Nonimmersive Virtual Reality-Based Exercises Improve Muscle Excitability and Balance in Patients with Knee Osteoarthritis: A Sham-Controlled Study

<b><i>Objective:</i></b> Pain, decreased muscle strength, regression in activities of daily living (ADL), narrowing of joint range of motion (ROM), impairment of proprioceptive sense, and deterioration in static-dynamic balance are frequently observed in knee osteoarthritis (KOA). The aim of this study is to examine the effect of nonimmersive virtual reality (NIVR) application on muscle excitability and motor neuron pool activation level around the knee, balance, proprioception, physical function level, independence levels in ADL, muscle endurance, and patient satisfaction in patients with KOA. <b><i>Materials and Methods:</i></b> Forty patients with KOA were randomized to an experimental group (EG; <i>n</i> = 20) and a sham-controlled group (SG; <i>n</i> = 20). The EG received 45 minutes of traditional physiotherapy and 30 minutes of NIVR-based exercises for 3 weeks, 5 days a week, while the SG received traditional physiotherapy and a sham virtual reality (VR) application for 30 minutes for the same period. Primary outcomes were muscle excitability (maximal voluntary contraction [MVC]), motor neuron pool activation level, and balance. Secondary outcomes included proprioception, endurance, independence in ADL, pain level, physical functional condition (Western Ontario and McMaster Universities Arthritis Index [WOMAC]), and treatment satisfaction. <b><i>Results:</i></b> Findings showed a significant difference in endurance, pain level, and independence in ADL scores in favor of the EG (all values, <i>P</i> < 0.05). Moreover, WOMAC, static and dynamic balance (differences timed up and go [TUG]: EG: -4.75, SG: -2.10, <i>P</i> = 0.02, <i>d</i> = 0.907), MVC, and proprioception scores also showed the highest differences (most values, <i>P</i> < 0.001). <b><i>Conclusion:</i></b> Nonimmersive VR applications are a feasible approach for KOA and are effective approaches for increasing muscle excitability, static and dynamic balance, muscle endurance, proprioception, independence in ADL, treatment satisfaction, and reducing pain intensity in KOA.