Three-dimensional impact kinetics with foot-strike manipulations during running  

作　　者：Andrew D. Nordin Janet S. Dufek John A. Mercer 

机构地区：[1]Department of Kinesiology and Nutrition Sciences, University of Nevada, Las Vegas, NV 89154, USA

出　　处：《Journal of Sport and Health Science》2017年第4期489-497,共9页运动与健康科学（英文）

基　　金：funded by the Institutional Development Award Network of Biomedical Research Excellence through the National Institute of General Medical Sciences (8 20 GM103440-11)

摘　　要：Background: Lack of an observable vertical impact peak in fore/mid-foot running has been suggested as a means of reducing lower extremity impact forces, although it is unclear if impact characteristics exist in other axes. The purpose of the investigation was to compare three-dimensional(3 D) impact kinetics among foot-strike conditions in over-ground running using instantaneous loading rate–time profiles.Methods: Impact characteristics were assessed by identifying peak loading rates in each direction(medial–lateral(ML), anterior–posterior(AP),vertical, and 3 D resultant) following foot-strike instructions(fore-foot, mid-foot, subtle heel, and obvious heel strike). Kinematic and kinetic data were analyzed among 9 male participants in each foot-strike condition.Results: Loading rate peaks were observed in each direction and foot-strike condition, differing in magnitude by direction(3 D resultant and vertical > AP > ML, p ≤ 0.031) and foot-strike: ML(fore-foot and mid-foot strike > obvious heel strike, p ≤ 0.032), AP(fore-foot and mid-foot strikes > subtle-heel and obvious heel strikes, p ≤ 0.023). In each direction, the first loading rate peak occurred later during heel strike running relative to fore-foot(p ≤ 0.019), with vertical and 3 D resultant impact durations exceeding shear(ML and AP, p ≤ 0.007) in each condition.Conclusion: Loading rate–time assessment identified contrasting impact characteristics in each direction and the 3 D resultant following foot-strike manipulations, with potential implications for lower extremity structures in running.Background： Lack of an observable vertical impact peak in fore/mid-foot running has been suggested as a means of reducing lower extremity impact forces, although it is unclear if impact characteristics exist in other axes. The purpose of the investigation was to compare three-dimensional （3D） impact kinetics among foot-strike conditions in over-ground running using instantaneous loading rate-time profiles. Methods： Impact characteristics were assessed by identifying peak loading rates in each direction （medial-lateral （ML）, anterior-posterior （AP）, vertical, and 3D resultant） following foot-strike instructions （fore-foot, mid-foot, subtle heel, and obvious heel strike）. Kinematic and kinetic data were analyzed among 9 male participants in each foot-strike condition. Results： Loading rate peaks were observed in each direction and foot-strike condition, differing in magnitude by direction （3D resultant and vertical 〉 AP 〉 ML, p ≤ 0.031） and foot-strike： ML （fore-foot and mid-foot strike 〉 obvious heel strike, p ≤ 0.032）, AP （fore-foot and mid-foot strikes 〉 subtle-heel and obvious heel strikes, p ≤ 0.023）. In each direction, the first loading rate peak occurred later during heel strike running relative to fore-foot （p ≤ 0.019）, with vertical and 3D resultant impact durations exceeding shear （ML and AP, p ≤ 0.007） in each condition. Conclusion： Loading rate-time assessment identified contrasting impact characteristics in each direction and the 3D resultant following foot-strike manipulations, with potential implications for lower extremity structures in running.

关 键 词：Fore-foot Heel strike Loading rate Mid-foot Overground RESULTANT 

分 类 号：G804.6[文化科学—运动人体科学]