The interaction effect of different footwear types and static navicular drop or dynamic ankle pronation on the joint stiffness of the lower limb during running

BACKGROUND

Although the effects of footwear type on joint stiffness have previously been investigated, researchers did not consider foot flexibility. Thus, the present investigation aimed to determine the interaction effects of footwear type, static navicular drop and dynamic ankle pronation on dynamic joint stiffness in running.

RESEARCH QUESTION

Does the footwear types in interaction with the foot posture affect the stiffness of the joints of the lower limb?

METHODS

Forty-seven male individuals participated in this study. Firstly, they were divided into the high navicular, low navicular, and normal navicular drop. Secondly, they were divided into the high dynamic ankle pronation, low dynamic ankle pronation, and normal dynamic ankle pronation groups. Participants performed three running trials at 3 ± 0.2 m/s at minimalist footwear, conventional footwear, and barefoot conditions. We collected the ground reaction forces and three-dimensional kinematic data and calculated joint stiffness over the stance phase.

RESULTS

There was no significant main effect of navicular drop or dynamic ankle pronation on dynamic joint stiffness for the ankle, knee, and hip (p > 0.05). However, footwear type significantly affected dynamic joint stiffness. The pairwise comparison revealed that the ankle and hip dynamic joint stiffness magnitudes in the conventional footwear condition were greater than in the barefoot and minimalist footwear conditions (p 0.001). In contrast, the knee dynamic joint stiffness magnitude in the conventional footwear condition was lesser than in barefoot and minimalist footwear conditions (p 0.001).

SIGNIFICANCE

The navicular drop or dynamic ankle pronation did not influence lower limb joint stiffness, and there was no significant interaction between navicular drop or dynamic ankle pronation and footwear on lower limb dynamic joint stiffness. However, conventional footwear increased the ankle and hip dynamic joint stiffness while reducing knee dynamic joint stiffness, leading to changes in transfer energy, which could have implications for relative injury risk.

Larger Achilles and plantar fascia induce lower duty factor during barefoot running

OBJECTIVES

Tendons play a crucial role allowing the storage and release of mechanical energy during the running cycle. Running kinematics, including duty factor, constitute a basic element of the runner's biomechanics, and can determine their performance. This study aimed to analyze the link between Achilles tendon and plantar fascia morphology and running parameters, considering the influence of wearing shoes versus running barefoot.

DESIGN

Cross-sectional study.

METHODS

44 participants (30 men and 14 women) engaged in two running sessions, one with shoes and one without, both lasting 3 min at a consistent speed of 12 km/h. We captured running kinematic data using a photoelectric cell system throughout the sessions. Before the trials, we measured the thickness and cross-sectional area of both the Achilles tendon and plantar fascia using ultrasound.

RESULTS

The Pearson test revealed a significant correlation (p < 0,05) between Achilles tendon and plantar fascia morphology and contact time (r > -0.325), flight time (r > -0.325) and duty factor (ratio of ground contact to stride time) (r > -0.328) during barefoot running. During the shod condition, no significant correlation was found between connective tissue morphology and kinematic variables.

CONCLUSIONS

In barefoot running, greater size of the Achilles tendon and plantar fascia results in a reduced duty factor, attributed to longer flight times and shorter contact times.

Differences in the center of pressure movement during standing with running shoes of different constructions: A cross-sectional study

Purpose

This study examined the differences in the center of pressure movement in a one-leg standing position with bare feet, thin-soled shoes, and thick-soled shoes.

Methods

In total, 21 male university students participated in this study. The task involved standing on one leg with the dominant foot for 30 s, and the center of pressure movement was measured using a grab coder (G-620; ANIMA, Tokyo, Japan). Three shoe-wearing states, including bare feet, thin-soled shoes, and thick-soled shoes, with the eyes closed and open in each condition. Statistical analysis was performed, with the significance level set as 5%.

Results

In the multiple comparison results, the anteroposterior (AP) locus length, AP locus length per second, and maximum amplitude in the AP direction were significantly larger with thick-soled shoes than with bare feet in the closed eyes state. The locus length per unit area was significantly smaller with the thick-soled shoes than with the barefoot condition. Other items did not differ significantly between the shoe-wearing states.

Conclusion

Thick-soled shoes caused a greater center of pressure movement in the AP direction in the static one-leg standing position than did the barefoot state. Our findings suggest that the condition with thick-soled shoes was more unstable in static environments.

