The shoulder complex consists of four joints—the glenohumeral, acromioclavicular (AC), sternoclavicular (SC), and scapulothoracic joints—with encapsulating ligaments and muscles (Figure 8–1). It is the most mobile joint of the body, with the primary role of positioning the hand in space to function. A detailed history and physical examination with appropriate imaging can help narrow the extensive differential diagnosis and guide treatment. Most conditions can be treated initially with medication and physical therapy. Resistant shoulder pain should be referred for orthopedic consultation.
Shoulder and rotator cuff muscle anatomy, frontal (A) and superior (B) views.
Much like pain elsewhere, shoulder pain can be initially categorized by onset of symptoms, character of pain, and what activities relieve and aggravate the pain.
The onset of pain may follow a recent injury (≤4 weeks) or remote injury (>4 weeks). Recent injury usually has an acute onset of pain, whereas a remote injury may be episodic or insidious. Because the shoulder is involved in many repetitive functions, pain can result from overuse.
Character, location, timing, and radiation of pain can also be helpful. Sharp or stabbing pain usually suggests a structural cause. Dull and aching pain, especially related to early mornings and weather changes, suggests arthritis. Burning and radiating pain suggests a neurologic cause. Lateral upper arm pain is typical of rotator cuff pain. Pain radiating below the elbow or to the medial border of the scapula suggests a cervical spine or neurologic source of the pain. Pain at night is also typical of rotator cuff disease, but it can be noted in metastatic bone disease. Pain with overhead activity is a very common symptom and can be generally categorized as “impingement” pain. It is most commonly caused by rotator cuff dysfunction or disease. Constitutional symptoms, such as fever and weight loss, should alert the clinician that the cause of pain is infectious, metabolic, or neoplastic.
Other symptoms associated with shoulder pain include stiffness, weakness, and instability. A helpful way to frame the magnitude of shoulder pain is to identify the activities that are limited by the pain, such as overhead use, lifting, dressing, combing or shampooing hair, washing, and hygiene. Recreational and occupational limitations should also be sought.
For an accurate examination, the shoulder needs to be visible; for female patients, privacy can be respected by using special examination gowns or by having the patient wear a sports bra, swimsuit top, or strapless blouse.
Both shoulders should be examined not only from the front but also from the back and side. Particular attention should be paid to shoulder symmetry to allow the clinician to appreciate subtle muscle atrophy. Atrophy suggests neurologic injury or chronicity of the underlying problem.