Effect of genu recurvatum on the anterior cruciate ligament-deficient knee during gait.

PURPOSE: This study aimed to investigate the effects of genu recurvatum, which is considered to carry a high risk for anterior cruciate ligament (ACL) injury, on healthy and post-ACL injury gait and lower extremity muscle strength.

METHODS

Subjects were 36 patients with ACL-deficient knee and 40 healthy controls without pain or restricted range of motion of the lower extremity during gait. The knee joints of all subjects were examined; those with over 10° hyperextension of both knees were defined as exhibiting genu recurvatum. On this basis, the subjects were further subdivided into two groups: with or without genu recurvatum. A three-dimensional motion analysis system and force plates were used for gait analysis. Isokinetic dynamometers were used to measure knee muscle strength.

RESULTS

There were no differences in joint angles, joint moments, or components of ground reaction force during gait or in knee strength for the healthy control subjects with and without genu recurvatum. ACL-deficient subjects without genu recurvatum showed a decrease in knee angles during the stance phase and a decrease in extension moments during the early stance phase compared with ACL-deficient subjects with genu recurvatum and controls. In contrast, neither knee angles nor extension moments during the stance phase differed significantly between ACL-deficient subjects with genu recurvatum and controls.

CONCLUSIONS

This study provides clinically relevant information regarding the effects of genu recurvatum on gait parameters. The results suggest that in ACL injuries, the presence of genu recurvatum alters gait pattern. Consideration of the presence of genu recurvatum would be useful during rehabilitation following ACL injuries or ACL reconstruction. LEVEL OF EVIDENCE: II. Prospective comparative study.