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A comparative biomechanical analysis of habitually unshod and shod runners based on a foot morphological difference

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... Further, load is shared between the forefoot and rearfoot, elastic energy is stored in the longitudinal arch (midfoot), and stability is maintained through a gripping function in the toes ( Bramble and Lieberman 2004;Mei et al. 2016). It has been reported that functional performance of the foot is influenced by foot type (Hillstrom et al. 2013;Mootanah et al. 2013), age group ( Müller et al. 2012), ethnicity ( Gurney et al. 2009), shod or barefoot habits ( Mei et al. 2015Mei et al. , 2016Shu et al. 2015;Hollander et al. 2017a), BMI and gender ( Domjanic et al. 2015). ...
... Specifically, habitually barefoot populations with increased hallux abduction * Yaodong Gu guyaodong@hotmail.com presented enhanced load sharing in the forefoot, but this was not observed in shod populations, whom exhibited concentrated pressure to the metatarsals ( Mei et al. 2015). This was confirmed in a recent study whereby the toes were bound to simulate narrow footwear and produced limited load bearing in the toes and increased load in the metatarsals ( Mei et al. 2016). ...
... The slender Caucasian foot showed concentrated pressure in the heel and forefoot, whereas the wider bare Indian foot showed evenly distributed pressure (D'Août et al. 2009). These findings were consistent with a recent study investigating biomechanical differences in Chinese shod and Indian barefoot runners ( Mei et al. 2015). Normalising for differences in ethnicity, comparison of Indian shod and Indian barefoot participants revealed wearing shoes increase the concentration of foot plantar pressure (D'Août et al. 2009). ...
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This study presents population-based multivariate regression models for predicting foot plantar pressure from easily measured foot metrics in both shod and barefoot populations for running and walking tasks. Both shod and barefoot models were trained on 50 participants and predicted plantar pressure from anthropometric measurements using a ‘leave-one-out’ validation with R2 values of 0.72–0.78 across walking and running in both populations. When the model was blindly tested on 16 new data sets, the model performed just as well with R2 values of 0.76–0.79 across both populations. Walking and running peak plantar pressure were predicted with similar levels of accuracy in both populations. It was revealed that forefoot plantar pressure was more sensitive to the hallux-toe distance in barefoot people with shod participants showing little response to this foot characteristic. Lateral forefoot plantar pressure was sensitive to the arch index in both shod and barefoot participants but only for walking. During running, the arch index was not a useful determinant of lateral forefoot pressure. Hence, habitually barefoot people who adopt minimalist footwear should consider additional support in the medial forefoot and walking footwear should include forefoot support stratified by arch index (foot type), but running footwear is challenging due to the variability in strike patterns.
... Methodological aspects of each study are summarized in Figure 2. In 19 studies, 11,15,16,[18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33] ...
... Fourteen studies measured any kinetic variables, such as external moment, impact, and loading rate ( Figure 3C). Considering the GRF, most studies showed the loading rate is higher in barefoot condition, 20,28,31,34,47,48 and the impact peak has opposite results. 22,24 Regarding articular moments, plantar flexion moment was higher in the barefoot condition, 15,16 while knee extension moment was higher in shod condition. ...
... Thirty-three studies analyzed the running kinematics (spatiotemporal parameters or joint kinematics) ( Figures 3A and 3B). Considering spatiotemporal parameters, six studies 30,31,36,41,42,45 showed runners usually hit the ground with the rearfoot when they were wearing shoes, and the other six 17,30,31,36,43,45 showed their participants had hit the ground with the midfoot or forefoot whilst running barefoot. Shod running presented larger stride length, 12,13,15,17,22,24,25,27,28,31,43,44 longer stride time, 14,36,47 longer contact time. ...
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This study aims to analyze and summarize the biomechanical (kinematics, kinetics and neuromuscular) differences between shod and barefoot running, through a literature review. Searches were conducted for complete articles published between 2013 and November 2018 in the Web of Science, PubMed, Scopus and SPORTdiscus databases. The search terms used were Biomechanics, Kinetics, Kinematics, Electromyography, “Surface Electromyography”; and Unshod, Barefoot, Barefeet and Running. The search resulted in 687 articles; after excluding duplicates and selecting by title, abstract and full text, 40 articles were included in the review. The results show that there are important differences in the biomechanics of running when shod or barefoot. In general, studies indicate that in barefoot running: a) individuals present forefoot or midfoot foot strike patterns, while in shod running the typical pattern is the rearfoot strike; (b) greater cadence and shorter stride length are observed; and (c) there is greater knee flexion, lower peak vertical ground reaction force and greater activation of the medial gastrocnemius. In addition, barefoot runners contact the ground with greater plantar flexion, possibly as a strategy to reduce impact when stepping without footwear. These differences, as well as runners’ individual characteristics, should be considered in the prescription of the barefoot running, in order to minimize injuries resulting from the practice. Level of Evidence II; Review.
... The elevated and cushioned heel of the modern running shoe may be a contributory factor that has facilitated the differences in the strike patterns observed. However, strike patterns have been observed to be variant, even between shod or barefoot populations, in recent studies [2,7,8,24]. In spite of the conflicting opinions about barefoot locomotion, it has gained in popularity in recent years, and is now included in athletic training [25], recreational running [26], and rehabilitation [27]. ...
... In spite of the conflicting opinions about barefoot locomotion, it has gained in popularity in recent years, and is now included in athletic training [25], recreational running [26], and rehabilitation [27]. A previous study has revealed the foot shape and function differences in native barefoot walkers [5] and runners [24]. The morphological differences between habitually barefoot and shod runners were found to exist in the forefoot and toe regions [4]. ...
... The test protocol was consistent with a previously reported experiment [23], which was published from our laboratory recently [1,24]. After completion of foot scanning, participants revisited the motion capture lab for experimental vertical jumping and running tests. ...
Article
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Barefoot and shod running has received increased attention in recent years, however, the influence of morphology-related foot function has not been explored. This study aimed to investigate morphology-related jumping and running biomechanical functions in habitually barefoot and shod males. A total of 90 barefoot males (Indians) and 130 shod males (Chinese), with significant forefoot and toe morphology differences, participated in a vertical jump and running test to enable the collection of kinematic and kinetic data. The difference of pressure distribution in the hallux and forefoot was shown while jumping and running. The unrestricted forefoot and toes of the barefoot group presented flexible movement and leverage functions to expand the forefoot loading area during performance of the two tasks. Findings related to morphology functions, especially in the forefoot and toe may provide useful information for footwear design.
... The pressure sensor is positioned parallel to the supporting surface and thus provides a different amount of sensor numbers per area depending on the manufacturers' specification. The sensor number by the [27]. The critical point is that the number of sensors and platform sizes could contribute different accuracy readings on the regions of interests. ...
... The advantage is that the subject could use natural gait during the experiment to avoid the troubles of platform targeting [29]. Hence, it suits both indoor or outdoor uses on daily habitual or wider range of sports motion activities since the pressure-sensing device is portable within the shoes or socks [27,30]. The utilization of inshoe pressure system is much useful when analyzing the ergonomics of footwear or foot deformities. ...
... The sampling rate frequency provided on each system is measured by cycle per second (frames per second) or Hertz (Hz). The range is as low as 25 Hz [49] to as high as 1000 Hz [27] for both systems either the plantar or in-shoe system. The higher the sampling rate frequency, the more accurate will be the measured data. ...
Article
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The science of foot pressure studies the forces acting on the bottom and different regions of the foot along with the pressure exerted on the plantar surface with the interacting surface in contact. The information derived gave impact to human biomechanical assessment on body balance and ergonomics posture during gait. Various experiments designed at generating foot pressure data returns only with limited knowledge generated. Obviously, the procedure for experiment design needs to be properly understood from the foot morphology aspects; healthiness, footwear, surface in contact, load and forces impacts, and the foot sensitivity as well as the specification for the foot pressure. This paper reviews the proper preliminary experimental setups for foot pressure measurement analysis during static or dynamic gait. The strength and limitations of recent devices used and considerable variables are also discussed. The overall review explains that the comfortable natural gait in relation to the aspects of sensitivity, load, time duration, and stability are the standard considerations for plantar pressure experiments.
... Habitually barefoot runner and shod runner existed biomechanical difference during barefoot jogging and running [10,20]. In sagittal ROM, they had similar lower-limb flexion-extension trajectory, but SR had the larger range than BR. ...
... In sagittal ROM, they had similar lower-limb flexion-extension trajectory, but SR had the larger range than BR. These results reflected that habitually shod runner under barefoot condition showed the highest joint flexion angle [10]. Some studies pointed that the lower-limb joint flexion angle was associated with vertical loading rate and leg stiffness. ...
... However, knee rotation of BR in this study was a little larger than SR (Table 1), which indicated that knee strength was not mainly influential factor. Besides above, we also found that BR and SR existed significant foot morphological differences, especially in the separated distance between large toe with other toes [10]. Biomechanical studies suggested that the separated large toe of BR and the other toes of SR had the specific prehensile function [29], which could not only share and reduce loading but offer push force for takeoff [20]. ...
... Habitually barefoot runner and shod runner existed biomechanical difference during barefoot jogging and running [10,20]. In sagittal ROM, they had similar lower-limb flexion-extension trajectory, but SR had the larger range than BR. ...
... In sagittal ROM, they had similar lower-limb flexion-extension trajectory, but SR had the larger range than BR. These results reflected that habitually shod runner under barefoot condition showed the highest joint flexion angle [10]. Some studies pointed that the lower-limb joint flexion angle was associated with vertical loading rate and leg stiffness. ...
... However, knee rotation of BR in this study was a little larger than SR (Table 1), which indicated that knee strength was not mainly influential factor. Besides above, we also found that BR and SR existed significant foot morphological differences, especially in the separated distance between large toe with other toes [10]. Biomechanical studies suggested that the separated large toe of BR and the other toes of SR had the specific prehensile function [29], which could not only share and reduce loading but offer push force for takeoff [20]. ...
Article
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The purpose of this study was to evaluate the biomechanical performances, running stability of habitually barefoot (BR) and shod runners (SR) during barefoot jogging and running. Ten healthy male subjects, 5 habitually shod runners and 5 habitually barefoot runners, from two different ethnics participated in this study. Subjects performed jogging (2m/s) and running (4m/s) along a 10-m runway. Three-dimensional lower-limb kinematics, ground reaction force, center of pressure (COP) and contact time (CT), were collected during testing. During jogging and running, all participants adopted rear-foot strike pattern, SR had larger VALR. SR showed significantly larger lower-limb range of motion (ROM) in sagittal plane, significantly larger hip abduction and opposite knee ROM in frontal plane, as well as significantly larger ankle internal rotation in horizontal plane. All participants’ CT showed decreased trend with running speed up; and SR was significantly longer than BR; BR and SR in COP showed different trajectories, especially forefoot and rearfoot areas. Habitually barefoot and shod runner from different ethnics still exist significant differences in lower-extremity ROM; and different foot morphological of participants is an important influential factor for these variations.
... Other symptoms, such as metatarsalgia, plantar callosities, hammer toe deformities are commonly observed in patients with severe HV [7,8]. Additional reasons for HV deformity include genetic predisposition, high-heeled shoes and other ill-fitted shoes, particularly footwear with constrictive toe-box [9,10,6,[11][12][13]. ...
... The present research about biomechanics of shod and unshod running has demonstrated that barefoot or 'minimalist shoes' may affect the development of foot morphology and alter foot biomechanics function performance compared to traditional footwear running [16,17,10,13]. The increase of both intrinsic and extrinsic foot muscular strength, proprioception, reduced foot impact forces and injury prevention associated with barefoot and 'minimalist shoes' have been previously reported [18,23]. ...
... * indicates significant difference with p < 0.05. Compared to the pre-intervention session, contact area in the post-intervention session increased in LM (for running) and LR (for walking) and may be explained by the fact that all participants in this study are habitually rearfoot runners [13]. However, several limitations should be considered. ...
... Data comparing foot structure in habitually-barefoot and habitually-shod populations have reported consistent differences in the spread/abduction of the great toe from the other toes [16][17][18][19]. Based on Newtonian physics, larger areas of support provide greater stability. ...
... Early research showed an active role of the toes, the great toe in particular, from midstance to toe off in running [24]. More recent data comparing habitually barefoot to habitually shod populations suggested that the abducted great toe position, characteristic of the barefoot group, reduced peak forefoot pressures during running by increasing the area of support [19]. Another comparative study from the same lab [25] found larger ankle eversion and internal rotation (which together comprise pronation) during the landing phase of jumping in habitually shod compared to habitually-barefoot participants, attributing differences to the abducted great toe position characteristic of the barefoot group. ...
