Your 35-year-old female patient presents with left anterior…
Your 35-year-old female patient presents with left anterior knee pain for 4 weeks after starting a new running program. Pain is worse when going downstairs, squatting, or standing up from a chair, and eases slightly with rest. She describes a dull ache around the patellar region. No numbness, tingling, or swelling reported. PMH: None. Social history: Works in retail; enjoys running 3x/week. Functional limitations: Difficulty climbing stairs, squatting, and running. Which muscles’ performance are most important to test? Why?