The use of preferred footwear versus barefoot conditions in gait analysis: A methodological investigation

Laboratory-based gait analyses traditionally analyze baseline characteristics in individuals while they are barefoot. However, there is limited evidence on whether individuals' preferred walking shoes alter lower extremity kinematics during over-ground walking. We present novel evidence regarding the effects of shoes on lower extremity kinematics in healthy, young adults. Fifteen volunteers participated in this study which obtained lower extremity kinematic data on two over-ground walking conditions (barefoot and preferred shoes). Gait velocity, stance width, and stride length, along with sagittal plane hip, knee, and ankle angular positions were computed; hip, knee, and ankle positions were normalized to 100% of the stride. Dependent t-tests were used to compare baseline and shoe conditions for gait velocity and stance width; a two-way analysis of variance was used for stride length. A point-by-point Model Statistic analysis was used to identify significant differences in angular joint positions between conditions. Our results indicate that shoes affected the ankle angular joint position for more than half of the gait cycle, and affected the knee angular joint position, but only for approximately 20% of the cycle. The hip was unaffected by shoes. Gait velocity and stance width were statistically significant, with gait velocity being greater for shoes, and stance width being greater while barefoot. Stride length was not statistically significant between conditions. These outcomes suggest that researchers should use caution if they are considering a barefoot condition as a 'baseline' for healthy, young adults, as there are marked changes in the ankle, and in traditional gait metrics.

Acute effects of footwear on running impact loading in the preschool years

The aim of this study was to assess acute effects of footwear conditions (barefoot, minimalist and standard running shoes) on running impact loading in the preschool years. Fourty-eight habitually shod preschool children (26 males and 22 females) were divided into four age groups (3-, 4-, 5- and 6-year-old). Children performed a simple running game in three different conditions. Three-dimensional biomechanical analysis was carried out during overground running. Statistical parametric mapping was performed on the vertical ground reaction force profiles during the stance phase and one-way repeated measures ANOVA on the vertical instantaneous loading rate. Three-year-old children displayed significantly lower vertical ground reaction force values in the barefoot condition compared to minimalist (3-7% stance) and standard running shoes (7-11% stance). There were also differences in vertical instantaneous loading rate, where 3-year-olds had lower loading when barefoot than in minimalist (p = 0.010, d = 1.19) or running shoes (p = 0.045, d = 0.98), despite no differences in the footstrike pattern (mostly rearfoot-midfoot strike). No differences were found for the older children. Running in minimalist shoes did not imitate barefoot running in 3-year-old children. On the contrary, increased loading was observed in minimalist shoes in early running developmental stages.

The effects of footwear on dynamic stability and impact loading in jump landing

Research into the effect of footwear on dynamic stability and impact loading is still in its infancy. The aim of this study was to determine whether cushioned footwear influenced dynamic stability (dynamic postural stability index (DPSI) and time to stabilisation (TTS)) or impact loading (peak ground reaction force (pGRF) and loading rate (LR)) through a series of single-leg jump landings when compared to barefoot and minimalist shoes. Fourteen healthy, active participants (9 males, 5 females, Age: 21 ± 1 years; height: 174 ± 9.87 cm; weight: 75 ± 15.40 kg) were recruited to undergo a series of single-leg jump landings. Each participant randomly performed three jumps in each footwear condition. Repeated measures ANOVA was conducted to determine whether any differences occurred between condition. No statistically significant difference was observed for DPSI (p = 0.300, pη2 = 0.083) between footwear types. A statistically significant difference was determined between footwear condition for TTS (p = 0.001, pη2 = 0.52), and also for pGRF (p = 0.003, pη2 = 0.39), and LR (p ≤ 0.001, pη2 = 0.53). For TTS, pGRF, and LR, no differences were noted between minimalist and barefoot, but were worse in the cushioned shoe vs. both other conditions. Overall, this study determined that cushioned footwear can negatively influence both TTS and impact loading, but not DPSI.

shod walking during indoor and outdoor conditions in younger and older adults

BACKGROUND

Gait stability and variability measures in barefoot and shod locomotion are frequently investigated in younger but rarely in older adults. Moreover, most studies examine gait measures in laboratory settings instead of real-life settings.

RESEARCH QUESTIONS

How are gait stability and variability parameters affected by footwear compared to barefoot walking in younger and older adults as well as under indoor vs. outdoor conditions?

METHODS

Healthy younger (<35 years) and older adults (>65 years) participated in the randomised within-subject study design. Participants conducted consecutive 25 m walking trials barefoot and with standardised footwear inside and outside. Inertial measurement units were mounted on the participant's foot and used to calculate local dynamic stability (LDS), velocity and minimal toe clearance (MTC), stride length and stride time, including variabilities for these parameters. Linear mixed models were calculated.

