Background:This prospective study explored the effects of endurance running(ER) in minimal versus standard running shoes on the foot’s superficial layer intrinsic muscles and the function of the longitudinal arch.Our...Background:This prospective study explored the effects of endurance running(ER) in minimal versus standard running shoes on the foot’s superficial layer intrinsic muscles and the function of the longitudinal arch.Our hypothesis was that running in minimal shoes would cause hypertrophy in these muscles and lead to higher,stronger,stiffer arches.Methods:The hypothesis was tested using a sample of 33 healthy runners randomized into two groups,a control group shod in traditional running footwear and an experimental group shod in minimal support footwear,whose feet were scanned in an MRI before and after a 12-week training regime.Running kinematics as well as arch stiffness and height were also assessed before and after the treatment period.Results:Analysis of anatomical cross-sectional areas and muscle volumes indicate that the flexor digitomm brevis muscle became larger in both groups by 11%and 21%,respectively,but only the minimally shod runners had significant areal and volumetric increases of the abductor digiti minimi of 18%and 22%,respectively,and significantly increased longitudinal arch stiffness(60%).Conclusion:These results suggest that endurance running in minimal support footwear with 4 mm offset or less makes greater use of the springlike function of the longitudinal arch,thus leading to greater demands on the intrinsic muscles that support the arch,thereby strengthening the foot.展开更多
Background:Forefoot strike(FFS) and rearfoot strike(RFS) runners differ in their kinematics,force loading rates,and joint loading patterns,but the timing of their muscle activation is less clear.Methods:Forty recreati...Background:Forefoot strike(FFS) and rearfoot strike(RFS) runners differ in their kinematics,force loading rates,and joint loading patterns,but the timing of their muscle activation is less clear.Methods:Forty recreational and highly trained runners ran at four speeds barefoot and shod on a motorized treadmill. "Barefoot" runners wore thin,five-toed socks and shod runners wore neutral running shoes.Subjects were instructed to run comfortably at each speed with no instructions about foot strike patterns.Results:Eleven runners landed with an FFS when barefoot and shod and eleven runners landed with an RFS when barefoot and shod.The 18remaining runners shifted from an FFS when barefoot to an RFS when shod(shifters).Shod shifters ran with a lower stride frequency and greater stride length than all other runners.All FFS runners landed with more plantarflexed ankles and more vertical lower legs at the beginning of stance compared to RFS runners.FFS runners activated their plantarflexor muscles 1 1%earlier and 10%longer than RFS runners.Conclusion:This earlier and longer relative activation of the plantarrlexors likely enhances the capacity for the passive structures of the foot and ankle to store elastic energy,and may also enhance the performance of the active muscle by increasing the storage of elastic strain energy in the cross-bridaes and activated thin.展开更多
Background:Investigations of running gait among barefoot and populations have revealed a diversity of foot strike behaviors,with some preferentially employing a rearfoot strike(RFS) as the foot touches down while othe...Background:Investigations of running gait among barefoot and populations have revealed a diversity of foot strike behaviors,with some preferentially employing a rearfoot strike(RFS) as the foot touches down while others employ a midfoot strike(MFS) or forefoot strike(FFS).Here,we report foot strike behavior and joint angles among traditional Hadza hunter-gatherers living in Northern Tanzania.Methods:Hadza adults(n = 26) and juveniles(n = 14) ran at a range of speeds(adults:mean 3.4 ± 0.7 m/s,juveniles:mean 3.2 ± 0.5 m/s) over an outdoor trackway while being recorded via high-speed digital video.Foot strike type(RFS.MFS.or FFS) and hind limb segment angles at foot strike were recorded.Results:Hadza men preferentially employed MFS(86.7%of men),while Hadza women and juveniles preferentially employed RFS(90.9%and85.7%of women and juveniles,respectively).No FFS was recorded.Speed,the presence of footwear(sandals vs.barefoot),and trial duration had no effect on foot strike type.Conclusion:Unlike other habitually barefoot populations which prefer FFS while running.Hadza men preferred MFS.and Hadza women and juveniles preferred RFS.Sex and age differences in foot strike behavior among Hadza adults may reflect differences in running experience,with men learning to prefer MFS as they accumulate more running experience.展开更多
