Purpose:This study evaluated the angular kinematic and moment of the ankle and foot during shod walking and barefoot walking in individuals with unilateral chronic ankle instability(CAI).Methods:Recreational soccer pl...Purpose:This study evaluated the angular kinematic and moment of the ankle and foot during shod walking and barefoot walking in individuals with unilateral chronic ankle instability(CAI).Methods:Recreational soccer players with unilateral CAI were recruited for this cross sectional study conducted between January and August 2019.A total of 40 participants were screened for eligibility but only 31 met the inclusion criteria based on the methods of Delahunt et al and Gribble et al.Except for 3 participants not attending the evaluation session,28 participants were finally included.A three dimensional motion analysis system made up of ProReflex motion capture unit and an AMTIb Kistler force plate,embedded in the middle of nine meter walkway,were used to assess the ankle and foot angles and moment during shod walking and barefoot walking conditions.A Statistical Package for Social Sciences(version 20.0)was used to analyze data.Results:During shod walking,the ankle joint plantar-flexion range of motion(ROM)at 10%of the gait cycle(GC)and dorsiflexion ROM at 30%of the GC were significantly higher than those during barefoot walking for both feet(p=0.001,0.001,0.027,and 0.036 respectively).The inversion ROM during shod walking was significantly higher than that during barefoot walking for both feet at 10%and 30%of the GC(p=0.001.0.001,0.001,and 0.042 respectively).At 10%of the GC,the eversion moment was significantly higher between barefoot and shod walking for both feet(both p=0.001).At 30%of the GC,there was no significant difference between shod and barefoot walking plantar-flexion moment of both feet(p=0.975 and 0.763 respectively),and the eversion moment of both feet(p=0.116 and 0.101 respectively).Conclusion:At the early stance,shod walking increases the ankle plantar-flexion and foot inversion ROM,and decreases the eversion moment for both feet in subjects with unilateral CAI.Therefore,the foot wearing condition should be considered during evaluation of ankle and foot kinematics and kinetics.展开更多
Barefoot running is increasing in popularity within the running community, yet the biomechanical differences compared to traditional shod running are not well understood. This study investigates the changes in spinal ...Barefoot running is increasing in popularity within the running community, yet the biomechanical differences compared to traditional shod running are not well understood. This study investigates the changes in spinal dynamics during the gait cycle of runners wearing traditional running shoes (shod) compared to those wearing no shoes (barefoot). Pedal force distribution, kyphotic angle, lordotic angle, and trunk inclination were measured during shod and barefoot gait at three different speeds on a treadmill. Subjects were examined using the DIERS Formetric 4D system and DIERS Pedoscan system. While running barefoot, pedal force distribution analysis showed that 21.0% more force load goes through the forefoot vs. a 10.2% increase in forefoot force with shod (p = 0.0006). At 8.0 km·h-1 the average kyphotic angle was 1.6 degrees greater under barefoot conditions vs. shod conditions (p = 0.008). At 8.0 km·h-1 the average lordotic angle was 0.8 degrees greater under barefoot conditions vs. shod conditions (p = 0.05). Trunk inclination was 0.6 degrees and 0.8 degrees greater under barefoot conditions compared to shod conditions at natural speeds (p = 0.005) and 8.0 km·h-1 (p = 0.015), respectively. Barefoot runners show an increased force load in the forefoot, eliciting a forefoot strike pattern while running barefoot compared to shod running, and it was also found that barefoot runners have reduced trunk inclination. These dynamic changes allow for a more spring-like effect for barefoot runners creating a less transient and slower rise in force. In contrast, a heel strike pattern yields a rapid and high impact collision between heel and ground. As a result, barefoot running translates into less stress on the joints of the lower extremity and back and therefore less risk of injury.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
Inadequate safety shoe wearing is thought to be responsible of many musculoskeletal disorders. A new concept of unstable footwear is proposed to reduce mechanical stresses during work. Major expectations argue for a b...Inadequate safety shoe wearing is thought to be responsible of many musculoskeletal disorders. A new concept of unstable footwear is proposed to reduce mechanical stresses during work. Major expectations argue for a better ankle dynamic behavior leading to an increased muscular activity. The aim of this study was to evaluate the variation of stance characteristics while walking on level ground as a function of the models of safety shoes. Twenty healthy males (aged 23.6 ± 7) were asked to make six gait cycles on a walking track while barefoot, shod with low cost safety footwear, high cost one, and equipped by Masa? Barefoot Technology shoes (the most unstable footwear). Stance phases (heel strike, flat foot and toe-off) have been normalized as percentages of the maximum value of ground reaction force recorded during each step. The highest significant percentages have been observed in Masa? Barefoot Technology shoes condition and only during heel strike (8% to 10.1% higher) and toe-off (10% to 11.3% higher). In contrast, the temporal durations of the three stance phases were not significantly different between the four conditions. The convexity of safety shoe induces less stability increasing the adaptation of the muscle activity of the wearer at heel-strike and toe-off in order to regain stable gait pattern.展开更多
