| Summary: | 碩士 === 國立臺北教育大學 === 體育學系碩士班 === 97 === Objective: The aim of this study is an experimental evaluation comparison of the mechanism for the joint angles of low limbs which regulate transference and landing tactics during a barefoot landing to the surface of three different hardness materials from a height of 40 centimeters between different genders. Methods: For this work, 10 female students and 10 male students from the department of physical education (age, 19.6±0.82 years, height, 166.15±8.29 centimeters, weight, 60.05±6.95 kilograms) participated in this study. A Mega speed 25k high speed camera (100Hz), an AMTI force plate (1000Hz), a Biovision 50g accelerometer (1000Hz) and four Biovision EMG system (1000Hz) are used to synchronously capture kinematical , dynamics and lower limbs EMG parameters of landing. The film undergoes Kwon3D movement analysis and human limb sections of parameter organizational system and Direct Linear Transformation in order to possess the physical parameters. The primitive signal from the force plate is processed by DasyLab 6.0 software, low-pass filtering (10Hz) and calibrates modular to calculate the primitive three dimension counterforce, and then obtain the impulse value through integration analysis. The primitive signals of EMG is processed by DasyLab 6.0 software, band-pass filtering, low-pass filtering (10Hz) and full-wave rectification, also obtain the integration EMG through integration analysis. Moreover, the greater EMG in the landing action is regarded as the basis for standardization (100%). Finally, the resulting data undergoes two-way ANOVA via SPSS 12.0 statistics software. The level of significance for this experiment is set to α=.05. Result: In different genders, the angles of hip joint, knee joint and ankle joint, displacement, the greatest angular velocities, the peak vertical reaction force, the greater loading rate and the 50ms passive impulse. They all reduce when the materials of ground surface soften. Furthermore, the appearance of peak postpones similarly when the materials of ground surface soften. On the time of landing, M. biceps femoris and M. tibialis cranialis react. After the heels land completely, the beforehand activation of M. rectus femoris increase to reduce vibration. Under the interaction between gender and surface material, only the displacement of knee joint angles and the vibration value of knee joint achieve remarkable difference. Thus, it illustrates an undeniable fact that landing on different materials, female has a relatively wider bended knee joint angles but male has a comparatively higher vibration value of knee angle. Conclusion: During landing on different hardness materials, to reduce friction while landing relies on the action of low limb joint. It is therefore advisable that both sexes should increase the banded angles of hip joint, knee joint and ankle joint in advance through training to decrease the rate of injury to low limb. Furthermore, wearing protective apparatus on the joints can reduce vibration harm of knee joint. Beside, soft surface material contributes to prolong buffering time and decrease the huge friction while landing.
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