Purpose:This study examined variation in foot strike types,lower extremity kinematics,and arch height and stiffness among Tarahumara Indians from the Sierra Tarahumara.Mexico.Methods:High speed video was used to study...Purpose:This study examined variation in foot strike types,lower extremity kinematics,and arch height and stiffness among Tarahumara Indians from the Sierra Tarahumara.Mexico.Methods:High speed video was used to study the kinematics of 23 individuals.13 who habitually wear traditional minimal running sandals(huaraches).and 10 who habitually wear modern,conventional running shoes with elevated,cushioned heels and arch support.Measurements of foot shape and arch stiffness were taken on these individuals plus an additional sample of 12 individuals.Results:Minimally shod Tarahumara exhibit much variation with 40%primarily using midfoot strikes,30%primarily using forefoot strikes,and30%primarily using rearfoot strikes.In contrast,75%of the conventionally shod Tarahumara primarily used rearfoot strikes,and 25%primarily used midfoot strikes.Individuals who used forefoot or midfoot strikes landed with significantly more plantarflexed ankles,flexed knees,and flexed hips than runners who used rearfoot strikes.Foot measurements indicate that conventionally shod Tarahumara also have significantly less stiff arches than those wearing minimal shoes.Conclusion:These data reinforce earlier studies that there is variation among foot strike patterns among minimally shod runners,but also support the hypothesis that foot stiffness and important aspects of running form,including foot strike,differ between runners who grow up using minimal versus modem,conventional footwear.展开更多
Background:Numerous studies about the interaction between footwear(and barefoot) and kinematic and kinetic outcomes have been published over the last few years.Recent studies however lead to the conclusion that the as...Background:Numerous studies about the interaction between footwear(and barefoot) and kinematic and kinetic outcomes have been published over the last few years.Recent studies however lead to the conclusion that the assumed interactions depend mainly on the subjects" experience of barefoot(BF) walking/running,the preferred running strike pattern,the speed,the hardness of the surface,the thickness of the midsole material,and the runners’ level of ability.The aim of the present study was to investigate lower leg kinematics o\’ BF running and running in minimal running shoes(MRS) to assess comparability of BF kinematics in both conditions.To systematically compare both conditions we monitored the influencing variables described above in our measurement setup.We hypothesized that running in MRS does not alter lower leg kinematics compared to BF running.Methods:Thirty-seven subjects,injury-free and active in sports,ran BF on an EVA foam runway,and also ran shod wearing Nike Free 3.0 on a tartan indoor track.Lower-leg 3D kinematics was measured to quantify rearfoot and ankle movements.Skin markers were used in both shod and BF running.Results:All runners revealed rearfoot strike pattern when running barefoot.Differences between BF and MRS running occurred particularly during the initial stance phase of running,both in the sagittal and the frontal planes.BF running revealed a flatter foot placement,a more plantar flexed ankle joint and less inverted rearfoot at touchdown compared to MRS running.Conclusion:BF running does not change the landing automatically to forefoot running,especially after a systematic exclusion of surface and other influencing factors.The Nike Free 3.0 mimics some BF features.Nevertheless,changes in design of the Nike Free should be considered in order to mimic BF movement even more closely.展开更多
Background:Previous studies of foot strike patterns of distance runners in road races have typically found that the overwhelming majority of shod runners initially contact the ground on the rearfoot.However,none of th...Background:Previous studies of foot strike patterns of distance runners in road races have typically found that the overwhelming majority of shod runners initially contact the ground on the rearfoot.However,none of these studies has attempted to quantify foot strike patterns of barefoot or minimally shod runners.This study classifies foot strike patterns of barefoot and minimally shod runners in a recreational road race.Methods:High-speed video footage was obtained of 169 barefoot and 42 minimally shod distance runners at the 2011 New York City Barefoot Run.Foot strike patterns were classified for each runner,and frequencies of forefoot,midfoot,and rearfoot striking were compared between the barefoot and minimally shod groups.Results:A total of 59.2%of barefoot runners were forefoot strikers,20.1%were midfoot strikers,and 20.7%were rearfoot strikers.For minimally shod runners,33.3%were forefoot strikers,19.1%were midfoot strikers,and 47.6%were rearfoot strikers.Foot strike distributions for barefoot and minimally shod runners were significantly different both from one another and from previously reported foot strike distributions of shod road racers.Conclusion:Foot strike patterns differ between barefoot and minimally shod runners,with forefoot striking being more common,and rearfoot striking less common in the barefoot group.展开更多
