Biomechanical Analysis of the Lower Extremity during a Drop Landing Task in Senior Primary School Students

• Main Authors: Liang, Heng-Yi, 梁恆毅
• Other Authors: Wang, Li-I
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/16970936541999659557

碩士 === 國立東華大學 === 體育與運動科學系 === 99 === Purpose:This study will focus mainly on the differences between ground reaction force and lower extremity stiffness adjustment by the study of drop landing task. Specifically, this analysis will further to compare the characteristics of lower extremity during drop landing between male and female senior primary school students. Methods: Subjects must not have been participated in any sports-related team at school, and those who have been injured in the lower limbs during the past six months will be eliminated from this research. Finally, 11 male students and 10 female students from both Ming Yih and Chung Yuan Primary School in Hualien are the qualified study group. They will be asked to drop from a stage which is 40 cm above the ground and two-footed landing symmetrically. The AMTI force plate and MegaSpeed high speed camera were time-synchronized. Kwon 3D motion analysis system and KwonGRF system will be used. All data were analyzed using the individual t-test to evaluate whether the test variable differed significantly between the two groups. The significance level was set at α = 0.05. The data were analyzed using the Statistical Program for Social Sciences 17.0 for Windows package program. Results: The male students had a significantly larger knee angle upon initial foot contact with the ground, a significantly larger knee flexion angle, and a larger CG downward displacement during landing in comparison to female students. The male students had a significantly larger second peak value of vertical GRF in comparison to female students. The duration from initial foot-ground contact to the second peak vertical GRF appeared was significantly shorter in the male students in comparison to the female students. The male students had a significantly larger passive impulse, loading rate, and vertical stiffness in comparison to the female students. Conclusions: In the drop landing task from 40-cm drop height we infer that: 1. senior male students have a higher risk of lower extremity injury during landing; 2. at the instant of landing, male students are generally landed with a straight-standing position to increase the landing impact; 3. senior female students have a smaller vertical stiffness, this characteristic might to reduce the landing impact.