Relationship Between Weightbearing Ankle Dorsiflexion Passive Range of Motion and Ankle Kinematics During Gait

Background: Measurement of weightbearing ankle dorsiflexion (DF) passive range of motion (PROM) has been suggested as a way to estimate ankle kinematics during gait; however, no previous study has demonstrated the relationship between ankle DF during gait and ankle DF PROM with knee extension. We examine the relationship between maximum ankle DF during gait and nonweightbearing and weightbearing ankle DF PROM with knee extension. Methods: Forty physically active individuals (mean +/- SD age, 21.63 +/- 1.73 years) participated in this study. Ankle DF PROM with knee extension was measured in the nonweightbearing and weightbearing conditions; maximum ankle DF during gait was assessed using a three-dimensional motion analysis system. The relationship between each variable was calculated using the Pearson product moment correlation coefficient, and the difference in ankle DF PROM between the nonweightbearing and weightbearing conditions was analyzed using a paired t test. Results: The weightbearing measurement (r = 0.521; P,.001) for ankle DF PROM showed a greater correlation with maximum ankle DF during gait than did the nonweightbearing measurement (r = 0.245; P =.029). Ankle DF PROM was significantly greater in the weightbearing than in the nonweightbearing condition (P<.001) despite a significant correlation between the two measurements (r = 0.402; P<.001). Conclusions: These findings indicate that nonweightbearing and weightbearing measurements of ankle DF PROM with knee extension should not be used interchangeably and that weightbearing ankle DF PROM with the knee extended is more appropriate for estimating ankle DF during gait.