Background Heel-height difference has been used to detect subtle knee flexion contractures, but the effects of thigh circumference differences and patient positioning during testing have not been evaluated. Hypothesis Differences in thigh circumference measurements and whether the patient's patellae are on or off the examination table during heel-height difference measurement will not affect the accuracy of detecting knee flexion contracture. Study Design Prospective cohort study. Methods Bilateral knee range of motion, prone heel-height difference with the patellae on and off the table, and thigh circumference at 5 and 15 cm proximal to the proximal pole of the patella were measured by one investigator on 50 consecutive patients who had undergone unilateral anterior cruciate ligament reconstruction. Results A high degree of correlation was demonstrated between the heel-height difference and the standard range of motion measurement. Differences in thigh girth and patellar position did not statistically affect the accuracy of the heel-height difference as an indicator of knee flexion contracture. Conclusion Heel-height difference is a valid method of documenting knee flexion contractures. Compared with traditional goniometer assessment, this test is a more meaningful and easier way for detecting subtle knee flexion contractures of less than 10°.
Artificial Intelligence-Based Assessment System for Evaluating Suitable Range of Heel Height