... As this is the first study to explore the association between great toe valgus, pronation and frontal plane knee joint excursions during running, there are no studies with a similar approach for comparison. Nevertheless, the strong relationships observed broadly support findings from previous comparative cross-sectional studies of habitually barefoot and habitually shod participants that differed in forefoot structure with respect to the spread/abduction of the great toe [19,25]. Shu et al. [25] observed larger ankle eversion and internal rotation (which together comprise pronation) in habitually shod compared to habitually barefoot participants in the landing phase of jumping. ...
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The Foot and Ankle Online Journal 13 (1): 7 Injury rates in running range from 19.4-79.3%, with injuries at the knee comprising 42.1%. Pronation and altered frontal plane knee joint range of motion have been linked to such injuries. The influence of foot structure on pronation and knee kinematics has not been examined in running. This study examined associations between great toe valgus angle, peak pronation angle and frontal plane range of movement at the knee joint during overground running while barefoot. Great toe valgus angle while standing, and peak pronation angle and frontal plane range of motion of the dominant leg during stance while running barefoot on an indoor track were recorded in fifteen recreational runners. There was a large, negative association between great toe valgus angle and peak pronation angle (r =-0.52, p = 0.04), and a strong positive association between great toe valgus angle and frontal plane range of motion at the knee joint (r = 0.67, p = 0.006). The results suggest that great toe position plays an important role in foot stability and upstream knee-joint motion. The role of forefoot structure as a factor for knee-joint injury has received little attention and could be a fruitful line of enquiry in the exploration of factors underpinning running-related knee injuries.
... Other symptoms, such as metatarsalgia, plantar callosities, hammer toe deformities are commonly observed in patients with severe HV [7,8]. Additional reasons for HV deformity include genetic predisposition, high-heeled shoes and other ill-fitted shoes, particularly footwear with constrictive toe-box [9,10,6,[11][12][13]. ...
... The present research about biomechanics of shod and unshod running has demonstrated that barefoot or 'minimalist shoes' may affect the development of foot morphology and alter foot biomechanics function performance compared to traditional footwear running [16,17,10,13]. The increase of both intrinsic and extrinsic foot muscular strength, proprioception, reduced foot impact forces and injury prevention associated with barefoot and 'minimalist shoes' have been previously reported [18,23]. ...
... * indicates significant difference with p < 0.05. Compared to the pre-intervention session, contact area in the post-intervention session increased in LM (for running) and LR (for walking) and may be explained by the fact that all participants in this study are habitually rearfoot runners [13]. However, several limitations should be considered. ...
... Running has attracted extensive participation globally. As one of the most accessible physical activities to improve fitness and prevent obesity, cardiovascular diseases and other chronic health issues, participants tend to run long distances in order to further benefit from aerobic and endurance exercise [6], [14], [20], [27]. As reported, the number of finishers of full marathons increased by about 30% and number of participants of half marathons increased about by 300% over the past decade in the U.S. alone [23]. ...
... In China, participation reached the highest record of 2.8 million in long distance running events around the country throughout 2016 [3]. However, wide participation of repetitive prolonged running may lead to increased injury rates [14], particularly to the lower limb, such as knee, lower leg, foot and upper leg [27], [29]. ...
... Athletic footwear usage provides advantages to foot plantar surface protection, traction, dynamic motion control (stability), impact force attenuation [13] and comfort [28]. Particularly, shock-attenuating sport shoe properties (cushioning) are a key [4], as repetitive impact during running may lead to overuse injuries [14], [24], [26], [27]. ...
Article
Purpose: Prolonged running has been popularized globally in recent decades. This study was aimed to reveal information about foot morphology, shoe comfort and plantar loading among recreational heel-strike runners. Methods: Twenty-six runners participated in foot morphology, perceived scores and peak pressure tests after 10- and 20-km track running. The foot morphology was measured using a 3D foot scanner, perceived scores were recorded using a visual analogue scale and plantar pressure was measured via insole plantar pressure measurement system. The statistical significance level was set at 0.05. Results: The heel midsole materials properties were measured before and after 20 km. Significant changes were observed in ball width and girth, arch height and foot volume. The perceived scores showed significance in overall, forefoot and heel comfort, arch support and forefoot width. Peak pressure to the heel, medial mid-foot and metatarsal greatly increased. The first metatarsal showed consecutive increase from static to 10 km, and 20 km, while big-toe showed a decrease. Conclusions: The morphology variations and forefoot loading concentration may lead to discomfort and possibly imply dermatological problems and metatarsal bone stress, particularly on the first metatarsal. Combining changes of heel midsole property, knowledge of foot shape, shoe perception and plantar pressure is of great value for recreational long-distance running shoes design and materials selection.
... Different foot arch types (flat, high and normal) have been reported to present both static and dynamic biomechanical functions for asymptomatic or pathological feet [6], [16]. Important toe functions, both prehensile and ambulatory, have evolved naturally [9], and are believed to increase the load bearing area in the pushoff phase of locomotion [13], [14]. However, foot deformities, particularly to the forefoot [14] and toes, like hallux valgus [4], present medially focused plantar loading to the metatarsal region. ...
... The kinematics test utilized an eight-camera Vicon 3D motion analysis system (Oxford Metrics Ltd., Oxford, UK) and Nexus version 1.8.5 software to collect and process lower limb kinematic data at a frequency of 200 Hz. The Plug-In-Gait model [5], [13], using sixteen reflective markers, was used to capture the lower limb kinematic data. Reflective markers (12 mm in diameter) were used to define the joint centre and motion axis, including left anterior-superior iliac spine (LASI), right anterior-superior iliac spine (RASI), left posterior-superior iliac spine (LPSI), right posteriorsuperior iliac spine (RPSI), left thigh (LTHI), right thigh (RTHI), left knee (LKNE), right knee (RKNE), left tibia (LTIB), right tibia (RTIB), left ankle (LANK), right ankle (RANK), left heel (LHEE), right heel (RHEE), left toe (LTOE) and right toe (RTOE). ...
... After five minutes' warm-up and familiarization, participants were required to run on the track with self-selected speed to present natural running characteristics and complete collection of six successful trials of kinematic and plantar pressure data. Stance contact time and running speed were measured to evaluate gait patterns similar to previous studies [5], [6], [8], [13], [16]. Kinematic data collection included mean joint angle (±SD), peak angle, joint range of motion of hip, knee and ankle during stance [5], [13]. ...
Article
Purpose: Functional footwear with different unstable profiles has been widely used to mimic barefoot condition and offload plantar loading for pathological or injury prevention. However, little research investigates the effect of unstable structure on particular foot functions. In this study, a prototype of unstable shoe design with unstable element of different stiffness placed at the hallux (a regionalized rocker) was used. The primary objective was to analyse the biomechanical performance of running with hallux unstable shoes, aiming to potentially stimulate and increase the toe gripping function. Methods: The lower limb kinematics and plantar pressure distribution were measured to comparatively analyse the soft (SS) and hard (SH) unstable shoes with flat control shoes (CS). Results: The SS showed increased big toe and reduced forefoot plantar pressure. The SS led to similar lower limb kinematics to baseline CS except for reduced hip abduction, increased rotation range of motion (ROM), increased peak ankle plantar flexion and ROM. The SH presented significantly altered lower limb kinematics across hip, knee and ankle, and laterally distributed plantar pressure. Conclusions: Unstable shoes with soft material led to reduced medial metatarsal loading by increasing the support area and modified joint kinematics minimally. Unstable shoes with stiffer material presented compensatory kinematic movements across all joints and laterally shifted plantar loading distribution. These findings may provide implications on toe grip function training for foot pressure off-loading.
... There are few studies that analyse the effect of plantar pressure combining both factors: minimalist shoes and prolonged running [36,37]. In addition, most research with MS does not consider other important factors such as the type and/or pattern of foot strike (forefoot, rearfoot, midfoot), or the runners' previous experience with this type of shoe [8,9,[29][30][31][32][36][37][38][39]. Therefore, the aim of this study was to analyse the changes produced using MS on plantar pressure during a prolonged running, as well as its interaction with the time and foot strike pattern. ...
... The aim of this study was to analyse the changes produced using MS on plantar pressure during a prolonged running, as well as their interaction with the time and foot strike patterns. In this sense, there are few studies that analyse the effect of MS on plantar pressure, and most of these studies do not consider the foot strike pattern (FF, MF, RF), not knowing whether the differences found are associated with the footwear type, foot strike pattern during running or the interaction of both [8,9,[29][30][31][32]38,45]. ...
... In terms of contact area and contact time, the shoe*foot strike pattern interaction reveals that in MS, forefoot runners show less contact time and contact area compared to midfoot/rearfoot runners (Figure 1). Thus, in relation to the contact area, and considering exclusively the footwear type, the results are in line with Mei et al. [38], who observed a decrease in the contact area in the forefoot and midfoot area when analysing barefoot running vs. CS. However, if the foot strike pattern is considered, our results are contrary to those obtained by these authors, as they observed a decrease in this in rearfoot runners in the barefoot condition, probably due to the absence of any type of sport shoes that suppose a small protection. ...
Article
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The use of minimalist shoes (MS) in running involves changes in running mechanics compared to conventional shoes (CS), but there is still little research analysing the effects of this footwear on plantar pressure, which could help to understand some risk injury factors. Moreover, there are no studies examining the effects of a prolonged running and foot strike patterns on baropodometric variables in MS. Therefore, the aim of this study was to analyse the changes produced using MS on plantar pressure during a prolonged running, as well as its interaction with the time and foot strike pattern. Twenty-one experienced minimalist runners (age 38 ± 10 years, MS running experience 2 ± 1 years) ran with MS and CS for 30 min at 80% of their maximal aerobic speed, and mean pressure, peak pressure, contact time, centre of pressure velocity, relative force and contact area were analysed using a pressure platform. Foot strike pattern and time were also considered as factors. The multivariable linear regression mixed models showed that the use of MS induced, at the end of a prolonged running, higher peak pressure (p = 0.008), lower contact time (p = 0.004) and lower contact area (p < 0.001) than using CS. Also, runners with forefoot strike pattern using MS, compared to midfoot and rearfoot patterns, showed higher mean and peak pressure (p < 0.001) and lower contact time and area (p < 0.05). These results should be considered when planning training for runners using MS, as higher peak pressure values when using this type of footwear could be a risk factor for the development of some foot injuries.
... A total of 15 studies met the inclusion criteria and were included in the qualitative analysis. Of these, six investigated biomechanics (12,20,21,(37)(38)(39), five investigated foot morphology (5,7,12,34,52) and three examined the foot arch (14,48,53). One study assessed the injury incidence (3), and another single study reported on diseases (4). ...
... Study characteristics of all included studies are summarized in Table 1 (3)(4)(5)7,12,14,20,21,34,(37)(38)(39)48,52,53). Most studies on HB subjects were performed in Asia and Africa (Fig. 2). ...
... Most studies on HB subjects were performed in Asia and Africa (Fig. 2). Seven studies reported on recreational and competitive runners (3,4,20,(37)(38)(39)52), whereas eight studies did not specify the sporting activities of the participants. These studies reported on healthy children (5,14,48), adults (5,7,12,21,34), and barefoot fishermen (53). ...
Article
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Introduction: Barefoot locomotion is widely believed to be beneficial for motor development and biomechanics but are implied to be responsible for foot pathologies and running-related injuries. While most of available studies focused on acute effects of barefoot running and walking little is known regarding the effects of long-term barefoot vs. shod locomotion. The purpose of this study was to systematically review the literature to evaluate current evidence of habitual barefoot (HB) vs. habitual shod locomotion on foot anthropometrics, biomechanics, motor performance and pathologies. Methods: Four electronic databases were searched using terms related to habitually barefoot locomotion. Relevant studies were identified based on title, abstract and full text and a forward (citation tracking) and backward (references) search was performed. Risk of bias was assessed, data pooling and meta-analysis (random effects model) performed and finally levels of evidence determined. Results: Fifteen studies with 8399 participants were included. Limited evidence was found for a reduced ankle dorsiflexion at footstrike (pooled effect size -3.47 (95% CI -5.18 to -1.76)) and a lower pedobarographically measured hallux angle (-1.16 (95% CI -1.64 to -0.68)). HB populations had wider (0.55 (95% CI 0.06 to 1.05) but no shorter (-0.22 (95% CI -0.51 to 0.08)) feet compared to habitual shod populations. No differences in relative injury rates were found, with limited evidence for a different body part distribution of musculoskeletal injuries and more foot pathologies and less foot deformities and defects in HB runners. Conclusions: Only limited or very limited evidence is found for long-term effects of HB locomotion regarding biomechanics or health-related outcomes. Moreover, no evidence exists on any beneficial effects for motor performance. Future research should include prospective study designs.