基金supported by the Charles Phelps Taft Research Center at the University of Cincinnati
文摘Background:This prospective study explored the effects of endurance running(ER) in minimal versus standard running shoes on the foot’s superficial layer intrinsic muscles and the function of the longitudinal arch.Our hypothesis was that running in minimal shoes would cause hypertrophy in these muscles and lead to higher,stronger,stiffer arches.Methods:The hypothesis was tested using a sample of 33 healthy runners randomized into two groups,a control group shod in traditional running footwear and an experimental group shod in minimal support footwear,whose feet were scanned in an MRI before and after a 12-week training regime.Running kinematics as well as arch stiffness and height were also assessed before and after the treatment period.Results:Analysis of anatomical cross-sectional areas and muscle volumes indicate that the flexor digitomm brevis muscle became larger in both groups by 11%and 21%,respectively,but only the minimally shod runners had significant areal and volumetric increases of the abductor digiti minimi of 18%and 22%,respectively,and significantly increased longitudinal arch stiffness(60%).Conclusion:These results suggest that endurance running in minimal support footwear with 4 mm offset or less makes greater use of the springlike function of the longitudinal arch,thus leading to greater demands on the intrinsic muscles that support the arch,thereby strengthening the foot.
基金the Purves Summer Research AwardSherman Fairchild Foundation+1 种基金National Science Foundation (NSF-0634592)Howard Hughes Medical Institute Undergraduate Science Program award 52006301 to Harvey Mudd College
文摘Background:Forefoot strike(FFS) and rearfoot strike(RFS) runners differ in their kinematics,force loading rates,and joint loading patterns,but the timing of their muscle activation is less clear.Methods:Forty recreational and highly trained runners ran at four speeds barefoot and shod on a motorized treadmill. "Barefoot" runners wore thin,five-toed socks and shod runners wore neutral running shoes.Subjects were instructed to run comfortably at each speed with no instructions about foot strike patterns.Results:Eleven runners landed with an FFS when barefoot and shod and eleven runners landed with an RFS when barefoot and shod.The 18remaining runners shifted from an FFS when barefoot to an RFS when shod(shifters).Shod shifters ran with a lower stride frequency and greater stride length than all other runners.All FFS runners landed with more plantarflexed ankles and more vertical lower legs at the beginning of stance compared to RFS runners.FFS runners activated their plantarflexor muscles 1 1%earlier and 10%longer than RFS runners.Conclusion:This earlier and longer relative activation of the plantarrlexors likely enhances the capacity for the passive structures of the foot and ankle to store elastic energy,and may also enhance the performance of the active muscle by increasing the storage of elastic strain energy in the cross-bridaes and activated thin.
基金the National Science Foundation(BCS-0850815)Hunter College
文摘Background:Investigations of running gait among barefoot and populations have revealed a diversity of foot strike behaviors,with some preferentially employing a rearfoot strike(RFS) as the foot touches down while others employ a midfoot strike(MFS) or forefoot strike(FFS).Here,we report foot strike behavior and joint angles among traditional Hadza hunter-gatherers living in Northern Tanzania.Methods:Hadza adults(n = 26) and juveniles(n = 14) ran at a range of speeds(adults:mean 3.4 ± 0.7 m/s,juveniles:mean 3.2 ± 0.5 m/s) over an outdoor trackway while being recorded via high-speed digital video.Foot strike type(RFS.MFS.or FFS) and hind limb segment angles at foot strike were recorded.Results:Hadza men preferentially employed MFS(86.7%of men),while Hadza women and juveniles preferentially employed RFS(90.9%and85.7%of women and juveniles,respectively).No FFS was recorded.Speed,the presence of footwear(sandals vs.barefoot),and trial duration had no effect on foot strike type.Conclusion:Unlike other habitually barefoot populations which prefer FFS while running.Hadza men preferred MFS.and Hadza women and juveniles preferred RFS.Sex and age differences in foot strike behavior among Hadza adults may reflect differences in running experience,with men learning to prefer MFS as they accumulate more running experience.
