In many cases, an injury is caused by a series of factors working together. For example, persistent back pain can be triggered by a combination of poor posture, being overweight, repetitive work activities, and poor technique when playing sports. Exercise is the most widely used and well-known type of physiotherapy. Depending on the patient's condition, the exercises can be performed by the patient alone or with the help of the therapist, or with the therapist moving the patient's limbs. Exercise equipment for physical therapy may include an exercise table or mat, stationary bike, walking aids, wheelchair, stair climbers, parallel bars, pulleys and weights. Heat treatment is used to stimulate the patient's circulation, relax muscles and relieve pain. Cold treatment is applied with ice packs or a cold water soak. Soaking in a hot tub can relieve pain from muscle spasms and help strengthen movements. Massage improves circulation, helps the patient relax, relieves pain and muscle spasms, and reduces swelling. Very low-level electrical currents applied through the skin stimulate muscles and make them contract, helping paralyzed or weakened muscles to respond again. (TheFreeDictionary.com,