... foot during walking [95], and reduced peak pressure and pressure-time integral under the forefoot when running [100]. Given that pressure is force divided by area of contact, these observations support the natural selection of a wide forefoot to serve a support function. ...
... The notable spread and abducted position of this toe from the others characterises habitually-barefoot populations [95,96,99]. Increased thickness and an abducted position of the great toe in humans are evolved-functional adaptations providing directional stability in bipedal locomotion [100]. These adaptations are important considering that direction of ground-reaction forces (and the resulting joint moments created) contribute to injury [101][102][103]. ...
... 4 The average peak pressure under forefoot and toes regions during take-off and landing phase. "Red square" indicated a significant difference between HSM and HBM second toe separation compared with HSM (Shu et al. 2015;Mei et al. 2015). This study verified differences in ankle kinematics and plantar loading between the two populations in vertical jump. ...
... This suggested different functions of the hallux in motion control between HBM and HSM. Mei et al. (2015) also reported larger loading under the hallux among HBM during running, which may reduce impact force to forefoot area. ...
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Purpose This study examined differences in ankle motion and plantar pressure between habitually barefoot male (HBM) and habitually shod male (HSM) during vertical jump. Methods Eighteen habitually barefoot males and twenty habitually shod males volunteered to join the test. Distance between hallux and second toe was measured with Easy-Foot-Scan. Plantar pressure and ankle kinematics were measured with EMED force platform and Vicon motion analysis system respectively. T test was taken to analyse the significant differences using Stata 12.0 software. Results The distance between hallux and other toes in HBM was greater than it in HSM. HBM showed larger plantar loading under hallux and medial forefoot, while HSM showed lager plantar loading under medial and central forefoot. HBM had smaller ankle plantarflexion, eversion and external rotation than HSM. Conclusion Findings of this study provide basic information for further studies on different hallux/toe function in motion control between habitually shod and barefoot populations.
... The most meaningful differences seen in the kinematics between the three running conditions were in the ankle angles. Other studies have reported a marked difference in ankle angle at touchdown when running barefoot compared to running shod on a treadmill (3,11,12,31) and over ground (14,22,23,33,34). The current study found that at touchdown, the subjects had a plantarflexed ankle when barefoot and a dorsiflexed ankle when shod. ...
... The contact time did not differ between conditions, but the barefoot condition did have a smaller contact time than the shod condition which has been a common finding by researchers comparing barefoot to shod running (5,8,23). Other researchers have also reported no difference in contact time when running a comparable speed (11,32). ...
Article
Barefoot running is considered to decrease injury risk, but is not always practical, particularly while running on a fitness center treadmill. The purpose of this study was to compare the kinematics of shod, barefoot, and simulated barefoot running. Twelve subjects (age = 21.1 ± 1.2 years) who regularly run on a treadmill for fitness participated in the study. After a warm up, each runner ran on a Biodex RTM 400 treadmill set at 7.4 mph (approximately 3.3 m/s) in their own shoes, barefoot, and while running “like they were barefoot” in their own shoes. Sixteen reflective markers were affixed to each subject to use PlugInGait (Vicon) to determine three-dimensional body landmark coordinates and to compute lower extremity joint angles. Values at touchdown and during stance were averaged over ten strides for analysis. Repeated measures ANOVA was implemented to determine differences based on running condition (p < 0.05) and post hoc testing was performed with an adjustment for multiple comparisons (p<0.05/3). At touchdown, ankle angle values significantly differed based on condition (6.2 ± 5.9° vs. −4.0 ± 12.0° vs, −0.2 ± 13.3°; p = 0.004 for shod, barefoot and simulated barefoot running, respectively) indicating that when simulating barefoot running the subjects altered their foot strike pattern. Stride frequency differed between shod and barefoot running (1.415±0.068 Hz vs. 1.457±0.065 Hz; p = 0.001) but the simulated barefoot condition did not differ from the shod condition. The runners were able to simulate an important element of barefoot running, but they did not completely mimic their barefoot running pattern.
... Barefoot eversion is up to 8.6 degrees, reaching 16 degrees under shod conditions (Reinschmidt et al., 1997). Unlike our findings and those of other authors (Clarke et al., 1983;Gheluwe et al., 1995;Mei et al., 2015;Nigg and Morlok, 1987;Reinschmidt et al., 1997;Stacoff et al., 1990) reported a higher rearfoot eversion angle in barefoot runners when compared to their shod counterparts. However, RFA differences of up to 20 degrees between barefoot and shod runners are more frequently described in the literature (Stacoff et al., 1990) than no differences or the opposite scenario, as reported by Mei et al., 2015. ...
... Unlike our findings and those of other authors (Clarke et al., 1983;Gheluwe et al., 1995;Mei et al., 2015;Nigg and Morlok, 1987;Reinschmidt et al., 1997;Stacoff et al., 1990) reported a higher rearfoot eversion angle in barefoot runners when compared to their shod counterparts. However, RFA differences of up to 20 degrees between barefoot and shod runners are more frequently described in the literature (Stacoff et al., 1990) than no differences or the opposite scenario, as reported by Mei et al., 2015. Thus, our findings confirm the initial hypothesis that running shoes increase the eversion angle in relation to running barefoot. ...
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The rearfoot angle (RFA) is a biomechanical variable widely used to determine the rearfoot motion (RM). Shoe manufacturers began to develop running shoes with RM control that would supposedly alter foot-ground interaction mechanics and neutralize excessive pronation or supination; moreover, some studies have not shown differences in rearfoot motion in shod condition compared to barefoot. This study intended to answer three questions: Do the shoes runners wear correspond to their respective barefoot RM? Does the eversion angle change during shod running, regardless the shoes worn? Can footwear designed for a specific RM (supination, pronation, neutral) correct or neutralize the eversion angle of runners? One hundred and eleven runners (38.6 ± 9.7years; 74.9 ± 12.0kg; 1.74 ± 0.08 m), who ran an average of 32 ± 17km/week, were included in this cross-sectional study. They had their RFA measured by a motion capture system when running barefoot and wearing their habitual running shoes (shod condition). Chi-squared test was used to assess associations between barefoot and shod condition and RFA was compared between conditions using Wilcoxon tests (p = 0.05). There was no association between the type of running shoe and barefoot RM (p > 0.05). There was an association between RFA when barefoot and when shod (p < 0.05). Among all participants classified as neutral, 61% continued to exhibit a normal/neutral RFA when wearing their habitual shoes. Among the overpronators, 100% showed a change in the RM to either normal or supinator. Among the participants classified as supinators, 62% exhibited normal pronation when shod even without using the appropriate footwear, claimed by the manufacturer. Only 44.1% of the sample chose the correct running shoe for their barefoot RM. The majority of runners did not choose their shoes designed for their natural type of RM. The rearfoot eversion angle changed an average 4 degrees when running shod and the RM barefoot altered quite a lot when using a running shoe. The running shoes did not correct the pronation detected barefoot, as claimed by the manufacturers.
... It is not surprising therefore, that comparisons of habitually-unshod with habitually-shod populations consistently show wider (particularly at the front) feet in unshod populations, in agreement with that predicted by fundamental principles [6][7][8][9][10]. Studies on habitually-barefoot populations also demonstrate the benefits of a wide base of support in the form of more uniform distribution of pressure through the entire plantar surface during walking [9], and reduced peak pressure and pressure-time integral under the forefoot in running [11]. ...
... A relationship between Morton's toe and peak pressure under the first metatarsal head in walking has also been demonstrated, providing support for the assertion that static-foot structure is an important determinant of foot function, specifically, the ability to direct body weight in the sagittal plane in locomotion [20]. More recently, Mei et al [11] demonstrated the importance of an abducted-hallux position in habitually-barefoot participants while running, showing the hallux to share and therefore reduce forefoot loading, possibly due to a wider surface area of support . ...
Article
The Foot and Ankle Online Journal 9 (2): 5 There has been and continues to be much debate about the merits and detriments of barefoot and minimal-shoe running. Research on causes of running-related injury is also characterised by equivocal findings. A factor common to both issues is the structure and function of the foot. Comparatively, this has received little attention. This perspective piece argues that foot function and in particular, how foot structure determines function, has largely been overlooked, despite basic principles of physics dictating both the link between structure and function and the importance of function for stability in locomotion. We recommend that foot shape and function be considered in the interpretation of existing findings and be incorporated into future investigations interested in running mechanics, injury mechanisms and the effects of footwear on both. s stated by evolutionary biologist EO Wilson, " everything in biology is subject to the laws of physics and chemistry and has arisen through evolution by natural selection " [1]. Applying this logic to the study of human locomotion, and in particular the structure and role of the foot, can bring clarity to the interpretation of many past and recent studies on barefoot-versus-shod-and minimal-shoe locomotion, and the associated benefits and risks. Using laws and undisputed theories as filters through which to interpret study outcomes can provide a context to equivocal findings and also suggest fruitful lines of future inquiry. The 'purpose' of the foot Assigning a purpose to a biological structure is often criticised as teleological. However, as Nobel Laureate Albert Szent-Gyorgyi [2] wrote " teleology resembles an attractive lady of doubtful repute whose company we cherish but in whose company we do not like to be seen ". Purpose provides the context without which many observations in nature make no sense. A teleological view is therefore adopted in this piece. In an upright biped, the purpose of the foot is to support and control the direction of the body weight as it falls forwards during the stance phase of locomotion [3-5]. With this and fundamental physics in mind, a reverse-engineering approach suggests a larger base of support, that is widest at the front, would serve both purposes.
... Hierbij wordt het voetgedeelte dat als eerste de grond raakt uitgedrukt als een percentage van de voetlengte (0-33 % is hiel-Figuur 1 Voetlandingspatroon bij renners die blootsvoets (blauw) en geschoeid (rood) lopen. HL hiellanding, ML middenvoetlanding, VL voorvoetlanding landing, 34-66 % is middenvoetlanding en 67-100 % is voorvoetlanding) [8][9][10]. De teenlanding speelt vooral een rol bij de sprint. ...
... In de onderzoeksliteratuur wordt dit verschil in grondreactiekrachten bij de hiel-of voorvoetlanding, zoals gegeven in fig. 2, steeds gevonden [1,2,9,10,[21][22][23][24][25][26]. ...
Article
De laatste acht jaar is er in de wetenschap en daarbuiten een interessante (en soms heftige) discussie ontstaan over de vraag wat beter is: geschoeid hardlopen of blootsvoets (barefoot running). Uit de literatuur blijkt dat het geen verschil maakt voor het aantal blessures, maar dat juist het type voetlanding (op de hiel of op de voorvoet) veel meer effect heeft op de krachten tijdens het neerkomen dan het al dan niet dragen van schoenen. Ook blijkt dat bij het overgaan van geschoeid naar blootsvoets hardlopen, of naar hardlopen op minimalistisch schoeisel, meer dan de helft van de renners een hiellanding blijft gebruiken.
... Another information was that the children's feet may be different to adult ones because of the plastic feature of the foot-ankle complex, especially in SPD children with the motor disorder of this study. The foot-ankle complex was often characterized by altered foot shape and function [43][44][45][46]. Because of the plasticity in this complex, the loading in the MF region increased greatly during running and turning, suggesting less stability or reduced control of the longitudinal arch [43] and reduced force in the distal segment of toes [47,48]. ...
... During turning activity (or known as cutting maneuvers), participants may decelerate in the original direction and redirect to the intended direction during turning, requiring acceleration [56]. Accordingly, the direction changing mechanism would account for the increased force loading under the M1 and M2 regions, and it is facilitated with active toe gripping motion in healthy controls (but not observed in SPD children) [46,48,57]. ...
