The purposes of this study were to explore the biomechanical variations of vertical jump performance in well-trained young group before and after passive static stretching (PSS) of knee flexors muscles and to further discuss how the passive static stretching (PSS) influences vertical jump performance in order to provide a more effective warm-up routine and theoretical basis for physical education (PE) teachers and coaches. 15 male middle school students without any injury histories on lower limbs in the past 3 months were included in this study. Subjects with markers on the lower limbs performed vertical jump performance before and immediately after PSS of knee flexors muscles, respectively. A Vicon motion capture system was used to collect the kinematic data of lower limb and Kistler force platform simultaneously recorded the ground reaction force (GRF) during vertical jump. Significant differences were also found in the kinematics part. In sagittal plane, the hip, knee and ankle highest flexion angles were greater after PSS when take-off (hip: p< 0.05; knee: p< 0.01; ankle: p< 0.05); while the hip and knee highest flexion angles were greater before PSS when landing (hip: p< 0.01; knee: p< 0.05). These results showed that the increased range of motion (ROM) of hip, knee, and ankle because of PSS could boost the explosive extension of lower limb during take-off, which can potentially improve vertical jump performance, although the peak value of GRF after PSS was lower. Therefore, the PSS applied only on knee flexors muscles may have an acute effect on enhancing the vertical jump performance for well-trained young group and should be added to warm-up exercises in middle school sports class and sports training.

Abstract. Moxibustion has been known by more and more people as a traditional Chinese treatment technique. Although the mechanism of moxibustion is not clear, the therapeutic effect of moxibustion is obvious to all. The purpose of this paper is to investigate whether moxibustion can alleviate the fatigue state after the movement of human body by means of biomechanics testing. Therefore, analysis of hip, knee and ankle kinematics during forefoot landing from a vertical jump and comparison of moxibustion treatment versus no treatment could identify further evidence of its practicality when dealing with exercise induced fatigue. The joint angle and the angular velocity of the joint were obtained from Vicon motion anakysis system, and peak vGRF and time was measure with Kistler. Overall, it can be concluded that moxibustion can have a direct effect on a UK citizens vertical jump lower limb kinematics during a fatigued state. This was particularly evident within the significant differences between peak knee angle during the take-off phase and peak ankle angle during the take-off and landing phases. Furthermore, statistically significant differences between the vertical jumps angular velocity of the knee and hip joints provide further evidence that moxibustion treatments physiological adaptations can alter and improve vertical jump biomechanics. Moreover, not only did moxibustion treatment improve peak angles and angular velocity, statistically significant differences in jump time were evident providing further evidence that moxibustion can in fact improve fatigued individuals jumping kinematics, but there is no significant different in peak vGRF. Evidence from these results could perhaps suggest that moxibustion could be used as an injury preventative measure to reduce fatigue and aid performance. Further investigation with a larger sample size and perhaps an alternative control is required to further validate these findings.