Backgound:Barefoot(BF) running has recently increased in popularity with claims that it is more natural and may result in fewer injuries due to a reduction in impact loading.However,novice BF runners do not necessaril...Backgound:Barefoot(BF) running has recently increased in popularity with claims that it is more natural and may result in fewer injuries due to a reduction in impact loading.However,novice BF runners do not necessarily immediately switch to a forefoot strike pattern.This may increase mechanical parameters such as loading rate,which has heen associated with certain running-related injuries,specifically,tibial stress fractures.patellofemoral pain,and plantar iasciitis.The purpose of this study was to examine changes in loading parameters between typical shod running and instructed BF running with real-time force feedback.Methods:Forty-nine patients seeking treatment for a lower extremity injury ran on a force-sensing treadmill in their typical shod condition and then BF at the same speed.While BF they received verbal instruction and real-time feedback of vertical ground reaction forces.Results:While 92%of subjects(n = 45) demonstrated a rearfoot strike pattern when shod,only 2%(n = 1) did during the instructed BF run.Additionally,while BF 47%(n = 23) eliminated the vertical impact transient in all eight steps analyzed.All loading variables of interest were significantly reduced from the shod to instructed BF condition.These included maximum instantaneous and average vertical loading rates of the ground reaction force(p 【 0.0001),stiffness during initial loading(p 【 0.0001).and peak medial(p = 0.001) and lateral(p 【 0.0001) ground reaction forces and impulses in the vertical(p 【 0.0001).medial(p = 0.047),and lateral(p 【 0.0001) directions.Conclusion:As impact loading has been associated with certain running-related injuries,instruction and feedback on the proper forefoot strike pattern may help reduce the injury risk associated with transitioning to BF running.展开更多
This paper examines the origin,compilation,and circulation of A Barefoot Doctor’s Manual(Chijiao yisheng shouce赤脚医生手册),exploring the relationship between medical politics and knowledge transmission in China,and...This paper examines the origin,compilation,and circulation of A Barefoot Doctor’s Manual(Chijiao yisheng shouce赤脚医生手册),exploring the relationship between medical politics and knowledge transmission in China,and its impact on the promotion of Chinese medicine across the world.Barefoot doctors were a special group of rural medical practitioners active in a very special socio-political context.Various editions of barefoot doctor manuals and textbooks were published across China after the first publication of the Manual in 1969.The publication of these manuals and textbooks became an indelible hallmark of the“Cultural Revolution”(1966–1976),when political publications predominated.The Manual was not only a guide for barefoot doctors in their daily study and practice,but also a primary source of medical knowledge for ordinary people.In the middle of the 1970s,the Manual was translated into many languages and published worldwide.This paper argues that the publication of A Barefoot Doctor’s Manual embodied a public-oriented mode of knowledge transmission that emerged and was adopted during a very specific era,and though it was eventually substituted by a mode of training embedded in the formal medical education system,it demonstrated the impact of politics on medicine and health in the context of resource scarcity and low literacy.Changes in China’s geopolitical status,the West’s pursuit of alternative approaches to medicine and health,and the World Health Organization’s(WHO’s)concern over health universality and equity all contributed to the translation and circulation of the Manual,facilitating the dissemination of Chinese medicine worldwide.The paper thus presents empirical and theoretical contributions to research on the relationship between medical politics and knowledge transmission in China.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
Barefoot slips contribute to over 37% of recurrent fall-related injuries across all age groups.To study slip risk across a wide range of flooring conditions,slip meters with barefoot surrogates(i.e.,sensors,as per AST...Barefoot slips contribute to over 37% of recurrent fall-related injuries across all age groups.To study slip risk across a wide range of flooring conditions,slip meters with barefoot surrogates(i.e.,sensors,as per ASTM standard nomenclature)such as animal skins and rubbers have been used to date,which exhibit biomechanical and frictional properties widely different from the barefoot human skin.Development of a surrogate which can accurately simulate the human heel skin properties would be immensely beneficial for realistic assessment of barefoot slipping risk.A novel surrogate was developed using 3D scanning and printing,and biomimetics,which precisely simulates the biomechanical and frictional properties of the barefoot human heel skin.Mechanical slip testing was conducted with this surrogate on three common bathroom floorings and with six different contaminants.Coefficient of Friction(COF)results similar to human slipping experiments,high repeatability and reproducibility across wet and oily flooring conditions,were confirmed through experiments with the developed heel skin surrogate.The heel skin surrogate would be an indispensable model for accurate estimation of barefoot risk against slips and falls in bathrooms,bathtubs,and swimming pools.展开更多
