Which of the following conditions is commonly associated with muscle issues?

Polymyositis is indeed the correct choice associated with muscle issues, as it is an inflammatory condition specifically targeting the muscles. This disease leads to muscle weakness, particularly in the proximal muscles of the body, which are those closest to the trunk. Individuals with polymyositis often experience difficulty with tasks that require muscle strength, such as climbing stairs, lifting objects, or even lifting their arms. The muscle inflammation in this condition can result from autoimmune processes, where the body mistakenly attacks its own muscle fibers.

The other conditions listed typically have different primary effects. Sarcoidosis, while it can involve muscles, primarily affects the lungs and lymph nodes, presenting with granulomas. Osteoarthritis primarily affects the joints, leading to pain and stiffness due to cartilage degeneration rather than direct muscle issues. Rheumatoid arthritis is an autoimmune disorder that mainly affects the joints as well, causing pain, swelling, and potential joint damage but not predominantly muscle weakness like polymyositis. Thus, polymyositis stands out as the condition most directly linked to significant muscle-related problems.