基金a grant from the American School of Prehistoric Research (Harvard University)
文摘Purpose:This study examined variation in foot strike types,lower extremity kinematics,and arch height and stiffness among Tarahumara Indians from the Sierra Tarahumara.Mexico.Methods:High speed video was used to study the kinematics of 23 individuals.13 who habitually wear traditional minimal running sandals(huaraches).and 10 who habitually wear modern,conventional running shoes with elevated,cushioned heels and arch support.Measurements of foot shape and arch stiffness were taken on these individuals plus an additional sample of 12 individuals.Results:Minimally shod Tarahumara exhibit much variation with 40%primarily using midfoot strikes,30%primarily using forefoot strikes,and30%primarily using rearfoot strikes.In contrast,75%of the conventionally shod Tarahumara primarily used rearfoot strikes,and 25%primarily used midfoot strikes.Individuals who used forefoot or midfoot strikes landed with significantly more plantarflexed ankles,flexed knees,and flexed hips than runners who used rearfoot strikes.Foot measurements indicate that conventionally shod Tarahumara also have significantly less stiff arches than those wearing minimal shoes.Conclusion:These data reinforce earlier studies that there is variation among foot strike patterns among minimally shod runners,but also support the hypothesis that foot stiffness and important aspects of running form,including foot strike,differ between runners who grow up using minimal versus modem,conventional footwear.
文摘Background:Numerous studies about the interaction between footwear(and barefoot) and kinematic and kinetic outcomes have been published over the last few years.Recent studies however lead to the conclusion that the assumed interactions depend mainly on the subjects" experience of barefoot(BF) walking/running,the preferred running strike pattern,the speed,the hardness of the surface,the thickness of the midsole material,and the runners’ level of ability.The aim of the present study was to investigate lower leg kinematics o\’ BF running and running in minimal running shoes(MRS) to assess comparability of BF kinematics in both conditions.To systematically compare both conditions we monitored the influencing variables described above in our measurement setup.We hypothesized that running in MRS does not alter lower leg kinematics compared to BF running.Methods:Thirty-seven subjects,injury-free and active in sports,ran BF on an EVA foam runway,and also ran shod wearing Nike Free 3.0 on a tartan indoor track.Lower-leg 3D kinematics was measured to quantify rearfoot and ankle movements.Skin markers were used in both shod and BF running.Results:All runners revealed rearfoot strike pattern when running barefoot.Differences between BF and MRS running occurred particularly during the initial stance phase of running,both in the sagittal and the frontal planes.BF running revealed a flatter foot placement,a more plantar flexed ankle joint and less inverted rearfoot at touchdown compared to MRS running.Conclusion:BF running does not change the landing automatically to forefoot running,especially after a systematic exclusion of surface and other influencing factors.The Nike Free 3.0 mimics some BF features.Nevertheless,changes in design of the Nike Free should be considered in order to mimic BF movement even more closely.
文摘Background:Previous studies of foot strike patterns of distance runners in road races have typically found that the overwhelming majority of shod runners initially contact the ground on the rearfoot.However,none of these studies has attempted to quantify foot strike patterns of barefoot or minimally shod runners.This study classifies foot strike patterns of barefoot and minimally shod runners in a recreational road race.Methods:High-speed video footage was obtained of 169 barefoot and 42 minimally shod distance runners at the 2011 New York City Barefoot Run.Foot strike patterns were classified for each runner,and frequencies of forefoot,midfoot,and rearfoot striking were compared between the barefoot and minimally shod groups.Results:A total of 59.2%of barefoot runners were forefoot strikers,20.1%were midfoot strikers,and 20.7%were rearfoot strikers.For minimally shod runners,33.3%were forefoot strikers,19.1%were midfoot strikers,and 47.6%were rearfoot strikers.Foot strike distributions for barefoot and minimally shod runners were significantly different both from one another and from previously reported foot strike distributions of shod road racers.Conclusion:Foot strike patterns differ between barefoot and minimally shod runners,with forefoot striking being more common,and rearfoot striking less common in the barefoot group.
