Execution
- 1Position the patient sitting or supine with both knees visible for comparison.
- 2Ask the patient to actively flex and extend the knee through the available range.
- 3Observe patellar tracking, tibiofemoral alignment, swelling, guarding, crepitus, extension lag, and side-to-side range difference.
- 4Ask the patient to actively medially and laterally rotate the tibia when the knee is flexed and rotation is clinically relevant.
- 5Record pain location, movement quality, end-range limitation, and whether repeated or loaded motion reproduces the history.
Positive outcome
Abnormal findings: pain, loss of motion, altered patellar tracking, extension lag, swelling-related guarding, or asymmetry.
Expected range- Flexion 135°–150°
- Extension 0° (hyperextension up to 5°–10° in some people)
Loss of active extension may reflect effusion, quadriceps inhibition, extensor mechanism injury, or intra-articular block. Symptoms often appear only with weight bearing, so loaded functional testing may be needed.
CommentAROM is a screening and comparable-sign test, not a diagnosis. Magee emphasizes observing patellar position, dynamic tracking, and ability to achieve full extension. Loaded functional testing may be needed because symptoms often appear only with weight bearing.
Low Clinical Value