Rheumatology and Musculoskeletalcommon
A 67-year-old woman has new bilateral shoulder and hip girdle aching with difficulty lifting her arms and rising from a chair. Symptoms are worst in the morning for 90 minutes, she has no objective muscle weakness, and her creatine kinase is normal. Her C-reactive protein is 74 mg/L (reference range less than 5), with normal calcium and thyroid function. Which is the most likely diagnosis?