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Sensory processing disorder (SPD) could influence the neuromuscular response and adjustment to external sensory discrimination and lead to disruptions in daily locomotion. The objective of the current study was to compare plantar loadings and foot balance during walking, running and turning activities in SPD children in order to reveal the behavioral strategy of movement and balance control. Six SPD children and six age-match healthy controls participated in the test using a FootScan plantar pressure plate. The time-varying parameters of forces, center of pressure and foot balance index were analyzed using an open-source one-dimensional Statistical Parametric Mapping (SPM1d) package. No difference was found in foot balance and plantar loadings during walking, while limited supination–pronation motion was observed in the SPD children during running and turning. The plantar forces were mainly located in the midfoot region while less toe activity was found as well. Findings should be noted that SPD children had limited supination–pronation movement for shock attenuation in the foot complex and reduced ankle pronation to assist push-off and toe gripping movements. Understanding the behavior of plantar loading strategy and balance control during walking, running and turning activities may provide clinical implications for the rehabilitation and training of daily tasks.
... Typically, the vertical GRF consists of a first peak as heel landing and a second peak during pushing-off (Wannop et al., 2012;Mei et al., 2015), and the ant-post GRF includes braking peak and propulsion peak (Wannop et al., 2012). In contrast, the med-lat GRF showed little consistency and high variations in the pattern and shape, which might be due to the different foot placements, footwear condition, and environmental surface while running (McClay and Cavanagh, 1994;Samaan et al., 2014;Seeley et al., 2020). ...
... As documented in the literature, factors such as speed, sex, fatigue, and footwear altered the response in the running GRFs (Logan et al., 2010;Mei et al., 2015;Bazuelo-Ruiz et al., 2018). Female runners presented a reduced loading rate (LR) and first peak, whereas males had higher peak propulsive forces under fatigue conditions (Bazuelo-Ruiz et al., 2018). ...
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Ground reaction force (GRF) is a key metrics in biomechanical research, including parameters of loading rate (LR), 1st impact peak, 2nd impact peak, and transient between 1st and 2nd impact peaks in heel strike runners. The GRFs vary over time during stance. This study was aimed to investigate the variances of GRFs in rearfoot striking runners across incremental speeds. Thirty female and male runners joint the running tests on the instrumented treadmill with speeds of 2.7m/s, 3.0m/s, 3.3m/s and 3.7m/s. The discrete parameters of vertical average loading rate (VALR) in the current study are consistent with findings from the literature. Principal component analysis was modelled to investigate the main variances (95%) in the GRFs over stance. The females varied in the magnitude of braking and propulsive forces (PC1, 84.93%), while the male runners varied in the timing of propulsion (PC1, 53.38%). The female runners dominantly varied in the transient between the 1st and 2nd peaks of vertical GRF (PC1, 36.52%) and LR (PC2, 33.76%), while the males variated in the LR and 2nd peak of vertical GRF (PC1, 78.69%). Knowledge reported in the current study suggested the difference of the magnitude and patterns of GRF between male and female runners across different speeds. Knowledge reported in the current study may have implications for the prevention of gender-specific running-related injuries and could be integrated with wearable signals for the in-field prediction and estimation of impact loadings and ground reaction forces.
... Three-dimensional kinematic data was captured using an eight-camera Vicon motion analysis system (Oxford Metrics Ltd., Oxford, UK) with a frequency of 200 Hz. This measuring system has been used previously in kinematic analysis of sports such as running and walking (Mei et al., 2015;Shu et al., 2016;Fu et al., 2016b). All participant were asked to wear tight-fitting pants, and sixteen reflective markers (diameter: 14 mm) were adhered on the lower limbs. ...
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Background The table tennis serve involves complex spatial movements combined with biomechanial characteristics. Although the differences in lower-limb biomechanial characteristics to a great extent influence the translational and spinning velocity of the ball when using the different styles of table tennis serve, few researchers have studied their mechanics. Therefore, the aim of this study was to investigate the differences in lower-limb activity between the squat and standing serves during a table tennis short serve. Methods Ten advanced female table tennis participants performed a squat serve and standing serve in random order. A Vicon motion analysis system and a Novel Pedar insole plantar pressure measurement system were used to record kinematics and kinetics data, respectively. Results Key findings from the study were that the squat serve not only showed significantly larger hip and knee flexion, as well as ankle dorsiflexion, it also showed significantly larger hip adduction and external knee rotation, with larger changing angular rate of the lower limb joints in the sagittal and the transverse planes when the two serving styles were compared. In addition, the force-time integral (FTI) was higher in the rear foot area for the standing serve. Discussion The results demonstrated that the squat serve needs higher lower limb drive during a table tennis short serve compared with a standing serve. These biomechanical considerations may be beneficial for table tennis athletes and coaches as a method of optimizing performance characteristics during both competition and training.
... The following foot intersegment kinematic variables were selected for analysis in this study: hindfoot relative to tibia (HF/TB), forefoot relative to hindfoot (FF/HF), and hallux relative to forefoot (HX/FF, sagittal plane only). For foot kinematic variables, angle values at HC/HO and TO/TC, as well as peak angles and ROM values in the stance phase were derived (Mei, Fernandez, Fu, Feng, & Gu, 2015). The foot was divided into seven anatomical regions, including big toe (BT), other toes (OT), medial forefoot (MFF), central forefoot (CFF), lateral forefoot (LFF), midfoot (MF), and heel (H). ...
Article
Backward walking (BW) has been extensively used in athletic training and orthopedic rehabilitation as it may have value for enhancing balance. This study identified the differences in foot intersegment kinematics (forward walking (FW) vs. time-reversed BW) and plantar pressure parameters of 16 healthy habitually shod individuals walking FW and BW using flexible shoes (SH) and under barefoot conditions (BF). BW was found to have shorter stride length (SL) and higher stride frequency (SF) under BF conditions compared with SH, which indicates a better BW gait stability under BF conditions. Decreased HX/FF dorsiflexion at HO in BW induces less plantar aponeurosis tension which may inhibit the windlass mechanism compared to FW walking. Increased forefoot relative to hindfoot (FF/HF) pronation and sequentially hindfoot relative to tibia (HF/TB) eversion combined with medially distributed plantar pressure and a higher plantar contact area in the medial side in BW-BF maybe beneficial in maintaining balance. These results indicate that BW training may be more reliable under BF conditions compared to the SH conditions based on greater sensory information feedback from the plantar area resulting in better biomechanical behavior.
... Increased horizontal GRF make greater higher loads on the lateral ankle ligaments during 45° cut, leading to more potential risk to lateral ankle sprains (Jenkyn and Nicol, 2001). Higher VALR may increase the impact force to lower limbs and may lead to potential risk of tibia stress fracture and plantar fasciitis (Mei et al., 2015). Peak pressure and force-time integral in the heel (H) region of FG were also significantly higher than TF (Figure 5), which would also increase the potential risk factors of tibia stress fractures and plantar fasciitis (Lieberman et al., 2010). ...
Article
The purpose of this study was to testing for difference in performance and injury risks between three different outsole configuration soccer shoes on natural turf. A total of 14 experienced soccer players participated in the tests. Participants were asked to complete tasks of straightahead running and 45° left sidestep cutting respectively at the speed of 5.0±0.2 m/s on natural turf. They selected soccer shoes with firm ground design (FG), artificial ground design (AG) and turf cleats (TF) randomly. During 45° cut, FG showed significantly smaller peak knee flexion and greater abduction angles than TF. FG showed significant greater peak horizontal ground reaction force (GRF) and average required traction ratio compared with AG and TF. FG may offer a performance benefit on artificial turf compared to AG and TF on natural turf. However, increased knee valgus angle and decreased knee flexion angle of FG may increase knee loading and risk of anterior cruciate ligament (ACL) injury. Higher vertical average loading rate and excessive plantar pressure of FG may also resulted in calluses observed in plantar skin, forefoot pain or even metatarsal stress fracture. In summary, FG would enhance athletic performance on natural turf, but also may undertake higher risks of non-contact injuries compared with AG and TF.
... some corresponding changes among pregnant women in previous studies, 3 16 even for those population of different ethnicities with different daily life activities or custom show unique foot morphological feature. 17 Considering the foot morphology and plantar loading variations, diabetes mellitus was a common disease with deformed foot morphology and regionalized high plantar loading concentration to medial forefoot and great toe, which would be potential risks of plantar ulceration. 18 And some exploratory research about footwear structure and insole materials (different stiffness) for plantar loading alleviation in specific region were conducted for the purpose of prevent possible foot pain or even ulceration. ...
Article
Pregnancy has been a critical stage for most females. Daily locomotion during this specific period was altered owing to the weight gain from fetus. The objective of this study was to illustrate the plantar loading distribution characteristics of pregnant women in different trimester through comparative analysis with non-pregnant women. Thirty-six pregnant women and thirty-six non-pregnant women were recruited to participate walking test with self-preferred speed (1.5∼1.8 m/s). NovelPedar insole measurement system was utilized to record data of plantar loading. As the results shows, the peak pressure to the midfoot showed an increasing tendency as the pregnant trimester progressing in both feet. Due to pregnant trimester progressing, the impulse to the lateral foot side was obviously increasing. Reveal the adjusted gait plantar loading characteristics of pregnant women in different trimesters could help to guarantee the safety of expectant mothers and fetuses.
... Furthermore, little evidence on the predominant influences of shoe conditions or foot strike patterns on foot loading during running is available. Plantar pressure measurement has been widely used to examine the actual loading applied to the feet (Mei et al., 2015;Queen et al., 2007). Knowledge on how plantar pressure combined with impact forces occur in response to different foot strike patterns and shoe conditions would be useful to better understand variations in foot and lower extremity loading and runningrelated injuries from both movement control and shoe roles. ...
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This study aimed to explore the effects of strike patterns and shoe conditions on foot loading during running. Twelve male runners were required to run under shoe (SR) and barefoot conditions (BR) with forefoot (FFS) and rearfoot strike patterns (RFS). Kistler force plates and the Medilogic insole plantar pressure system were used to collect kinetic data. SR with RFS significantly reduced the maximum loading rate, whereas SR with FFS significantly increased the maximum push-off force compared to BR. Plantar pressure variables were more influenced by the strike patterns (15 out of 18 variables) than shoe conditions (7 out of 18 variables). The peak pressure of midfoot and heel regions was significantly increased in RFS, but appeared in a later time compared to FFS. The influence of strike patterns on running, particularly on plantar pressure characteristics, was more significant than that of shoe conditions. Heel-toe running caused a significant impact force on the heel, whereas wearing cushioned shoes significantly reduced the maximum loading rate. FFS running can prevent the impact caused by RFS. However, peak plantar pressure was centered at the forefoot for a long period, thereby inducing a potential risk of injury in the metatarsus/phalanx.
... Increased horizontal GRF of AG may make higher loads on the lateral ankle ligaments during 45° cutting movement, which may leading to more potential risk to lateral ankle sprains [37]. Higher VALR of AG may increase the impact force to lower limbs and may lead to potential risk of tibia stress fracture and plantar fasciitis [38]. Peak plantar pressure and force-time integral in the heel (H) region of AG were also showed significantly higher than TF and IN (Fig. 4), which would also increase the potential risk factors of tibia stress fractures and plantar fasciitis [39]. ...
Article
The purpose of this study was to testing for difference in performance and injury risks between three different outsole configuration soccer boots on artificial turf. Fourteen experienced soccer players performed 45° cut test. They selected soccer boots with artificial ground design (AG), turf cleats boots (TF) and indoor boots (IN) randomly. A Vicon three dimension motion analysis system was used to capture kinematic data and Kistler force platform was used to record the ground reaction force. Novel Pedar-X insole plantar pressure measurement system was utilized to collect the plantar pressure synchronized. During 45° cut, artificial ground design (AG) showed significantly smaller peak knee flexion (p<0.001) and greater abduction angles (p<0.001) than indoor boots (IN). AG showed significantly greater vertical average loading rate (VALR) compared with TF (p=0.005) and IN (p=0.003). The results of plantar pressure found that AG showed the highest peak pressure and force-time integral in the heel (H) and medial forefoot (MFF). Artificial ground design (AG) and turf cleats (TF) may offer a performance benefit on artificial turf compared to IN. In summary, AG may enhance athletic performance on artificial turf, but also may undertake higher risks of non-contact injuries compared with TF and IN.
... To our knowledge, this is the first study to compare FSP between HB and HS children and therefore these findings are difficult to compare. There are a couple of studies investigating FSP of HB adults, comparing them to HS counterparts [24,25,27] and a few reports on adolescents [24,25]. Lieberman et al. [25] reported a rate of RFS of 12 % in HB and 62 % in HS Kenyan adolescents running barefoot at a selfselected speed. ...
