Muscle Stimulator Market Size, Share, and COVID-19 Impact Analysis, By Product Type (Functional Electrical Stimulators [FES], Neuromuscular Electrical Stimulators [NMES], Transcutaneous Electrical Nerve Stimulation Devices (TENS), and Others), By Type (Implantable and External), By Application (Musculoskeletal Disorders, Pain Management, Neurological Disorders, and Others), By End User (Hospitals, Physiotherapy & Rehabilitation Clinics, Homecare Settings, and Others), and Regional Forecast, 2026-2034