A 45-year-old manual laborer presents with chronic pain in his right shoulder. The pain worsens when he lifts heavy objects at work. On examination, there's tenderness over the acromioclavicular (AC) joint, and pain is elicited when cross-body adduction of the arm is performed. What is the likely diagnosis, and what are the next steps?
This patient's symptoms suggest an AC joint sprain, often referred to as "weightlifter's shoulder" or "AC joint arthritis". This condition results from chronic overuse and strain on the joint. Initial management should include rest, ice, over-the-counter pain relievers, and potentially a brief period of immobilization. If these measures don't alleviate symptoms, further interventions such as physical therapy, corticosteroid injections, or surgery may be considered.