Role of hyperpronation as a possible risk factor for anterior cruciate ligament injuries.

OBJECTIVE: The purpose of this study was to examine the relationship between hyperpronation and the occurrence of noncontact injury to the anterior cruciate ligament (ACL). DESIGN AND SETTING: Subjects were categorized as either ACL injured (ACLI) or ACL uninjured (ACLU). All ACLI subjects received their injuries from a noncontact mechanism. To justify using the ACLI subjects' uninjured legs as representative of their preinjury state, a t test was used to compare the differences between the left and right foot for the ACLU group on both measurements. Based on the results of the t test, a regression analysis was performed to determine whether group membership could be predicted from navicular drop. All measures were performed in a university athletic training room. SUBJECTS: Fourteen ACLI subjects (age = 21.07 +/- 0.83 yr, ht = 174.81+/-8.29 cm, wt = 72.32+/-13.47 kg) and 14 ACLU subjects (age = 21.14+/-2.03 yr, ht = 177.35+/-11.31 cm, wt = 72.99+/-14.81 kg) participated. MEASUREMENTS: Hyperpronation was assessed via the navicular drop test and the calcaneal stance test. RESULTS: No significant difference (p > .05) between feet for the navicular drop test was found. However, there was a significant difference (p < .05) between feet for the calcaneal stance test, and, thus, this measure was not used in the regression analysis. Using the navicular drop score, the regression analysis was unable to predict group membership. CONCLUSIONS: Hyperpronation as measured by the navicular drop test was not a predictor of ACL injury, and, thus, may not be a predisposing factor to noncontact ACL injuries.