Muscles help you move, and also support all the bones and joints in your body. Many aches and pains can be prevented or treated by having strong muscles. If your muscles are strong, they can protect your joints and keep your posture aligned properly. Proper posture will limit any abnormal strain on your joints, ligaments, muscles, tendons and bones.
If you have had an injury to your bones, muscles, or structures in and around your joints, a physical therapist can help teach you what strengthening exercises are helpful and what exercises are harmful. They can monitor your exercises when you first start and then make sure that other problems do not develop. A physical therapist can also teach you how much weight to lift, the number of repetitions, sets and when to progress or change your exercises.