Pain during squatting is better for ruling in or ruling out PFPS?

Pain during squatting is better for ruling in or ruling out PFPS?

• A. Ruling in
• B. Ruling out
• C. Both
• D. Neither

Answer: (B)

The key idea here is how we use provocative findings to judge a diagnosis. A sign or test that is highly sensitive is good for ruling out a condition when the result is negative, whereas a sign that is highly specific is good for ruling in when the result is positive. Pain during squatting reflects loading of the patellofemoral joint, which PFPS typically worsens. However, many other knee problems can also cause pain with deep knee flexion, so this finding alone isn’t specific enough to confirm PFPS. If squatting is pain-free, PFPS is unlikely, because the pattern of pain with deep flexion isn’t present. That makes pain during squatting a better option to rule out PFPS when the test is negative, rather than to rule it in when it’s positive. In practice, PFPS is diagnosed by a combination of history, symptoms, and a cluster of tests, not by a single sign.

The key idea here is how we use provocative findings to judge a diagnosis. A sign or test that is highly sensitive is good for ruling out a condition when the result is negative, whereas a sign that is highly specific is good for ruling in when the result is positive.

Pain during squatting reflects loading of the patellofemoral joint, which PFPS typically worsens. However, many other knee problems can also cause pain with deep knee flexion, so this finding alone isn’t specific enough to confirm PFPS. If squatting is pain-free, PFPS is unlikely, because the pattern of pain with deep flexion isn’t present. That makes pain during squatting a better option to rule out PFPS when the test is negative, rather than to rule it in when it’s positive. In practice, PFPS is diagnosed by a combination of history, symptoms, and a cluster of tests, not by a single sign.