Steppage gait is the inability to lift the foot while walking due to the weakness of muscles that cause dorsiflexion of the ankle joint. Foot drop is not a commonly seen condition. The typical presentation is one of a patient who presents with a sudden onset of weakness of the muscles that extend the foot during walking. The history usually consists of unusual activity, a surgical procedure, prolonged bed rest, accident leading to fracture, or a tight cast applied to the lower extremity. The other possibilities include a history of collagen vascular diseases leading to nerve ischemia. Peripheral neuropathies, the most common cause being diabetes, can lead to unilateral or bilateral foot drop. Upper motor neuron lesions can also present as foot drop. However, the presentation also includes hemiplegia and aphasia.
Any damage or compression of the neuraxis anywhere along this pathway can potentially lead to foot drop, and steppage gait. Frequent reasons include traumatic injuries, pelvic fractures, tibia or fibular head fractures, tight casts, prolonged positioning in lithotomy during surgical procedures, compression by a space-occupying lesion, vascular impairments as in conditions as lupus, or Waldenstrom macroglobulinemia which can lead to vasculitis causing nerve ischemia. Neuropathies affecting the nerves of the peripheral nervous system are referred to as peripheral neuropathies. These can be primarily demyelinating, primarily axonal, or mixed. Primary demyelinating neuropathies can be acquired or congenital. Examples of acquired neuropathies include acquired inflammatory demyelinating polyneuropathy (AIDP) and chronic inflammatory demyelinating polyneuropathy (CIDP). Hereditary neuropathies include Charcot-Marie Tooth (CMT), and hereditary preponderance to pressure palsies (HNPP).
Predominantly axonal neuropathies are seen with exposure to toxins, viral or bacterial infections, chemotherapeutic agents as vincristine or vinblastin.
Diabetes, alcohol intoxication and renal disease can lead to mixed peripheral polyneuropathies.
The primary causes of foot drop include cerebral vascular accident (CVA) and amyotrophic lateral sclerosis. CVA presents as hemiparesis or hemiplegia, associated with dysphagia, dysarthria, or aphasia.
Foot drop with high steppage gait is of the upper motor neuron type.
Peroneal neuropathy is more common in males (male-to-female ratio, 2.8 to 1). Approximately 90% of peroneal lesions are unilateral, with no preference to the side.
The most common presenting complaint is the inability to ambulate as before, due to the weakness of the muscles responsible for maintaining the foot in dorsiflexion during heel strike, which can lead to falls. History is usually positive for either a cerebrovascular accident (CVA), collagen vascular diseases, surgery, fracture of tibia or fibula, or prolonged stupor state and protracted bed rest as in the ICU.
Physical examination reveals the weakness of the anterior compartment muscles of the leg. Sensory loss involves the anterior aspect of the foot. Reflexes may be brisk, with upgoing plantar reflex in CVA cases or absent in lower motor neuron (LMN) disorders.
Diagnostic testing should include plain X-rays of pelvis and tibia/fibula to rule out fracture or dislocation in case of trauma. Suspected plexopathies may indicate magnetic resonance imaging (MRI).
Mild cases warrant a referral to physical therapy for pain reduction and strengthening exercises to the weak muscles coupled with a range of motion (ROM) to the ankle to prevent contractures. If EMG shows complete loss of neural continuity along with evidence of neurotmesis or axonotmesis, an ankle-foot orthosis (AFO) is indicated. The purpose of the brace is to maintain the foot in neutral during the toe-off phase of the gait cycle. Periodic skin checks are necessary since the anesthetic foot can develop pressure ulcers at the contact points with the brace. A shoe wide enough to accommodate the brace is necessary.
A home exercise program should be an integral part of therapy.
The differential diagnosis of this condition is quite broad and encompasses a wide range of neuromuscular disorders from the cerebral cortex to the peripheral nerve.
Other types of gait which require differentiation from steppage gait are:
EMG and NCV studies are beneficial to diagnose the nature, location of compression, and prognosis. If the test shows delayed latency and slow velocity, as well as conduction block at the involved segment with no evidence of denervation potentials and plenty of motor units on needle EMG, it indicates neurapraxia with a good prognosis. Conversely, if there is evidence of denervation potentials coupled with no viable motor units, the prognosis is guarded.
Complications mostly relate to the inability to clear the ground during walking, which leads to falls. The ill-fitting brace can potentially cause skin abrasions by rubbing against anesthetized skin. Parts of braces can eventually become loose due to wear and tear.
A consultation with physical medicine & rehabilitation (PM&R) specialist is necessary. A physiatrist will perform an evaluation, electrodiagnostic studies, and brace management.
Physiotherapy referrals are usually taken care of by the physiatrists.
They also can refer the patient to an orthotist for a brace.
The patients should obtain the following consultations should be obtained:
The patient is an integral part of the team. They should be included in the diagnosis and other decision-making processes, including management options. Education regarding exercises, home exercise programs, skincare, and brace maintenance will result in better outcomes.
A patient with foot drop may present with weakness of the anterior muscles in the leg, which may be due to central or peripheral causes. A careful history and physical examination are an integral part of the assessment. The nurse practitioner or a primary care specialist needs to refer to a neurologist and/or a PM&R specialist. Coordination with a physical therapist and an orthotist play a significant role in better recovery and improved outcomes. These patients need to be followed for a long time, as recovery is rarely immediate. In fact, some patients may need to wear an orthotic appliance for life. A nurse with specialized orthopedic training is also a useful member of the team, monitoring the patient, serving as a bridge with the treating clinician, as well as counseling the patient. All these members of the interprofessional health care team have a role to play in managing foot drop patients to achieve an optimal benefit to the patient. [Level 5]
|||Tehan PE,Fox M,Stewart S,Matthews S,Chuter VH, Lower limb vascular assessment techniques of podiatrists in the United Kingdom: a national survey. Journal of foot and ankle research. 2019 [PubMed PMID: 31139263]|
|||O'Brien S,Gallagher N,Spence D,Bennett D,Dennison J,Beverland DE, Foot drop following primary total hip arthroplasty. Hip international : the journal of clinical and experimental research on hip pathology and therapy. 2019 Mar 26 [PubMed PMID: 30912466]|
|||Bowley MP,Doughty CT, Entrapment Neuropathies of the Lower Extremity. The Medical clinics of North America. 2019 Mar [PubMed PMID: 30704688]|
|||Lezak B,Summers S, Anatomy, Bony Pelvis and Lower Limb, Extensor Hallucis Longus Muscle . 2019 Jan [PubMed PMID: 30969697]|
|||Lezak B,Summers S, Anatomy, Bony Pelvis and Lower Limb, Leg Anterior Compartment . 2019 Jan [PubMed PMID: 30969547]|
|||Moon DK,Johnson AMF, Lower Extremity Problem-Solving: Challenging Cases. Physical medicine and rehabilitation clinics of North America. 2018 Aug; [PubMed PMID: 30626518]|
|||Stewart JD, Foot drop: where, why and what to do? Practical neurology. 2008 Jun [PubMed PMID: 18502948]|
|||Ramdharry G, Peripheral nerve disease. Handbook of clinical neurology. 2018 [PubMed PMID: 30482330]|
|||Manckoundia P, [Gait and balance disorders]. La Revue du praticien. 2018 Dec; [PubMed PMID: 30869237]|
|||Steele KM,Munger ME,Peters KM,Shuman BR,Schwartz MH, Repeatability of electromyography recordings and muscle synergies during gait among children with cerebral palsy. Gait & posture. 2019 Jan [PubMed PMID: 30396059]|