Author/Authors :
Yin, Lulu Department of Critical Care Medicine - Shanghai Tenth People’s Hospital - School of Medicine - Tongji University, Shanghai, China , Hu, Xiaoyue School of Kinesiology - Shanghai University of Sport, Shanghai, China , Lai, Zhangqi School of Kinesiology - Shanghai University of Sport, Shanghai, China , Liu, Kun Department of Rehabilitation Medicine - Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, China , Wang, Lin School of Kinesiology - Shanghai University of Sport, Shanghai, China
Abstract :
Foot strike patterns influence the running efficiency and may be an injury risk. However, differences in the leg stiffness between runners with habitual forefoot (hFFS) and habitualrearfoot (hRFS) strike patterns remain unclear. This study aimed at determining the differences in the stiffness, associated loading rate, and kinematic performance between runners with hFFS and hRFS during running. Kinematic and kinetic data were collected amongst 39 runners with hFFS and 39runners with hRFS running at speed of 3.3 m/s, leg stiffness (Kleg), and vertical stiffness (Kvert), and impact loads werecalculated. Results found that runners with hFFS had greater Kleg (P=0:010,Cohen’sd=0:60), greater peak vertic alground reaction force (vGRF) (P=0:040,Cohen’sd=0:47), shorter contact time(tc)(P<0:001,Cohen’sd=0:85), and smaller maximum leg compression (ΔL)(P=0:002,Cohen’sd=0:72) compared with their hRFS counterparts. Runnerswith hFFS had lower impact peak (IP) (P<0:001,Cohen’sd=1:65), vertical average loading rate (VALR) (P<0:001,Cohen’sd=1:20), and vertical instantaneous loading rate (VILR) (P<0:001,Cohen’sd=1:14) compared with runners with hRFS. Runner swith hFFS landed with a plantar flexed ankle, whereas runners with hRFS landed with a dorsiflexed ankle (P<0:001,Cohen’sd=3:35). Runners with hFFS also exhibited more flexed hip (P=0:020,Cohen’sd=0:61) and knee (P<0:001,Cohen’sd=1:15)than runners with hRFS at initial contact. These results might indicate that runners with hFFS were associated with better running economy through the transmission of elastic energy.
