摘要：The purpose of the current study was to examine the effects of an intensive stretch shortening-cycle (SSC) protocol (100 plyometric jumps) on knee kinematics during running on a treadmill in healthy children using 3D kinematics. Twelve healthy and untrained children volunteered. Their mean + age, height and weight was 10,1±0,5 years, 142± 6,1 cm and 37 ±4,6kg, respectively. Muscle damage of lower extremities was caused by 100 maximal intensity plyometric jumps performed as 10 sets of 10 continuous jumps with a 30 second restperiod between sets. Muscle damage indicators [delayed onset muscle soreness (DOMS), knee-joint flexion/extension angles during running on a treadmill (speed at 2.8 m/s)] were assessed pre-, 0h, 24h, 48h and 72h post exercise. Kinematic data were captured at 100 Hz using a six-camera 3D motion analysis system (VICON 612). Repeated measures one-way ANOVA with five levels were utilised for the parameters. Allmuscle damage indicators revealed significant changes post- compared to pre-exercise data (p<0.05). Kinematic analysis revealed that the 100 plyometric jumps decreased knee-joint angles at different phases of stance (impact, support, push-off phase). These changes were more evident just after (0h) the protocol and 48h after this, and remained till 72h post at a great extent (p<0.05). Lastly, children suffered from delayed muscle soreness on their thigh muscles which remained only 24 hours after this (p<0.05). Muscle damage causesalterations in treadmill running in knee kinematics of untrained children probable due to differentiation of their central nervous system running strategy
