Hydrotherapy or water therapy involves the use of water for the treatment of different diseases (like arthritis) and to strengthen muscles and joints. The only thing that differentiates it from normal swimming is its use of warm water and water walking machines is one of the best ways for water therapy.

It is beneficial for the body because water possesses many healing properties due to its thermal and mechanical effects. Less pressure is exerted on the body in water and the body feels light which makes it easy to exercise. The presence of hot and cold water affects the body differently. Coldwater regulates the blood flow and stimulates internal functions of the body whereas hot water is used to soothe the pain in muscles and joints.

Many instruments and equipment are used for hydrotherapy. Hydrotherapy tubs, showers, whirlpools, hot tubs, underwater treadmills, water walking machines, dumbbells, physiotherapy tanks are some of the important equipment. Different styles of hydrotherapy tubs are available. Some are designed so that only one person can fit comfortably while some are made for multiple people. These tubs also contain underwater Jets. 

Some of the instruments developed for exercising in water are ankle weights, kickboards, foam dumbbells, and resistance gloves. In addition to these, underwater treadmills are a great addition to water treatment. These machines help the patients to improve their gait. Muscle soreness is also reduced greatly by these treadmills. They have different features like speed, the direction of water which help in exercising and rehabilitation.

Some hydrotherapy pools contain adjustable water currents. Jets are also present which help to relax muscles.