Shoulder injuries caused by overuse or trauma all have one common symptom: shoulder pain. The pain location and speed of onset give clues as to which disorder has occurred. These may involve the muscles, tendons, bursae, ligaments, bones and/or joints of the rotator cuff.
The interactive parts of the shoulder that create wide-ranging movement, however, are vulnerable to associated injury. According to the American Orthopaedic Society for Sports Medicine (AOSSM), traumatic damage to a bone or joint may harm adjacent nerves and connective tissue as well.
Bursitis
Shoulder stress on the acromioclavicular (AC) joint may inflame the bursa, which are responsible for absorbing shock and lubricating the joint for free movement. The University of Maryland Medical Center notes that this creates symptoms of swelling, redness and heat in the joint area. Shoulder pain can come on suddenly following acute strain, or as a result of chronic repetitive motion.
Tendinitis
Tendinitis has similar causes as bursitis, but creates pain and tenderness that may diffuse across the rotator cuff area rather than just at the AC joint. These tendon strains are common among swimmers and baseball pitchers. The Mayo Clinic reports that gradual onset of shoulder pain with a dull, achy quality arises due to overuse. More sudden and severe symptoms may indicate a tendon rupture.
Muscle Strain
Everyday strains to the rotator cuff muscles can occur when too much force is placed on the area, causing it to "pull" or stretch. University Sports Medicine states that shoulder injuries to muscles may elicit a popping or burning sensation immediately, followed by the onset of pain. Swelling or bruising may be visible and the muscle may become weak and ineffective.
Separated Shoulder
A severe strain to the ligaments that connect the collarbone to the AC joint and shoulder blade can cause some degree of separation of these parts. According to University Sports Medicine, instant shoulder pain and visible deformity indicates a complete tissue tear. Separated shoulder injuries will restrict movement of the rotator cuff, and swelling, bruising and tenderness will arise at the top of the shoulder or end of the collarbone.
Dislocated Shoulder
Shoulder injuries that cause the humerus to pull out of the AC joint socket are termed dislocations. These are caused by a blow to the shoulder or sharp twist to the arm. Visible signs include a large bump on the front or back of the shoulder. The American Orthopaedic Society for Sports Medicine notes that intense pain may be accompanied by muscle spasms, as the local nerves and and muscles are displaced.