文摘Purpose:This study evaluated the angular kinematic and moment of the ankle and foot during shod walking and barefoot walking in individuals with unilateral chronic ankle instability(CAI).Methods:Recreational soccer players with unilateral CAI were recruited for this cross sectional study conducted between January and August 2019.A total of 40 participants were screened for eligibility but only 31 met the inclusion criteria based on the methods of Delahunt et al and Gribble et al.Except for 3 participants not attending the evaluation session,28 participants were finally included.A three dimensional motion analysis system made up of ProReflex motion capture unit and an AMTIb Kistler force plate,embedded in the middle of nine meter walkway,were used to assess the ankle and foot angles and moment during shod walking and barefoot walking conditions.A Statistical Package for Social Sciences(version 20.0)was used to analyze data.Results:During shod walking,the ankle joint plantar-flexion range of motion(ROM)at 10%of the gait cycle(GC)and dorsiflexion ROM at 30%of the GC were significantly higher than those during barefoot walking for both feet(p=0.001,0.001,0.027,and 0.036 respectively).The inversion ROM during shod walking was significantly higher than that during barefoot walking for both feet at 10%and 30%of the GC(p=0.001.0.001,0.001,and 0.042 respectively).At 10%of the GC,the eversion moment was significantly higher between barefoot and shod walking for both feet(both p=0.001).At 30%of the GC,there was no significant difference between shod and barefoot walking plantar-flexion moment of both feet(p=0.975 and 0.763 respectively),and the eversion moment of both feet(p=0.116 and 0.101 respectively).Conclusion:At the early stance,shod walking increases the ankle plantar-flexion and foot inversion ROM,and decreases the eversion moment for both feet in subjects with unilateral CAI.Therefore,the foot wearing condition should be considered during evaluation of ankle and foot kinematics and kinetics.
文摘Barefoot running is increasing in popularity within the running community, yet the biomechanical differences compared to traditional shod running are not well understood. This study investigates the changes in spinal dynamics during the gait cycle of runners wearing traditional running shoes (shod) compared to those wearing no shoes (barefoot). Pedal force distribution, kyphotic angle, lordotic angle, and trunk inclination were measured during shod and barefoot gait at three different speeds on a treadmill. Subjects were examined using the DIERS Formetric 4D system and DIERS Pedoscan system. While running barefoot, pedal force distribution analysis showed that 21.0% more force load goes through the forefoot vs. a 10.2% increase in forefoot force with shod (p = 0.0006). At 8.0 km·h-1 the average kyphotic angle was 1.6 degrees greater under barefoot conditions vs. shod conditions (p = 0.008). At 8.0 km·h-1 the average lordotic angle was 0.8 degrees greater under barefoot conditions vs. shod conditions (p = 0.05). Trunk inclination was 0.6 degrees and 0.8 degrees greater under barefoot conditions compared to shod conditions at natural speeds (p = 0.005) and 8.0 km·h-1 (p = 0.015), respectively. Barefoot runners show an increased force load in the forefoot, eliciting a forefoot strike pattern while running barefoot compared to shod running, and it was also found that barefoot runners have reduced trunk inclination. These dynamic changes allow for a more spring-like effect for barefoot runners creating a less transient and slower rise in force. In contrast, a heel strike pattern yields a rapid and high impact collision between heel and ground. As a result, barefoot running translates into less stress on the joints of the lower extremity and back and therefore less risk of injury.
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.
文摘Inadequate safety shoe wearing is thought to be responsible of many musculoskeletal disorders. A new concept of unstable footwear is proposed to reduce mechanical stresses during work. Major expectations argue for a better ankle dynamic behavior leading to an increased muscular activity. The aim of this study was to evaluate the variation of stance characteristics while walking on level ground as a function of the models of safety shoes. Twenty healthy males (aged 23.6 ± 7) were asked to make six gait cycles on a walking track while barefoot, shod with low cost safety footwear, high cost one, and equipped by Masa? Barefoot Technology shoes (the most unstable footwear). Stance phases (heel strike, flat foot and toe-off) have been normalized as percentages of the maximum value of ground reaction force recorded during each step. The highest significant percentages have been observed in Masa? Barefoot Technology shoes condition and only during heel strike (8% to 10.1% higher) and toe-off (10% to 11.3% higher). In contrast, the temporal durations of the three stance phases were not significantly different between the four conditions. The convexity of safety shoe induces less stability increasing the adaptation of the muscle activity of the wearer at heel-strike and toe-off in order to regain stable gait pattern.
