ارزیابی مفصل اصلی طی هاپینگ

Abstract

The lower limb musculoskeletal behaves like spring during bouncing repetitive movement such as jogging, running and hopping with certain value of stiffness (1). Controversy exists on the contribution of the lower extremity joint on regulating leg stiffens during hopping. Studies have found ankle or knee joint to significantly impact the adjustments made for leg stiffness frequency (2.2Hz) (1). The results of experimental studies and computer modeling have mainly found that ankle as the main effector of hopping mechanics (2). However, significant correlations have been found between the knee and leg stiffness during freely chosen frequency and during maximal hopping (3). Arampatzis et al. (4) reported that during drop jump knee stiffness has a substantial contribution to the leg stiffness. Moreover, it has been proposed that knee joint has primary role in adjusting of leg stiffness during running. Based on these findings, there are still some conflicts regarding the primary joint involved in regulating leg stiffness and hopping mechanics. We hypnotized that the primary joint during hopping could be selected as important component by PCA. The aim of this study was to assess the primary joint during hopping.