The effect of increasing running speed on three-dimensional changes of lower limb joint kinematics in open kinetics chain and swing phase

Running is known as one of the most popular sports. Due to lifestyle changes and limitations of time and space, the use of treadmills for walking and running has increased. However, the biomechanical differences in coordination between running on a treadmill at different speeds have not been sufficiently addressed. The aim of this study was to investigate the effect of increasing running speed on three-dimensional changes of lower extremity joint angles in the open kinetics chain and swing phase. ۲۸ elite runners participated in this study. Subjects ran on a equipped treadmill while kinematics of running data were recorded for ۳۰ seconds through a three-dimensional ۱۲-camera motion recording system at speeds of ۲.۵, ۳.۵ and ۴.۵ m/s. Data were normalized based on the subjects body mass as well as ۱۰۱ time points in the running cycle. Swing phase were capture according to the ground reaction force by force plate data were the magnitude were recorded as zero. The normality and homogeneity of variance of the dependent variable hypotheses were tested using Bartlett and Levens tests. Repeated measurement test was employed to measure the angles of the Hip, knee and ankle of the dominant t joints in the running swing phase. In the hip and knee joint, there were significant differences between all three speeds of ۲.۵ m/s, ۳.۵ m/s and ۴.۵ m/s on all planes. Also, there was no significant difference in ankle joint in any of the speeds in all directions. Changes in the angle of the hip and knee joints are significantly greater as the running speed increases. Due to the fact that high-speed running reduces the stability of the body, the central nervous system commands to increase the range of motion of the hip and knee joints to regulate the structure of the body and reduce instability in response to disorders. Also, the ankle joint, as the closest joint in contact with the ground, is less adaptable to changes in running speed to act as a solid foundation for maintaining the body s dynamic balance.

کلیدواژه ها:

Running ، Swing Phase ، kinematics ، Lower limb