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 ax...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.展开更多
基金funded by the Institutional Development Award Network of Biomedical Research Excellence through the National Institute of General Medical Sciences(820 GM103440-11)
文摘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.