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Effects of early and permanent footwear use are not well understood. The aim of this study was to investigate the effects of habituation to footwear on foot strike patterns of children and adolescents. Healthy habitually barefoot and shod participants (aged 6–18 years) from South Africa (n = 288) and Germany (n = 390) performed multiple 20-m jogging and running trials with and without shoes. Each foot strike was captured using a high-speed camera to determine a rearfoot or non-rearfoot strike. The probability of a rearfoot strike in both cohorts and each age was analyzed by using a mixed-effects logistic regression adjusted for possible confounders. Habitually barefoot children showed a higher probability of using rearfoot strikes than habitually shod children (p < 0.001). The probability was age-dependent and decreased in habitually barefoot children with age (OR(barefoot-jogging) = 0.82, 95 % CI, 0.71 to 0.96, p = 0.014; OR(barefoot-running = 0.58), 95 % CI, 0.50 to 0.67, p < 0.001 and OR(shod-running) = 0.68, 95 % CI, 0.59 to 0.79, p < 0.001). In habitually shod children, the probability increased significantly for shod jogging (OR = 1.19, 95 % CI, 1.05 to 1.35, p = 0.006). To conclude, foot strike patterns of children are inuenced by habituation to footwear. Younger habitually barefoot children show higher rates of rearfoot strikes for shod and barefoot running, and it converges in later adolescence.
... Humans will display different postures during the movement, and the change in joint stress will be accompanied (Mei et al., 2015;Li and Gu, 2018;Gu and Sun, 2019). In a study investigating running injuries, James et al. found that valgus at the ankle joint leads to internal rotation of the tibia, which can lead to pain in the knee joint (James et al., 1978). ...
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Background Barbell squats are commonly used in daily training and rehabilitation. Injuries are not common when the posture is standard, but the wrong posture can lead to injuries. Rearfoot valgus is a common foot abnormality that may increase the risk of injury during sports. The purpose of this study was to compare the biomechanics of lower limbs in normal foot and valgus patients during barbell squat. Methods In this study, 10 participants with normal foot shape and 10 participants with rearfoot valgus were enrolled. The joint angle, joint moment, and range of motion of hip, knee, and ankle joints were collected under 0, 30, and 70% one-repetition maximum (RM) load, where discrete data are statistically analyzed using the independent sample t -test, and continuous data are statistically analyzed using one-dimensional parameter statistical mapping. Results In barbell squats, the range of motion and the joint moment of the hip, knee, and ankle in the rearfoot valgus participants were significantly larger than those in normal foot participants ( p < 0.05). The participants with rearfoot valgus had a more significant knee valgus angle when squatting to the deepest ( p < 0.05). In addition, with the increase in load, the participants with rearfoot valgus showed greater standardized medial knee contact force ( p < 0.05). In the process of barbell squats, the participants with rearfoot valgus showed no significant difference in the foot valgus angle when compared with the normal foot shape ( p > 0.05). Conclusions The valgus population showed a greater range of joint motion when performing barbell squats and showed genu valgus and greater medial knee contact force, which may increase the risk of musculoskeletal and soft tissue damage such as meniscus wear. In addition, there was no significant difference in the rearfoot valgus angle between people with rearfoot valgus and people with normal foot shape during squatting, so barbell squatting may correct valgus to a certain extent.
... 13 It was shown that adults habituated to barefoot locomotion have lower rates of rearfoot strikes 7,17,18 and corresponding reduced ankle and foot strike angles, as well as altered ground-reaction forces. 7,17,18,22 The findings for reduced rates of rearfoot strikes were not confirmed for nonathletic and pediatric populations, in which females and younger children habituated to barefoot locomotion predominantly used a rearfoot strike. 9,10,12,26 The limitations of these findings on long-term adaptations of barefoot locomotion are that they were derived from crosssectional studies. ...
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Background: Previous studies have shown that changing acutely from shod to barefoot running induces several changes to running biomechanics, such as altered ankle kinematics, reduced ground-reaction forces, and reduced loading rates. However, uncertainty exists whether these effects still exist after a short period of barefoot running habituation. Purpose/hypothesis: The purpose was to investigate the effects of a habituation to barefoot versus shod running on running biomechanics. It was hypothesized that a habituation to barefoot running would induce different adaptations of running kinetics and kinematics as compared with a habituation to cushioned footwear running or no habituation. Study design: Controlled laboratory study. Methods: Young, physically active adults without experience in barefoot running were randomly allocated to a barefoot habituation group, a cushioned footwear group, or a passive control group. The 8-week intervention in the barefoot and footwear groups consisted of 15 minutes of treadmill running at 70% of VO2 max (maximal oxygen consumption) velocity per weekly session in the allocated footwear. Before and after the intervention period, a 3-dimensional biomechanical analysis for barefoot and shod running was conducted on an instrumented treadmill. The passive control group did not receive any intervention but was also tested prior to and after 8 weeks. Pre- to posttest changes in kinematics, kinetics, and spatiotemporal parameters were then analyzed with a mixed effects model. Results: Of the 60 included participants (51.7% female; mean ± SD age, 25.4 ± 3.3 years; body mass index, 22.6 ± 2.1 kg·m-2), 53 completed the study (19 in the barefoot habituation group, 18 in the shod habituation group, and 16 in the passive control group). Acutely, running barefoot versus shod influenced foot strike index and ankle, foot, and knee angles at ground contact ( P < .001), as well as vertical average loading rate ( P = .003), peak force ( P < .001), contact time ( P < .001), flight time ( P < .001), step length ( P < .001), and cadence ( P < .001). No differences were found for average force ( P = .391). After the barefoot habituation period, participants exhibited more anterior foot placement ( P = .006) when running barefoot, while no changes were observed in the footwear condition. Furthermore, barefoot habituation increased the vertical average loading rates in both conditions (barefoot, P = .01; shod, P = .003) and average vertical ground-reaction forces for shod running ( P = .039). All other outcomes (ankle, foot, and knee angles at ground contact and flight time, contact time, cadence, and peak forces) did not change significantly after the 8-week habituation. Conclusion: Changing acutely from shod to barefoot running in a habitually shod population increased the foot strike index and reduced ground-reaction force and loading rates. After the habituation to barefoot running, the foot strike index was further increased, while the force and average loading rates also increased as compared with the acute barefoot running situation. The increased average loading rate is contradictory to other studies on acute adaptations of barefoot running. Clinical relevance: A habituation to barefoot running led to increased vertical average loading rates. This finding was unexpected and questions the generalizability of acute adaptations to long-term barefoot running. Sports medicine professionals should consider these adaptations in their recommendations regarding barefoot running as a possible measure for running injury prevention. Registration: DRKS00011073 (German Clinical Trial Register).
... A comprehensive quantitative gait assessment is clinically useful as gait could be one of the markers for disease progression, it can characterize and distinguish asymptomatic gait, and track various rehabilitation progresses [1]- [5]. In sports applications, gait assessment is useful in tracking the performance of athletes, preventing injury, and providing training advice [6]- [7]. Furthermore, in gerontology, gait assessment is used to predict the risk of falling in elderly people [8]- [9]. ...
Article
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The importance of gait analysis in medical applications, such as in rehabilitation, has been widely studied. Wearable sensors have gained popularity owing to their convenience of use in a flexible environment, while providing accuracy and reliability, in comparison with the gold standard system, i.e., motion capture. In this study, we proposed a framework for quantitative gait assessment using only two inertial measurement unit (IMU) sensors, while extracting maximum number of features. Decreasing the number of sensors negatively affects the performance of gait assessment. However, through comparison with a motion capture setup and previous studies, we verified the potential and limitations of our proposed framework toward providing a compact sensing system with feature-rich diversity for gait assessment. The results revealed that the temporal differences were 4.22±15.48 ms (mean ± S.D.) and -8.31±21.02 ms (mean ± S.D.) in the initial contact and toe-off events, respectively. Additionally, with respect to the spatial features, the stride length and heel vertical displacement were overestimated by an average of 7.72 cm and 2.22 cm, respectively. We successfully extracted 17 gait features from two IMUs located on the foot. We have also demonstrated that symmetry index feature can distinguish normal healthy subjects and subject with recent history of lower-limb injury, which is important for clinical research.
... Ground reaction force (GRF) on the sole is one of the factors used to clarify foot biomechanics [1,2]. A significant number of reports have evaluated the GRF using several methods, such as force plates (FPs) [3][4][5][6][7], treadmills [8][9][10], and attaching force sensors to shoe soles [11,12]. Among them, the FP system has been widely used due to its highaccuracy measurement in multiple directions without needing to be worn by the subject. ...
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This paper reports on a force plate (FP) using mechanical springs and noncontact distance sensors. The ground reaction force (GRF) is one of the factors for clarify biomechanics, and FPs are widely used to measure it. The sensor elements of conventional FPs are mainly strain gauges. Thus, the mechanical properties of FP depend on the sensor element performance. If the FP performance must change, we must redesign the FP, including changing the sensor elements. Here, we proposed an FP that uses a measuring principle based on simple springs and noncontact sensors. The shape and performance of the proposed FP are expected to change easily. As a prototype device, we designed and fabricated an FP installed with 12 springs and four sensors for human walking. A planar coil and magnet were used as the sensor elements, and the sensor output was proportional to the vertical and horizontal displacements. The FP resonance frequency was 123 Hz, which was larger than the required specification. The calibration experiments showed that vertical and horizontal forces and moments could be measured independently. The FP's resolutions were 1.9 N and 1.4 N in the anterior-posterior and vertical directions, respectively. Furthermore, the fabricated FP measured GRF similarly to the commercial FP when a human walked on the plate. These results suggest that the proposed method will be helpful for FPs with custom-made requirements.
... Gait analysis has wide applications ranging from sports to clinical investigations. In sports, gait analysis is often utilized to assess the performance of athletes, prevent injuries, and provide a training guide [1], [2]. In clinical applications, gait analysis is performed to characterize certain gait pathologies, track rehabilitation progress, and evaluate the effectiveness of certain treatments [3]- [5]. ...
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The current gold standard for gait analysis involves performing the gait experiments in a laboratory environment with a constrained space. However, there is growing interest in using flexible, efficient, and inexpensive wearable sensors as tools to perform gait analysis. This review aimed to identify and summarize the current advances in wearable sensors for various aspects of gait analysis, such as the application of wearable gait analysis systems, sensor systems and their attachment locations, and the algorithms used for the analysis. The PRISMA guideline was adopted to find relevant studies from the period 2011 to 2020 from several scientific databases. A total of 76 articles were selected based on the inclusion and exclusion criteria. A wearable inertial measurement unit (IMU) attached to the lower limb region was found to be the most common approach for gait analysis. Temporal, spatial, and spatiotemporal features were the most common quantitative gait features extracted from the wearable sensors. The proposed frameworks showed varying performances, and an increased number of sensors did not necessarily improve the estimation performance metrics. A few studies have integrated various machine learning techniques for classification problems, correction algorithms, crosschecking functions, and scoring functions. Finally, this review paper discusses the challenges and future direction of the research on quantitative gait analysis.
... When the impact forces become higher, muscles or joints cannot adequately dissipate the stresses, and there is a potential for sports injury [2]. Recent studies on injuries during sports have reported that the repetition of impact force might lead to increased injury risks [3,4]. ...
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Repeated high-impact ground forces can lead to injury and decreased performance. While increasing flexor hallucis longus (FHL) muscle activity is known to increase stiffness and elasticity, it is unknown if this also decreases ground reaction forces by shock absorption during landing. This study aimed to determine whether increasing FHL muscle activity affects ground reaction force during landing in healthy subjects. Eight subjects performed single-leg steps onto a force platform for five trials, with and without flexion of the metatarsophalangeal (MTP) joint at the moment of landing. Integrated surface electromyography (sEMG) of the FHL and medial gastrocnemius (MG) and ground reaction forces (GRFs) were measured. sEMG and GRF during the 50 ms before and 100 ms following initial ground contact were analyzed and compared. Flexion of the MTP joint condition significantly decreased the vertical and mediolateral force peaks of GRF, and FHL muscle activity increased. Flexion of the MTP joint at the moment of landing reduces GRF in healthy subjects through force dissipation in the foot, by increased FHL muscle activity. The results suggest that this may contribute to injury prevention by reducing the impact force through flexing the MTP joint at the moment of landing.
... The results of joint moments from the current study were also compared with recently published OpenSim running studies (Hamner and Delp 2013;Mei et al. 2019). Further, it should be noted that this study recruited runners who have no experience with barefoot running to control potential confounding factors due to reported differences in foot morphology and running biomechanics between habitual barefoot runners and shod runners (D'AoÛt et al. 2009;Hatala et al. 2013;Mei et al. 2015). Thus, some caution is needed when applying our results to habitual barefoot runners. ...
