The correct answer is 1 - subacromial bursitis. Repetitive shoulder movements cause a reactive accumulation of fluid within the bursa to attenuate friction. Bursitis usually has a swift onset of extremely severe shoulder pain with dramatic tenderness localized to the insertion of the deltoid at the upper middle third of the anterolateral proximal arm. This contrasts with the more diffuse involvement found with impingement of the supraspinatus or biceps tendon. Given the history of overhead activity, inflammatory arthritis can be ruled out.