Suprascapular neuropathy in pitchers.

The clinical features and preoperative and postoperative electrodiagnostic studies were reviewed in two professional pitchers with a suprascapular neuropathy. These studies demonstrate that denervation of the infraspinatus and/or supraspinatus muscle is not always due to entrapment of the nerve at the suprascapular or spinoglenoid notches, as is often proposed. Similar studies in healthy pitchers during spring training and again at midseason demonstrate that slowing of suprascapular nerve conduction is detectable in some cases as the season progresses. Sagittal sections of a cadaver with the arm fixed in the acceleration phase of the pitching motion demonstrate five possible sites of trauma to the suprascapular nerve. Mechanisms proposed to explain these progressive, but potentially reversible, changes include consideration of biomechanical factors as well as anatomical features. An alternative hypothesis to nerve trauma that explains this symptom complex is intimal damage to the axillary or suprascapular artery and subsequent production of microemboli which become trapped in the suprascapular nerve vasa nervorum.