A sprain is an injury to the ligaments and similar tissues around a joint. Usually a sprain involves stretching, tearing or partial rupture of the ligaments. It can cause swelling, pain, and instability around the joint. While this can also mean that a bone is broken, sprains can cause similar symptoms. Strains are Muscle Injuries Strains occur in muscles.
Skeletal muscles pull on ligaments and tendons to cause movement.
If the muscle is over-stretched, it can tear, causing a strain. Pain, worse with motion, and swelling often accompany a strain.