Article
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Barefoot running has been associated with lowered joint loading, but it remains unclear whether the biomechanical benefits are evident after mid-distance running. A musculoskeletal model was adopted for estimating lower limb joint loading for barefoot (n = 10) versus shod (n = 10) 5 km running. The barefoot group reduced peak joint reaction force at the hip and knee, and presented muscle force reductions compared to shod controls with significant group effects and interaction effects (p < .05). These changes were primarily group effects as time point effects were not significant. These findings should be considered when designing barefoot running shoes, running programmes, and injury prevention programmes.
... Furthermore, there are controversial findings of the effects of footwear on running biomechanics. Previous re-search studies indicated that shod running may decrease the injury risk in the lower extremities by attenuating vertical LR [7,8]. Nevertheless, other researchers have reported a reduction in GRF components with instructed barefoot running [9,10]. ...
Article
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Purpose: The current study aimed to evaluate the effects of barefoot and shod running with two different styles on ground reaction force-frequency content in recreational runners with low arched feet. Methods: The statistical sample of this research was 13 males with Pronated Feet (PF) (Mean±SD age: 26.2±2.8 y; height: 176.1±8.4 cm; weight: 78.3±14.3 kg). A force plate (Bertec, USA) with a sample rate of 1000 Hz was used to record the reaction forces under each foot. Three test conditions in our study included shod running with rearfoot, midfoot, and forefoot patterns. Repeated-measures Analysis of Variance (ANOVA) was used for analyzing the data. Results: During forefoot running, the research subjects attained 10% higher GRF values in vertical direction, compared with rearfoot running (P˂0.001, d=2.133). Forefoot running decreased the peak vertical GRF, compared to rearfoot running (by 12%, P=0.01, d=0.826). Barefoot running decreased the peak vertical GRF, compared to shod running (by 6%, P=0.027, d=1.143). The collected results revealed a significantly lower FyMed (P<0.02, d=1.11, 14%), Fy99.5% (P<0.02, d=0.11, 8%), and greater FyNe (P<0.02, d=0.72, 10%), Fz99.5% (P<0.01, d=4.30, 124%), and FzNe (P<0.01, d=1.65, 44%) when running with rearfoot strike pattern, compared with forefoot strike pattern. Conclusion: The study subjects with pronated feet experienced greater GRF values during forefoot running than rearfoot; such data may imply an increased risk of running injuries. Therefore, forefoot running is not recommended for runners with pronated feet.
... En esta misma línea, Mei et al. (2015) estudiaron a sujetos divididos según patrón de apoyo plantar, quienes corrieron a 3,0 m·s -1 en condiciones de calzado y descalzo, encontrando que los sujetos que habitualmente se mueven descalzos tienen menor área de superficie de apoyo en la zona medial del mediopié lo cual indica un MLFA de tipología cava, resultado que coincide con los cambios descritos en la distribución de tipología de pie, en donde los sujetos que corrieron descalzos tuvieron tendencia a modificar su arco plantar hacia un tipo cavo, en Post 20 min Run y Post 8 week Training. Shu et al. (2015) estudiaron a dos poblaciones de sujetos que normalmente corren a pie descalzo (indios) con otro grupo de corredores calzados (chinos), obteniendo como resultado que las mujeres del primer grupo tienen pies más largos y antepiés más anchos, lo cual podría ser una adaptación natural. ...
Article
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Barefoot running has been studied extensively recently, but little is known of the anatomical changes that take place in the foot. The objective of this study was to determine the acute and chronic changes that are produced in subjects who train barefoot. 29 subjects divided into two groups, Barefoot (BFGr) (n=17) and Shod (SGr) (n=12), followed an acute effect protocol which consisted in running during 20 min on a treadmill at 3.1 m/s, and an eight-week long chronic effect protocol covering eight weeks of resistance running with progressively increasing volume. BFGr did all the sessions barefoot. At the end of each protocol Foot Length (FL), Forefoot Width (FW), Hindfoot Width (HW), Navicular Height (NH), Arch Index (AI), and Maximum Surface (MS) were measured. ANOVA 3x2 was run to verify the effects caused by time and the shod condition produced. Shod/Unshod factor caused significant effects on all the variables (FL:p=0.000, h2p=0.997; FW: p=0.000, h2p=0,997; HW: p=0.000, h2p=0,994; NH: p=0.000, h2p=0.953; AI: p=0.000, h2p=0.898; MS:p=0.000, h2p=0.983), and the time factor on AI (p=0.012,h2p=0.152) and MS (p=0.000, h2p=0.259). There was a significant Time x Condition interaction in FW (p=0.036, h2p=0.116) and NH (p=0.019, h2p= 0.143). MS increased after the acute (p=0.000) and the chronic (p=0.001) protocols in the BFGr. The percentage of subjects with normal feet increased in the BFGr and that with flat feet increased in SGr. Barefoot running training causes effects, mainly after an adaptation period of eight weeks, tending to a harmonic surface increase on the support plantar area, with a relative decrease of the midfoot area, which meant a decrease of subjects with plantar arch of flat type.
... Barefoot runners typically adopt a forefoot strike technique, which likely causes increased loading under the lateral forefoot. The findings from the current study are consistent with previous barefoot running studies, reporting greater peak pressure under the lateral forefoot during barefoot running when compared to shod running (Bergstra et al., 2015;Mei et al., 2015). Further, the plantar pressure under the lateral edge of the metatarsals was shown to be higher in habitual barefoot walkers than shod walkers, suggesting greater load bearing under the lateral forefoot (D'AoÛt et al., 2009), although walking and running are biomechanically very different. ...
Article
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Barefoot running has been increasing in popularity, yet there is a gap in understanding concerning the biomechanics of mid-distance barefoot running, especially between genders and runners of different running-experience levels. This study examines the effects of running-experience, gender, and their interaction on running biomechanics following 5 km barefoot running. Before and after a 5 km run, three-dimensional kinematics and kinetics of the lower limb joints and plantar pressure during barefoot running were collected from 20 participants. Participants were stratified by their running-experience levels (novice and marathon-experienced) and gender. This study revealed significant gender effects on lower limb biomechanics following a 5 km barefoot run. Increased plantar pressure under the lateral aspect of the foot was observed in the female cohort, while the male cohort exhibited reduced plantar pressure under the lateral heel. This study suggests that modified lower limb running biomechanics and modified lateral foot loading after 5 km barefoot running may create a different foot loading environment for female and male runners that should be accommodated in barefoot running and minimalist shoe design.
... The different GRF trajectories of HBM and HSM in this study indicated that there were different force mechanisms between HBM and HSM in take-off phase. Existing study proved that the feature of foot morphology was associated with the lower-limb biomechanical variation (Werkhoven et al, 2017); the distance between hallux toe and other toes and the toe length can all increase push force of foot during running, sprint and jump (Shu et al., 2016;Lee et al., 2009;Mei et al., 2015). For instance, Shu et al (2016) has found that HBM showed higher plantar loading under hallux and medial forefoot and HSM showed higher plantar loading under medial and central forefoot. ...
Conference Paper
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The aim of this study was to explore the kinematic variations in knee and ankle joints and the ground reaction force between habitually barefoot (HBM) and shod males (HSM) during countermovement jump. Twenty-eight males (14 HBM,14 HSM) participated in this experiment. An 8-camera Vicon motion system was used to collect the kinematic data of knee and ankle joints from 3 dimensions and the force plate was used to collect the ground reaction force in take-off phase. Results in take-off phase showed that HSM produced two peak forces to take off and showed significantly greater knee ROM in sagittal plane, as well as greater ankle inversion and external rotation. In conclusion, the foot morphological differences can result in the different influence on jump performance. The relevant practioner should pay close attention to the effect of foot morphology on jump in training.
... This allows us to ponder that if the training effect alone was the main one, the changes would have been the same in both groups, a situation that did not occur. The decrease of the duration time of TFC has been reported frequently in research dealing with the acute effect of running barefoot (De Wit, De Clercq & Aerts, 2000;Mei et al., 2015;Fleming et al., 2015;Lieberman et al., 2015), an aspect that could be verified in this research, although not with significant effects in BFGr. In the long term however, it was shown that the duration time of total TFC in both groups increased in time, but only in the group that trained barefoot this 33.3% ...
Article
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Background Although the studies of barefoot running have intensified, it is still missing longitudinal work analyzing the effects of barefoot running on the phases of plantar support. The objective of this research was to analyze the modifications undergone by the Total Foot Contact (TFC) phase and its Flat Foot Phase (FFP) in subjects beginning the practice of barefoot running, in its acute and chronic effects. Methods A total of 28 subjects were divided into the Barefoot Group (BFGr) ( n = 16) and the Shod Group (SHGr) ( n = 12), evaluated before (Baseline) and after running for 20 min at 3.05 m·s ⁻¹ (Post 20 min Running), and at the end of a running training protocol with an 8-week long progressive volume (Post-8-week Training). The dynamic plantar support was measured with a baropodoscope. The duration of TFC (ms), the moment at which the FFP occurred, the maximum surface of TFC (MSTFC) (cm ² ), the FFP surface (SFFP) (cm ² ), the peak pressure of TFC (PP°TFC) (kg·cm ⁻² ), and the peak pressure of FFP (PP°FFP) (kg·cm ⁻² ) were recorded. The 3 × 2 ANOVA analysis was made to determine the effects and interactions that the condition produced (Shod/Barefoot), and the time factor (Baseline/Post 20 min Running/Post-8-week Training). Results The condition factor caused more significant effects than the time factor in all the variables. Duration of TFC in BFGr showed significant differences between the Baseline and Post-8-week Training ( p = 0.000) and between Post-20-min Running and Post-8-week Training ( p = 0.000), with an increasing trend. In the moment at which the FFP occurred a significant increase ( p = 0.029) increase was found in Post-20 min Running (48.5%) compared to the Baseline (42.9%). In MSTFC, BFGr showed in Post-8-week Training values significantly higher than the Baseline ( p = 0.000) and than Post-20-min Running ( p = 0.000). SHGr presented a significant difference between the Baseline and Post-8-week Training ( p = 0.040). SFFP in BFGr modified its values with an increasing trend ( p = 0.000). PP°TFC in BFGr showed a significant decrease ( p = 0.003) in Post-8-week Training (1.9 kg·cm ⁻² ) compared to the Baseline (2.4 kg·cm ⁻² ). In PP°FFP significant decreases were recorded in BFGr and between Post-8-week Training and Baseline ( p = 0.000), and Post-8-week Training and Post 20 min Running ( p = 0.035). Conclusions The adaptation took place after the 8-week training. The adaptations to running barefoot were characterized by causing an increase of the foot’s plantar support in TFC and in FFP, as well as a decrease of the plantar pressure peak in both phases. Also, there is an increased duration of the TFC and FFP, which may be related to an acquired strategy to attenuate the impacts of the ground’s reaction forces.
... Keywords: 3D Statistical Shape Modelling, Foot shape, Shoe Last, Principal Component Analysis 统计形状模型(Statistical Shape Model,SSM)主要是描述可变形物体(Deformable Object) 的形态学变化 [1,2] 。当前,随着工程技术、计算机视觉与医学影像等科技的快速发展及跨学 科应用,二维与三维统计形状建模分析算法的不断优化及精准度的提高 [3][4][5] ,统计形状建模 技术已在面部性别识别 [6] 、考古学数据复原 [7] 、脊柱二维数据向三维形态的配准 [8] 及构建可 缩放且解剖标志准确的三维参数化脊柱有限元模型用于快速评估并指导临床治疗 [9] 、三维肝 脏分割手术临床指导 [10] 及骨骼与关节的形态和功能间关联性评估等研究中不断增多。总结 上述各相关研究与应用,采用的基本流程大体相似:首先通过获取二维或三维形态模型,医 学三维模型主要均源于 CT/MRI 影像数据的重建 [1,2] [11,12] 对三维表面足型进行扫描, 设备分辨率及平滑系数分别设定 [13,14] 的相关研究中有详细介绍,本研究仅在下文中作简要关键步骤介绍。 [17,18] ,前期研究已 揭示了其他的相关因素,如有无鞋具(裸足或着鞋)习惯、特殊鞋具(如高跟鞋、芭蕾舞鞋 及职业特殊鞋具)及长期特定运动的习惯对足形态的适应性影响 [11,19,20] ,且会出现相应不同 的生物力学表现 [21,22] 。然而,前期均是大量关于足的二维形态研究,譬如足长、足宽、足弓 ...
