Physiotherapy involves various electrotherapy, exercise, and massage techniques. Electrotherapy modalities described include shortwave diathermy, microwave diathermy, ultrasound, interferential current therapy, TENS, Faradic and galvanic muscle stimulation. Exercise therapies discussed are active/passive exercises, traction, hydrotherapy, relaxation techniques, and various stretches. Massage techniques summarized are Swedish massage, hot stone massage, aromatherapy massage, deep tissue massage, shiatsu massage, Thai massage, and prenatal massage.