Skeletal Muscle Atrophy and Dysfunction Following Total Knee Arthroplasty

NMES will be conducted on the quadriceps of the operative leg using a portable stimulation device, starting within 48-72 hrs of surgery. The operative leg will be immobilized at a neutral angle (\~30º), with electrodes affixed to the anterior surface of the thigh. Symmetrical, biphasic pulses (400 µs duration at 50 Hz) will be used, with a duty cycle of 25% (10 s on, 30 s off), with patient-selected stimulation intensity to cause visible contractions below pain threshold. NMES sessions will occur 5 d/week, twice daily for 45 min (5 min warm-up) for 5 wks.