Article
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Objective: It was aimed to reveal the foot shape variations in three dimension via the 3D statistical shape modelling. Methods: Fifty feet of normal Chinese young males were used build the statistical shape model. Steps, including mesh registration of foot surface, axis alignment and principal component analysis (dimension reduction), were performed to obtain the parameterized foot shape (mean shape and standard deviation of principal components). Results: Through the principal component analysis (PCA), the 3D foot shape varies in the length and width (PC1, 48.01%), arch and dorsal height (PC2, 11.38%), and hallux abduction-adduction position (PC3, 7.48%). Conclusions: Based on the parameterised 3D foot statistical shape modelling, these dataset could be applied into the population-based shoe last manufacture, orthotics customization and quick diagnosis of foot disorders in clinics.
... The marker trajectories and force platform data were recorded synchronously using the Vicon Nexus 1.8.5. During walking and running, the gait cycle per trial was defined that the left foot successively contacting the ground twice [34]. ...
... Participants were instructed to walk at a self-selected comfortable walking speed. During the per walking test, the gait cycle was defined as consecutive heel strikes of the ipsilateral foot [32]. Six acceptable trials were completed for each subject. ...
Article
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Spinal orthoses are an effective option for restoring the spine to its original position and controlling poor posture. However, the effects of poor posture and spinal orthoses on the kinematics and kinetics of trunk and lower extremity joints remain unclear. A six-camera Vicon motion capture system and two AMTI force plates were employed to collect gait parameters, including joint angle (spine, thorax, hip, knee, and ankle), range of motion (ROM), and ground reaction forces (GRFs). Furthermore, joint moments and joint reaction forces (JRFs) were calculated using a full-body musculoskeletal model in OpenSim. One-way repeated-measures ANOVA (p < 0.05) was used to compare significant differences among three trial conditions. These three conditions were walking in a normal posture, poor posture, and spinal orthosis. The results showed that spine ROM in the coronal and transverse plane was significantly lower when walking with a spinal orthosis compared to walking in normal and poor posture (p < 0.05). Compared to normal posture, the lumbar moments and back compressive forces were significantly increased when walking in poor posture (p < 0.05). However, when walking with a spinal orthosis, there was a significant decrease in trunk moments and reaction forces compared to walking in poor posture (p < 0.05). Individuals with poor posture could potentially induce instability and disorders, as evidenced by an increase in trunk moments and JRF compared to the normal posture. Spinal orthosis not only restricts spine ROM but also reduces the load on the spine and thus increases balance and stability.
... En esta misma línea, Mei et al. (2015) estudiaron a sujetos divididos según patrón de apoyo plantar, quienes corrieron a 3,0 m·s -1 en condiciones de calzado y descalzo, encontrando que los sujetos que habitualmente se mueven descalzos tienen menor área de superficie de apoyo en la zona medial del mediopié lo cual indica un MLFA de tipología cava, resultado que coincide con los cambios descritos en la distribución de tipología de pie, en donde los sujetos que corrieron descalzos tuvieron tendencia a modificar su arco plantar hacia un tipo cavo, en Post 20 min Run y Post 8 week Training. Shu et al. (2015) estudiaron a dos poblaciones de sujetos que normalmente corren a pie descalzo (indios) con otro grupo de corredores calzados (chinos), obteniendo como resultado que las mujeres del primer grupo tienen pies más largos y antepiés más anchos, lo cual podría ser una adaptación natural. ...
Article
Full-text available
Barefoot running has been studied extensively recently, but little is known of the anatomical changes that take place in the foot. The objective of this study was to determine the acute and chronic changes that are produced in subjects who train barefoot. 29 subjects divided into two groups, Barefoot (BFGr) (n=17) and Shod (SGr) (n=12), followed an acute effect protocol which consisted in running during 20 min on a treadmill at 3.1 m/s, and an eight-week long chronic effect protocol covering eight weeks of resistance running with progressively increasing volume. BFGr did all the sessions barefoot. At the end of each protocol Foot Length (FL), Forefoot Width (FW), Hindfoot Width (HW), Navicular Height (NH), Arch Index (AI), and Maximum Surface (MS) were measured. ANOVA 3x2 was run to verify the effects caused by time and the shod condition produced. Shod/ Unshod factor caused significant effects on all the variables (FL: p=0.000, η2p=0.997; FW: p=0.000, η2p=0,997; HW: p=0.000, η2p= 0,994; NH: p=0.000, η2p=0.953; AI: p=0.000, η2p=0.898; MS: p=0.000, η2p=0.983), and the time factor on AI (p=0.012, η2p=0.152) and MS (p=0.000, η2p=0.259). There was a significant Time x Condition interaction in FW (p=0.036, η2p=0.116) and NH (p=0.019, η2p= 0.143). MS increased after the acute (p=0.000) and the chronic (p=0.001) protocols in the BFGr. The percentage of subjects with normal feet increased in the BFGr and that with flat feet increased in SGr. Barefoot running training causes effects, mainly after an adaptation period of eight weeks, tending to a harmonic surface increase on the support plantar area, with a relative decrease of the midfoot area, which meant a decrease of subjects with plantar arch of flat type.
... The main intrinsic factors for the development of PF in runners have been explained as foot-type changes 12 , rearfoot valgus posture 4,13,14 , and elevated plantar arch structures 5,8,13 . Understanding the foot structure has been the main focus of clinicians to prevent injuries in runners, helping them to choose the correct footwear and providing the appropriate interventions 15 . These are directed towards improving the synaptic tactile afferents from the fascia and the motor neurons supplying the leg muscles 1,16 . ...
Article
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Background: The risk factors for the development of plantar fasciitis (PF) have been associated with the medial longitudinal arch (MLA), rearfoot alignment and calcaneal overload. However, the relationships between the biomechanical variables have yet to be determined. Objective: The goal of this study was to investigate the relationships between the MLA, rearfoot alignment, and dynamic plantar loads in runners with unilateral PF in acute and chronic phases. Method: Cross-sectional study which thirty-five runners with unilateral PF were evaluated: 20 in the acute phase (with pain) and 15 with previous chronic PF (without pain). The MLA index and rearfoot alignment were calculated using digital images. The contact area, maximum force, peak pressure, and force-time integral over three plantar areas were acquired with Pedar X insoles while running at 12 km/h, and the loading rates were calculated from the vertical forces. Results: The multiple regression analyses indicated that both the force-time integral (R2=0.15 for acute phase PF; R2=0.17 for chronic PF) and maximum force (R2=0.35 for chronic PF) over the forefoot were predicted by an elevated MLA index. The rearfoot valgus alignment predicted the maximum force over the rearfoot in both PF groups: acute (R2=0.18) and chronic (R2=0.45). The rearfoot valgus alignment also predicted higher loading rates in the PF groups: acute (R2=0.19) and chronic (R2=0.40). Conclusion: The MLA index and the rearfoot alignment were good predictors of plantar loads over the forefoot and rearfoot areas in runners with PF. However, rearfoot valgus was demonstrated to be an important clinical measure, since it was able to predict the maximum force and both loading rates over the rearfoot.
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Embora o uso de um calçado faça parte do dia a dia da maioria das pessoas, ao avaliar o controle postural na postura em pé, muitos estudos consideram uma condição descalço. Assim, as pessoas diariamente convivem com uma condição onde utilizam calçados, e são avaliadas em uma condição diferente. A justificativa muitas vezes é que o calçado pode influenciar a avaliação. Contudo, pode o calçado habitual de fato influenciar o controle postural estimado pela trajetória do centro de pressão? Para responder a esta pergunta, avaliamos 14 adultos jovens com média de idade de 23 ± (4) anos, estatura de 1,63 ± (0,05) m e massa corporal de 59 ± (7) kg. Eles mantiveram a posição em pé, com apoio bipodal, com e sem usar o seu próprio calçado, com olhos abertos e fechados. Uma plataforma de força foi utilizada para aquisição de forças e momentos de reação do solo. Os dados foram utilizados para o cálculo do centro de pressão. Nenhuma das variáveis do centro de pressão (amplitudes, área e velocidade) diferiu entre as condições calçado e descalço, tanto com olhos abertos quanto fechados. Em resumo, o calçado habitual não influenciou as amplitudes de oscilação do centro de pressão durante a postura em pé.
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The growing popularity of endurance sports activities is associated with a growing number of running injuries among recreational runners. The aim of this study was to assess the kinematic and kinetic variation on biomechanical parameters before and after 5km of treadmill running in female runners. Fourteen habitually shod female runners were assessed during treadmill running at their self-selected 5km running speed. A VICON motion analysis system and a Novel Pedar insole plantar pressure measurement system were used to record kinematic and plantar pressure data. Key findings from the study were that the internal and external rotation angle of the ankle, hip and knee while pre-5k running showed significant differences to those evaluated post-5k. The peak values of ground reaction forces (GRF) recorded pre-5k running were larger than the forces measured post-5k running. Combining the inversion and eversion of the ankle in the coronal plane during the pushing off phase, post-5k running showed a bigger eversion angle than pre-5k running. These subtle differences may reflect adaptation of motor control in female runners during long distance running of 5km.
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Hallux valgus is a foot pathological condition showing a lateral deviation of the first phalange and medial deviation of the first metatarsal. The purpose of the current study was to evaluate a longitudinal effect of minimalist footwear running protocol for a mild/moderate hallux valgus patient. The computer tomography (CT) images from a male hallux valgus (HV) patient were respectively scanned pre and post 12-week minimalist footwear running intervention. The pre and post -intervention foot finite element (FE) models were developed from the foot three-dimensional geometries manually segmented via the MIMICS 21.0. The post-process with SolidWorks 2019 was conducted for model assembly, consisting of 24 bones, 22 cartilages, five plantar fascia, and lumped encapsulated soft tissue. The foot FE models were solved in ANSYS Workbench 2020 R1 package. The FE models were validated against the plantar pressure (pre: 0.146MPa vs 0.155MPa, and post: 0.156MPa vs 0.17MPa) and vertical displacements (pre: 2.6 mm vs 2.4±0.4mm, and post 1.1mm vs 1.3 ± 0.4mm) of navicular measured from experiments. The first metatarsophalangeal joint showed varus realignment and the von Mises stress in the first metatarsal and the second metatarsal decreased 72.1% and 51.2% compared with pre-intervention (M1: 4.41 MPa and M2, 4.18 MPa). This framework investigated the shape adjustment and functional recovery in the mild/moderate HV deformity, which may provide references and implications for future studies with a larger cohort.
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The human foot was anatomically modern long before footwear was invented, and is adapted to barefoot walking on natural substrates. Understanding the biomechanics of habitually barefoot walkers can provide novel insights both for anthropologist and for applied scientists, yet the necessary data is virtually non-existent. To start assessing morphological and functional effects of the habitual use of footwear, we have studied a population of habitually barefoot walkers from India (n ¼ 70), and compared them with a habitually shod Indian control group (n ¼ 137) and a Western population (n ¼ 48). We focused on foot metrics and on the analysis of plantar pressure data, which was performed using a novel, pixel based method (Pataky and Goulermas 2008, Journal of Biomechanics, 41, 2136). Habitually shod Indians wore less often, and less constricting shoes than Western people. Yet, we found significant differences with their habitually barefoot peers, both in foot shape and in pressure distribution. Barefoot walkers had wider feet and more equally distributed peak pressures, i.e. the entire load carrying surface was contributing more uniformly than in habitually shod subjects, where regions of very high or very low peak pressures were more apparent. Western subjects differed strongly from both Indian populations (and most from barefoot Indians), by having relatively short and, especially, slender feet, with more focal and higher peak pressures at the heel, metatarsals and hallux. The evolutionary history of humans shows that barefoot walking is the biologically natural situation. The use of footwear remains necessary, especially on unnatural substrates, in athletics, and in some pathologies, but current data suggests that footwear that fails to respect natural foot shape and function will ultimately alter the morphology and the biomechanical behaviour of the foot.
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Background Investigations of running gait among barefoot and populations have revealed a diversity of foot strike behaviors, with some preferentially employing a rear-foot strike (RFS) as the foot touches down while others employ a mid-foot strike (MFS) or fore-foot 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) 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% and 85.7% of women and juveniles, respectively). No FFS were recorded. Speed, the presence of footwear (sandals versus 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.
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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 patterns are 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 18 remaining 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. All FFS runners activated their plantarflexor muscles 11% earlier and 10% longer than RFS runners. Conclusion This earlier and longer relative activation of the plantarflexors 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-bridges and activated titin.
