健康儿童膝关节屈伸工作时的生物力学规律.docVIP

健康儿童膝关节屈伸工作时的生物力学规律* 翟凤鸣，李 立，崔巴特尔，李壮志，陈玉娟 Biodynamics rule of flexion and extension work of the knee joints in healthy children Zhai Feng-ming, Li Li, Cui Bater, Li Zhuang-zhi, Chen Yu-juan Abstract BACKGROUND: There are few studies on isokinetic muscle strength test in children. OBJECTIVE: To discuss the biomechanical work of flexion and extension of knee joints in healthy children through the test of knee flexion and extension strength. DESIGN, TIME AND SETTING: The control experiment was performed at the Sports Laboratory of Hebei Normal University from October to December 2006. PARTICIPANTS: A total of 66 healthy children, including 31 boys and 35 girls, aged about 10 years old, were enrolled in this study at the elementary schools of Shijiazhuang city. METHODS: Using the Kinitech Isokinetic testing system (Kylingk, Australia), isokinetic muscle strength test was conducted to measure flexion and extension strength of knee joints according to 3 different angular velocities: 60, 120 and 240 (°)/s. MAIN OUTCOME MEASURES: The comparison of peak torque (PT) value and maximum power of flexion and extension in boys and girls. RESULTS: PT value declined with the speed increase, while maximum power increased at the three different test. PT value of left side was bigger than right side. The PT ratio of flexion and extension was more than 0.7 and increased with increasing speed. There was no significant difference in comparison of PT value of flexion and extension at speed of 60°/s and 120°/s (P 0.05), while there were significant differences at speed of 240°/s (P 0.01, P 0.05). PT value of left extension was greater in boys than girls (P 0.05). CONCLUSION: The changes in maximum power and peak torque in children show the same trend as the adults. It is indicated that children should develop flexor strength and keep a balance development of flexor and extensor during early physical activity. Zhai FM, Li L, Cui Bater, Li ZZ, Chen YJ. Biodynamics rule of flexion