Acromioclavicular Joint Injuries
The acromioclavicular (AC) joint (the connection between the collar bone and the shoulder blade) is commonly injured as a result of either a direct force to the tip of the shoulder or through an indirect force sustained during a fall on an outstretched hand. This resultant force results in disruption to the capsule and ligaments that supports the bony architecture of the AC joint. The patient with an acute AC joint injury will typically cradle the involved arm against the body with the uninvolved hand for support. This posture helps to decrease the pull of the weight of the arm against the ligamentous and capsular tissues that have been disrupted.
Adhesive Capsulitis (Frozen Shoulder)
This condition involves stiffening (freezing) and inflammation of the soft tissues (joint capsule and ligaments) that surround the shoulder joint. The stiffening of these structures creates severe loss of functional shoulder movement, pain surrounding the joint, and an inability to sleep on the affected side.
Anterior Shoulder Dislocation
This injury typically occurs as a direct result of trauma to the ligaments and capsular tissues that surround the ball and socket (glenohumeral joint) of the shoulder. Some common mechanisms of injury include being hit behind the arm while the shoulder is positioned in an overhead throwing motion and falling onto an outstretched arm. This condition contributes to a sense of instability in the shoulder combined with an inability to perform certain daily activities and sports. Those who experience a shoulder dislocation are typically evaluated by a physician for reduction and to rule out fracture or cartilage (glenoid labrum) damage.
Rotator Cuff Tendonitis
This condition is often associated with repetitive, abnormal stress to the tendons of the rotator cuff (four small muscles that surround and steer shoulder movement) resulting in inflammation and pain. Rotator cuff tendonitis may cause sharp, acute pain in the shoulder or upper arm aggravated after periods of activity such as overhead throwing or lifting. Pain may also be experienced when dressing, grooming, sleeping on the affected shoulder, reaching high over head, or behind the back. Functional weakness is usually present with lifting during everyday activities (especially between waist and shoulder height). If the condition is left untreated, the tendonitis may progress to a partial thickness tear of the rotator cuff, often requiring surgery.
Rotator Cuff Impingement
This condition involves a progressive, mechanical impingement of the rotator cuff tendons beneath the bony architecture (coracoacromial arch) of the shoulder joint. The resultant impingement of the cuff tendons results in significant shoulder pain increased with the performance of overhead and functional activities. Common causes of cuff impingement include bony abnormalities and rotator cuff tendon thickening.
Rotator Cuff Tear
This condition involves complete (full thickness) or incomplete (partial thickness) disruption of the tendons of the rotator cuff muscle group. Common causes of injury include direct trauma to the shoulder, repetitive overhead lifting, and participation in sports that require overhead throwing. In addition to these causes, some patients experience a cuff tear simply as a direct result of a degenerative process with no specific trauma or activity associated with the injury. A common presentation for a patient with a rotator cuff tear includes lateral shoulder pain affecting the ability to sleep accompanied with functional weakness limiting his or her ability to lift the arm against gravity.
Superior Labrum Anterior & Posterior
This condition involves injury to the superior (top) portion of the labrum of the shoulder joint. The labrum is a cartilaginous ring that serves to deepen the socket of the joint providing both stability and a site for muscular attachment for the biceps brachii. Common causes of a SLAP lesion include falling onto an outstretched hand, overhead lifting, and overhead throwing. Common complaints include instability within the shoulder causing a vague ache. In addition, some patients may report catching, popping, or clicking within the joint during functional activities.