文摘Backgound:Barefoot(BF) running has recently increased in popularity with claims that it is more natural and may result in fewer injuries due to a reduction in impact loading.However,novice BF runners do not necessarily immediately switch to a forefoot strike pattern.This may increase mechanical parameters such as loading rate,which has heen associated with certain running-related injuries,specifically,tibial stress fractures.patellofemoral pain,and plantar iasciitis.The purpose of this study was to examine changes in loading parameters between typical shod running and instructed BF running with real-time force feedback.Methods:Forty-nine patients seeking treatment for a lower extremity injury ran on a force-sensing treadmill in their typical shod condition and then BF at the same speed.While BF they received verbal instruction and real-time feedback of vertical ground reaction forces.Results:While 92%of subjects(n = 45) demonstrated a rearfoot strike pattern when shod,only 2%(n = 1) did during the instructed BF run.Additionally,while BF 47%(n = 23) eliminated the vertical impact transient in all eight steps analyzed.All loading variables of interest were significantly reduced from the shod to instructed BF condition.These included maximum instantaneous and average vertical loading rates of the ground reaction force(p 【 0.0001),stiffness during initial loading(p 【 0.0001).and peak medial(p = 0.001) and lateral(p 【 0.0001) ground reaction forces and impulses in the vertical(p 【 0.0001).medial(p = 0.047),and lateral(p 【 0.0001) directions.Conclusion:As impact loading has been associated with certain running-related injuries,instruction and feedback on the proper forefoot strike pattern may help reduce the injury risk associated with transitioning to BF running.
文摘This paper examines the origin,compilation,and circulation of A Barefoot Doctor’s Manual(Chijiao yisheng shouce赤脚医生手册),exploring the relationship between medical politics and knowledge transmission in China,and its impact on the promotion of Chinese medicine across the world.Barefoot doctors were a special group of rural medical practitioners active in a very special socio-political context.Various editions of barefoot doctor manuals and textbooks were published across China after the first publication of the Manual in 1969.The publication of these manuals and textbooks became an indelible hallmark of the“Cultural Revolution”(1966–1976),when political publications predominated.The Manual was not only a guide for barefoot doctors in their daily study and practice,but also a primary source of medical knowledge for ordinary people.In the middle of the 1970s,the Manual was translated into many languages and published worldwide.This paper argues that the publication of A Barefoot Doctor’s Manual embodied a public-oriented mode of knowledge transmission that emerged and was adopted during a very specific era,and though it was eventually substituted by a mode of training embedded in the formal medical education system,it demonstrated the impact of politics on medicine and health in the context of resource scarcity and low literacy.Changes in China’s geopolitical status,the West’s pursuit of alternative approaches to medicine and health,and the World Health Organization’s(WHO’s)concern over health universality and equity all contributed to the translation and circulation of the Manual,facilitating the dissemination of Chinese medicine worldwide.The paper thus presents empirical and theoretical contributions to research on the relationship between medical politics and knowledge transmission in China.
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.
文摘Barefoot slips contribute to over 37% of recurrent fall-related injuries across all age groups.To study slip risk across a wide range of flooring conditions,slip meters with barefoot surrogates(i.e.,sensors,as per ASTM standard nomenclature)such as animal skins and rubbers have been used to date,which exhibit biomechanical and frictional properties widely different from the barefoot human skin.Development of a surrogate which can accurately simulate the human heel skin properties would be immensely beneficial for realistic assessment of barefoot slipping risk.A novel surrogate was developed using 3D scanning and printing,and biomimetics,which precisely simulates the biomechanical and frictional properties of the barefoot human heel skin.Mechanical slip testing was conducted with this surrogate on three common bathroom floorings and with six different contaminants.Coefficient of Friction(COF)results similar to human slipping experiments,high repeatability and reproducibility across wet and oily flooring conditions,were confirmed through experiments with the developed heel skin surrogate.The heel skin surrogate would be an indispensable model for accurate estimation of barefoot risk against slips and falls in bathrooms,bathtubs,and swimming pools.
