Muscle strains in the hip area occur when a stretched muscle is forced to contract suddenly. A fall or direct blow to the muscle, or overstretching and overuse can tear muscle fibers, resulting in a strain. The risk of muscle strain increases with prior injury to the area, improper warm up before exercising or attempting to do too much too quickly. Strains may be mild, moderate or severe, depending on the extent of the injury.
Tendonitis (also known as tendinitis or tenonitis) is a general term used to describe inflammation associated with a tendon. Tendons connect muscles to bone, and inflammation of these rope-like tissues is the most common cause of soft-tissue pain. Tendonitis differs from arthritis, which refers to inflammation of a joint. The onset of tendonitis can usually be attributed to overuse of the associated area. With age, repetitive motion can injure the tendon where it attaches to the bone, promoting an inflammatory response by the body. This inflammation can cause “pain on motion,” swelling, warmth, tenderness, and redness. This latter symptom is called “erythema” and refers to the dilation of small surface blood vessels, capillaries as a result of the inflammatory process.