Intramuscular Electrical Stimulation for Muscle Activation of the Tibialis Anterior After Surgical Repair: A Case Report

BACKGROUND: Loss of voluntary activation of musculature can result in muscle weakness. External neuromuscular stimulation can be utilized to improve voluntary activation but is often poorly tolerated because of pain associated with required stimulus level. Intramuscular electrical stimulation requires much lower voltage and may be better tolerated, and therefore more effective at restoring voluntary muscle activation. CASE DESCRIPTION: A 71-year-old man sustained a rupture of the distal attachment of the tibialis anterior tendon. Thirty-two weeks after surgical repair, there was no palpable or visible tension development in the muscle belly or tendon. Dorsiflexion was dependent on toe extensors. Electrical stimulation applied via a dry needling placement in the muscle belly was utilized to induce an isometric contraction. OUTCOMES: Five sessions of intramuscular electrical stimulation were delivered. By day 4 (second visit), the patient was able to dorsiflex without prominent use of the extensor hallucis longus. By day 6 (third visit), active-range-of-motion dorsiflexion with toes flexed increased 20 degrees (-10 degrees to 10 degrees). Eighteen days after the initial treatment, the patient walked without his previous high-step gait pattern, and the tibialis anterior muscle test improved to withstanding moderate resistance (manual muscle test score, 4/5). DISCUSSION: The rapid change in muscle function observed suggests that intramuscular electrical stimulation may facilitate voluntary muscle activation.