The Journal of Bone and Joint Surgery

Image Quiz
Pain and Weakness of the Shoulder in a Young Man¹
A thirty-two-year-old right-handed male landscaper and snowplow operator went to his primary-care physician with a one-month history of pain, a feeling of heaviness, and positional weakness in the right shoulder. He was treated with limitation of activity, nonsteroidal anti-inflammatory medication, and shoulder exercises for five months, but the symptoms did not improve.
Physical examination, performed six months after the onset of symptoms, revealed isolated weakness of external rotation of the shoulder with slight atrophy of the infraspinatus muscle. Electromyography revealed selective partial denervation of the infraspinatus muscle, and nerve-conduction studies showed evidence of delayed conduction to the infraspinatus muscle, indicating nerve entrapment.
Magnetic resonance imaging was performed.
Fig. 1	An axial T2-weighted fast-spin-echo image is shown in Figure 1. H = humeral head C = coracoid process S = scapular spine For larger view, click on image
Two abnormal structures are present (arrows).