such as a DF stop to reduce knee buckling or a PF stop to help reduce knee hyperextension. Adding in other kinetic chain corrections such as medial or lateral posts…..