kinematics of lower extremity during forward and backward walking on different gradients

Purpose: forward walking (fw) and backward walking (bw) on different gradients of the treadmill is a common exercise for lower extremity rehabilitation. however, limited studies are found about the three-dimensional analysis of lower extremity and status of the knee joint during fw and bw on different gradients. therefore, this study aimed to investigate the lower extremity joints kinematics during fw and bw on incline and decline surfaces. methods: the current research has a quasi-experimental design. sixteen healthy males with the mean (sd) age of 22.4(2.5) years, volunteered to participate in this study. the subjects’ fw and bw with their preferred speed on a treadmill at four gradients (-7.5%, 0%, +5% and +10%), were analyzed by using motion capture system. all data were analyzed using paired sample t test (p<0.05). results: significant differences were seen between fw and bw in most angular variables in sagittal plane. however, there were no significant differences between fw and bw in most parameters of knee angle in frontal plane. conclusion: based on the results, with increase in fw inclination and decrease in bw inclination, the knee varus angle in frontal plane reduces. therefore, fw on the upslope surfaces or bw on downslope surfaces, probably is a suitable solution to reduce the loads exerted on medial compartment of the knee.