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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 been associated with certain running related injuries, specifically, tibial stress fractures, patellofemoral pain, and plantar fasciitis. 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 ground reaction forces (p < 0.0001) 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.
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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.
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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 of BF running and running in a minimal running shoe (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 an 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 Barefoot 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.
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Postural control has been defined as the control of the body's position in space for the purposes of balance and orientation. Given the mechanical instability of the human body system, the neural process involved in stability organization and body orientation in space is necessary almost all motor actions. To manage movement variability, the postural control system presents a high adaptability in response to changing task and environment demands. The main sensory systems contribute to the development of an internal representation of body posture that is continuously updated based on multisensory feedback and is used to forward commands to control body position in space. For example, understanding the importance of proprioceptive information, and how ankle muscles can influence changes of support and stability that could improve postural control is of significant relevance. The purpose of this chapter is to review and discuss the short and long term influence of wearing an unstable shoe construction on postural control. The review provides instinctive knowledge that can be used during rehabilitation to improve motor performance. It also aims to provide a significant insight into areas that have been dedicated to the implementation of preventive measures, such as ergonomy.
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There is currently no consensus regarding the effect that barefoot (BFT) running has on running economy (RE). Stride length and shoe mass are confounding variables, with a BFT stride length being shorter than a shod (SH) stride length. Comparison of SH, minimalist shod (MS) and BFT allows controlled variation of cushioning and somatosensory feedback to determine the effect that either and/or both have on RE and running mechanics. Methods: Fifteen female habitually shod, recreational runners visited the laboratory twice. Familiarisation with BFT and SH treadmill running occurred during visit one, in addition to determining SH stride length and BFT stride length. During visit two participants ran BFT, SH and MS with BFT stride length and MS with SH stride length at 10 km·h?1 for six minutes with 10-minute rest periods between each condition. Lower limb kinematics, electromyography, impact acceleration and O2 were recorded during the final two minutes of each run. Results: BFT RE was significantly better than SH and MS with BFT stride length. SHRE was significantly worse than MS with SH stride length, but similar to MS with a BFT stride length. Low vertical oscillation, peak eversion and peak dorsiflexion, less plantarflexion at toe-off, in addition to an earlier occurrence of heel off, higher impact accelerations and greater tibialis anterior activity were observed during the most economical condition. Conclusions: Heightened somatosensory feedback and lack of cushioning (BFT) offered an advantage to economy over less somatosensory feedback (MS) and cushioning (SH). Whilst the low vertical oscillation and low plantarflexion at toe-off appear to contribute to the improved RE, other changes to running mechanics whilst BFT could potentially influence injury risk.
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Barefoot running has become a popular research topic, driven by the increasing prescription of barefoot running as a means of reducing injury risk. Proponents of barefoot running cite evolutionary theories that long-distance running ability was crucial for human survival, and proof of the benefits of natural running. Subsequently, runners have been advised to run barefoot as a treatment mode for injuries, strength and conditioning. The body of literature examining the mechanical, structural, clinical and performance implications of barefoot running is still in its infancy. Recent research has found significant differences associated with barefoot running relative to shod running, and these differences have been associated with factors that are thought to contribute to injury and performance. Crucially, long-term prospective studies have yet to be conducted and the link between barefoot running and injury or performance remains tenuous and speculative. The injury prevention potential of barefoot running is further complicated by the complexity of injury aetiology, with no single factor having been identified as causative for the most common running injuries. The aim of the present review was to critically evaluate the theory and evidence for barefoot running, drawing on both collected evidence as well as literature that have been used to argue in favour of barefoot running. We describe the factors driving the prescription of barefoot running, examine which of these factors may have merit, what the collected evidence suggests about the suitability of barefoot running for its purported uses and describe the necessary future research to confirm or refute the barefoot running hypotheses.
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This study investigated the influence of wearing unstable shoe construction (WUS) on compensatory postural adjustments (CPA) associated with external perturbations. Thirty-two subjects stood on a force platform resisting an anterior-posterior horizontal force applied to a pelvic belt via a cable, which was suddenly released. They stood under two conditions: barefoot and WUS. The electromyographic (EMG) activity of gastrocnemius medialis, tibialis anterior, rectus femoris, biceps femoris, rectus abdominis, and erector spinae muscles and the center of pressure (CoP) displacement were acquired to study CPA. The EMG signal was used to assess individual muscle activity and latency, antagonist co-activation and reciprocal activation at joint and muscle group levels. Compared to barefoot, WUS led to: (1) increased gastrocnemius medialis activity, (2) increased total agonist activity, (3) decreased antagonist co-activation at the ankle joint and muscle group levels, (4) increased reciprocal activation at the ankle joint and muscle group levels, and (5) decrease in all muscle latencies. No differences were observed in CoP displacement between conditions. These findings demonstrate that WUS led to a reorganization of the postural control system associated to improved performance of some components of postural control responses.
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Barefoot or minimal footwear running is currently a highly debated topic among runners and researchers. Several footwear companies have developed minimal running footwear to simulate barefoot running but few studies have compared minimal footwear to barefoot and shoes during running. The primary goal of this study was to compare acute changes in three-dimensional (3D) ground reaction forces (GRFs) and lower limb kinematics and kinetics of habitually shod rearfoot strike (RFS) and forefoot strike (FFS) runners between minimal shoes (MSH), barefoot and neutral cushion running shoes (SH). Lower extremity joint biomechanical variables of RFS and FFS runners were analysed using a 3D motion capture system and a force platform during overground running in barefoot, MSH and running shoes. Barefoot and MSH showed a more anterior foot strike than shoes. The loading rate of the impact peak GRF was greater in barefoot and MSH than in shoes. MSH showed greater ankle plantarflexor moment and negative power in early stance compared to shoes, which indicates greater eccentric plantarflexor muscle involvement in MSH than in shoes. Running shoes had greater peak knee extensor moment, early stance eccentric knee power and late stance concentric knee power compared to MSH and barefoot indicating less knee joint involvement. The current findings only pertain to acute changes between shoe conditions, and therefore training interventions in minimal footwear are warranted to further understand the adaptation effects of shod to barefoot or RFS to FFS running on lower limb biomechanics and running performance.
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This research aims to identify design attributes of a new generation running shoe by relating key performance parameters to the requirements of a specific user group. This paper considers the first phase of the research, comprising user group profiling, as well as the selection and subjective quantification of appropriate performance variables for targeted user groups. Three user groups have been defined, with the key functional performance attributes identified and prioritised for each. Using this information it has been possible to form the basis of a functional design specification for a shoe that should be best suited to the needs of runners within the target user group.
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This study investigated the influence of long-term wearing of unstable shoes (WUS) on compensatory postural adjustments (CPA) to an external perturbation. Participants were divided into two groups: one wore unstable shoes while the other wore conventional shoes for 8 weeks. The ground reaction force signal was used to calculate the anterior-posterior (AP) displacement of the centre of pressure (CoP) and the electromyographic signal of gastrocnemius medialis (GM), tibialis anterior (TA), rectus femoris (RF) and biceps femoris (BF) muscles was used to assess individual muscle activity, antagonist co-activation and reciprocal activation at the joint (TA/GM and RF/(BF+GM) pairs) and muscle group levels (ventral (TA+RF)/dorsal (GM+BF) pair) within time intervals typical for CPA. The electromyographic signal was also used to assess muscle latency. The variables described were evaluated before and after the 8-week period while wearing the unstable shoes and barefoot. Long-term WUS led to: an increase of BF activity in both conditions (barefoot and wearing the unstable shoes); a decrease of GM activity; an increase of antagonist co-activation and a decrease of reciprocal activation level at the TA/GM and ventral/dorsal pairs in the unstable shoe condition. Additionally, WUS led to a decrease in CoP displacement. However, no differences were observed in muscle onset and offset. Results suggest that the prolonged use of unstable shoes leads to increased ankle and muscle groups' antagonist co-activation levels and higher performance by the postural control system.
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The purpose of this study was to compare differences in knee and ankle kinematic and spatio-temporal variables at foot strike between barefoot and shod running. Twelve male runners (age 21.6±1.26 years) performed six running trials in each running condition on a 12m indoor runway at a self-selected pace. Lower limb kinematics and spatio-temporal variables were recorded with a six-camera T10 Vicon motion capture system (200Hz). In the barefoot condition runners landed with significantly greater knee flexion (p<0.01; ES=2.61) and less ankle dorsi-flexion (p<0.05; ES=1.12) compared to in the shod condition. No significant differences were found between knee varus/adduction (ES=0.78) or ankle inversion/adduction (ES=0.85) between the barefoot and shod conditions. The barefoot condition had significantly shorter contact time (p<0.01; ES=1.99) and step time (p<0.05; ES=1.13), while significantly higher step frequency (p<0.05; ES=1.25) compared to in the shod condition. Results indicated that immediate adaptations occurred when transitioning from shod running to barefoot running.
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Aim: The purpose of this study was to determine the changes in running mechanics that occur when highly trained runners run barefoot and in a minimalist shoe, and specifically if running in a minimalist shoe replicates barefoot running. Methods: Ground reaction force data and kinematics were collected from 22 highly trained runners during overground running while barefoot and in three shod conditions (minimalist shoe, racing flat and the athlete's regular shoe). Three-dimensional net joint moments and subsequent net powers and work were computed using Newton-Euler inverse dynamics. Joint kinematic and kinetic variables were statistically compared between barefoot and shod conditions using a multivariate analysis of variance for repeated measures and standardised mean differences calculated. Results: There were significant differences between barefoot and shod conditions for kinematic and kinetic variables at the knee and ankle, with no differences between shod conditions. Barefoot running demonstrated less knee flexion during midstance, an 11% decrease in the peak internal knee extension and abduction moments and a 24% decrease in negative work done at the knee compared with shod conditions. The ankle demonstrated less dorsiflexion at initial contact, a 14% increase in peak power generation and a 19% increase in the positive work done during barefoot running compared with shod conditions. Conclusions: Barefoot running was different to all shod conditions. Barefoot running changes the amount of work done at the knee and ankle joints and this may have therapeutic and performance implications for runners.
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Postural balance is vital for safely carrying out many daily activities, such as locomotion. The purpose of this study was to determine how changes in normal standing (NS) and standing with toe-extension (SWT) impact postural control during quiet standing. Furthermore, the research aimed to examine the extent to which the effect of these factors differed between genders. Thirty healthy young adults (age = 21.2±1.3 y; height = 1.63±0.07 m; mass = 56.0±9.3 kg) with no prior lower limb injuries participated in the study. A postural stability test using the Biodex Balance System was used for both NS and SWT conditions. The three measurements from the BBS were Overall Stability Index (OSI), Medial-Lateral Stability Index (MLSI) and Anterior-Posterior Stability Index (APSI). No significant difference was found between NS and SWT in the OSI, MLSI or APSI (F(2, 28) = 3.357, p = 0.077). The main difference between the stability index scores was significant (F(2, 28) = 275.1, p<0.001). The Bonferroni post-hoc test showed significant differences between the OSI and MLSI (p<0.001); the OSI and APSI (p<0.001); and the MLSI and the APSI (p<0.001). Significant differences were found during NS (p<0.001), for the MLSI when compared with the APSI, but this was not found during the SWT condition. Additionally, no gender effects were proven to exist that altered postural sway during quiet standing. This study reveals significant interaction between the stability indices measured; OSI, APSI and MLSI in both NS and SWT. Standing with toe extended does not have a significant impact on an individual's ability to control their balance during normal quiet standing. However, the findings revealed that the sway tendency in the medial-lateral direction might serve as a factor in an individual's ability to regain balance.
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Good fitting footwear requires matching not just the linear dimensions of feet but their girths as well. Footwear fitters have been using manual measurements for a long time, but the development of computerized techniques and scanner technologies have now made automatic determination of different foot dimensions feasible. The resistance to using such computer measurements has been the lack of trust in the accuracy of the data. This paper proposes an approach to obtain the necessary girths of feet in order to customize footwear. The proposed approach attempts to simulate the manual measurement procedures, and its effectiveness is assessed through an experiment with 15 foot castings. The results show that the simulated measurements can be within 5 mm of the manual measurements if the measuring locations can be correctly identified. Linear regressions show that the differences between the manual measurements and the simulated measurements can be modeled with the addition of a systematic error term of less than 4 mm. The computerized acquisition of foot dimensions is a useful way forward for custom shoe manufacturers.