서강대학교

초록/요약

Military training includes walking and running on uneven surfaces that are not perfectly level and downhill walking. Many studies, however, have compared only walking down low gradients with walking on level ground, reporting that the risk of anterior cruciate ligament (ACL) injury is likely to be low. The purpose of the present study was (1) to examine knee and ankle kinematic and kinetic changes during downhill walking as the slope angle increased and (2) to evaluate non-contact ACL injury risks by analyzing biomechanical injury risk factors. The primary hypothesis was that the biomechanical ACL risk factors would be greater during downhill walking compared with level walking. Fifteen male subjects performed level walking and 15° and 25° downhill walking. For the kinetic and kinematic parameters, one-way ANOVA tests and paired one- and two-tailed t-tests were performed to determine whether differences were significant at a significance level of 0.05. The peak posterior ground reaction force (0° vs. 15°: p < 0.001; 0° vs. 25°: p < 0.001; 15° vs. 25°: p < 0.001) and the peak knee anterior force and valgus moment (0° vs. 15°: p < 0.001; 0° vs. 25°: p < 0.001) in the early stance phase increased as the slope angle increased. The peak knee valgus and internal tibial rotation moments in the late stance also increased (0° vs. 15°: p < 0.001; 0° vs. 25°: p < 0.001; 15° and 25°: p < 0.001). These results showed that the peak knee anterior force and peak knee valgus moment were greater during downhill walking than during level walking. The combination of knee valgus and internal tibial rotation moment also increased. Therefore, the risk for ACL injuries may be increased during downhill walking with a greater slope angle.