The effects of adding neuromuscular electrical stimulation to standard inpatient rehabilitation on quadriceps strength and physical function in individuals with total knee replacement

INTERVENTION: Standard total knee replacement (TKR) rehabilitation with neuromuscular electrical stimulation (NMES) would be delivered separately by experienced Physiotherapists. Standard TKR rehabilitation would be delivered daily from the first day post surgery till the day of discharge. One day post surgery, NMES would be delivered daily for 4 consecutive days. Standard TKR rehabilitation comprises ambulatory, knee mobility, and knee strengthening exercises. For NMES, a portable unit will be used to deliver the electrical stimulation, and 2 pairs of self‐adhesive surface electrodes will be placed over the vastus lateralis and vastus medialis muscles of the affected (operated) limb. The NMES unit will be set to deliver a 40‐Hz biphasic current (450 microseconds pulse duration) for 5 seconds followed by a 20‐second resting period (i.e., 20% duty cycle). During each 15‐minute NMES session, a total of 30 repetitions will be performed, and the stimulation intensity will be adjusted to the maximal intensity tolerated by the patients. CONDITION: Impairments in quadriceps muscle performance following total knee replacement PRIMARY OUTCOME: Stopwatch‐timed fast paced gait speed over a 10‐metre course The primary outcome will be isometric knee extensor torque output measured by an isokinetic dynamometer SECONDARY OUTCOME: Direct health care costs, as measured by a recall questionnaire of all use of health professionals, medical tests, medications, professional home care and hospitalization Health Related Quality of Life: EuroQoL 5D Knee effusion as measured using a bioimpedance spectrometer and a measuring tape Knee extensor maximal rate of torque development (MRTD) and torque steadiness as measured using an isokinetic dynamometer Knee pain intensity measured by the numeric pain rating scale Knee passive range‐of‐motion as measured using goniometry Medical Outcomes Survey Short Form‐36 (SF‐36) physical function and bodily pain scores Physical activity level as measured by the Lower Extremity Activity Scale (LEAS) questionnaire Quadriceps lag (measured using goniometry) and the visual assessment of the patient's ability to perform an unassisted straight‐leg‐raise Standing balance and weight bearing symmetry as measured using a Wii forceplate Stopwatch‐timed habitual gait speed over a 10‐metre course Walking aids used (assistive devices are classified as wheelchair, rollator or walking frame, quadstick, or walking stick) and length of inpatient stay (measured in days using the time from the day of surgery to discharge from the hospital) Walking self‐efficacy as measured using a 5‐item questionnaire INCLUSION CRITERIA: Patients undergoing unilateral total knee replacement due to symptomatic knee osteoarthritis