Clinical perspective
A practical approach to shoulder pain Because there are numerous structures that can cause shoulder pain, it is helpful if the clinician can narrow the problem down into one or more of the following ‘categories' of shoulder pain; (i) the rotator cuff, (ii) instability, (iii) the AC joint, (iv) referred pain. Furthermore, the clinician must seek predisposing factors for the injury that is diagnosed. Careful clinical assessment can often go a long way to achieving both of these goals. Before explaining the key features of the history and physical examination, we provide a brief overview of the four common categories of shoulder pain listed above.
Injuries to the rotator cuff muscles and tendons may be acute, chronic, or acute on chronic. Acute injuries include muscle strains and partial or complete tendon tears. Overuse injuries include tendinopathy and tightening and focal thickening of the muscle bellies. An example of an acute on chronic injury is a complete rotator cuff tendon tear in a previously degenerative tendon. Athletes with rotator cuff tendon injuries frequently present with shoulder impingement.
Shoulder instability is another common cause of shoulder pain. Pain resulting from instability may be due to sprains of the anterior shoulder capsule or secondary impingement as well as acute subluxation and dislocation. Glenoid labral lesions may occur either as an acute injury or as a result of overuse. Instability may be obvious clinically in patients who are having recurrent episodes of dislocation or subluxation. In many cases, however, instability may initially cause relatively minor symptoms such as mild impingement.
It is important to assess the AC joint in an athlete presenting with shoulder pain. The athlete may complain of shoulder pain and assume that the injury is from the glenohumeral joint itself.
The shoulder is a common site for referral of pain from the cervical spine, the upper thoracic spine and associated soft tissues, especially the trapezius, levator scapulae and rotator cuff muscles. In the patient with chronic shoulder problems, there are usually a number of factors contributing to the pain. Cervical and thoracic joint dysfunction, soft tissue tightness and trigger points are often present in addition to primary shoulder joint pathology such as rotator cuff tendinopathy and/or instability.
As with any sporting injury it is important to identify, and subsequently correct, any predisposing factors. Predisposing factors to the development of shoulder injuries include abnormal biomechanics (Chapter 5) such as poor throwing technique or faulty swimming style, stiffness of the lower cervical and upper thoracic spines or muscle imbalance and weakness, especially rotator cuff weakness and weakness of the scapular stabilizing muscles. It is essential to consider the whole kinetic chain as any deficiency in the chain, e.g. stiff lumbar spine, puts additional stress on distal parts of the chain, e.g. rotator cuff.
Diagnosis of shoulder pain in the athlete requires taking a thorough history, examination and investigation. A list of possible causes of shoulder pain is shown in Table 14.2.
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