Physiotherapy has evolved from ancient practices by Hippocrates and Galenus to treat injuries. It was established in the late 19th century in Britain and developed further during World War II to treat large numbers of injured soldiers. Physiotherapy uses various physical techniques without drugs, including exercise, massage, heat and electricity, to treat diseases and disabilities. It aims to relieve pain, improve mobility and function. Key techniques include electrotherapy like ultrasound and TENS, various exercises and equipment for gait training and rehabilitation.