RESULTS

Data of 32 younger (17 female, 15 male, age: 30 ± 4 years) and 42 older participants (24 female, 18 male, age: 71 ± 4 years) were analysed. MTC variability was higher in shod conditions compared to barefoot (p = 0.048) and in outdoor conditions (p < 0.001). LDS was different between age groups (p < 0.001). Gait velocity and MTC were higher in shod and outdoor conditions (both p < 0.001). Stride length and time were higher in shod conditions (both p < 0.001) and different between outdoor vs. indoor (longer stride length and shorter stride time outdoor, both (p < 0.001) as well as age groups (shorter stride length (p < 0.021) and stride time in older adults (p < 0.001).

SIGNIFICANCE

Results suggest that gait stability and variability in older and younger adults are acutely affected by footwear vs. barefoot and indoor vs. outdoor walking conditions, indicating a high adaptiveness of these parameters to different experimental conditions. Consequently, future studies should be careful with generalising results obtained under certain conditions. Findings stress the clinical potential of barefoot walking.

Are habitually barefoot children compelled to wear ill-fitting school shoes? A cross-sectional study

Background

Research shows that ill-fitting shoes can negatively impact the development of the pediatric foot, in a very direct manner. The primary aim of the study was to determine if the dimensions of available prescribed school shoes fit the foot dimensions of habitually barefoot South African children and adolescents.

Methods

A cross-sectional observational study was conducted where static standing foot measurements of children and adolescents from urban and rural schools were obtained with a mobile caliper. The maximum heel-toe-length and foot width with an added 10 mm toe- and width fit allowance to each participant, were compared to the corresponding school shoe length and shoe width available in retail. A mixed model ANOVA was used to compare foot dimensions between gender, age and side.

Results

Six hundred and ninety-eight school children (N = 698) (431 girls; 267 boys; average age 10.86 years, SD = 2.55) were participants. A total of seventy-seven (N = 77) black coloured prescribed school shoes currently available in retail ranging from different styles and brands were measured. Results show that, comparing the shoe length and maximum heel-toe-length of participants, as well as taking 10 mm toe allowance into account, fifty-nine percent (59%) of children wore shoes that were not the correct length. With regards to the shoe width and the added 10 mm of width fit allowance, ninety-eight percent (98%) of the shoes worn by participants were too narrow for their feet.

Conclusions

Results confirmed that school shoes currently available in retail, are not suited for the habitually barefoot population studied. It is recommended that the shoe manufacturing industry should consider the shoe width of school shoes for children and adolescents in habitually barefoot populations to avoid the long-term negative effect of ill-fitting shoes on the pediatric foot.

Influence of footwear, foot-strike pattern and step frequency on spatiotemporal parameters and lower-body stiffness in running

This study aimed to determine the influence of footwear condition, foot-strike pattern and step frequency on running spatiotemporal parameters and lower-body stiffness during treadmill running. Thirty-one amateur endurance runners performed a two-session protocol (shod and barefoot). Each session consisted of two trials at 12 km · h^-1 over 5 minutes altering step frequency every minute (150, 160, 170, 180 and 190 spm). First, participants were instructed to land with the heel first; after completion, the same protocol was repeated landing with the forefoot first. Repeated measures ANOVAs showed significant differences for footwear condition, foot-strike pattern and step frequency for each variable: percent contact time, percent flight time, vertical stiffness and leg stiffness (all p < 0.001). The results demonstrate greater estimated vertical and leg stiffness when running barefoot for both foot-strike patterns showing the largest values for barefoot+forefoot condition. Likewise, both vertical and leg stiffness became greater as step frequency increased. The proper manipulation of these variables facilitates our understanding of running performance and assist in training programmes design and injury management.

Impact Acceleration During Prolonged Running While Wearing Conventional Versus Minimalist Shoes

Purpose: In recent years a sub-group of minimalist runners have emerged who aim to perform physical exercise more naturally in an attempt to reduce running-related injuries. Here we aimed to determine the effect that running with minimalist footwear in a prolonged run has on foot-impact accelerations. Method: Seventeen runners ran with minimalist and conventional shoes (MS and CS, respectively) in two separate sessions; the participants had experience with both footwear types. We measured the length and frequency of each stride, as well as the tibial and head impact acceleration every 5 minutes during a prolonged run (30 minutes at 80% of each individual's maximum aerobic speed). Results: There were significant differences in the acceleration rate in the tibia (CS: 516.1 ± 238.47 G/s and MS: 786.6 ± 238.45 G/s; p = .009) and head (CS: 73.3 ± 23.65 G/s and MS: 120.7 ± 44.13 G/s; p = .000). Our data indicate that the type of footwear increased the stride frequency and decreased length and that the impact acceleration is increased with MS compared to CS (p < .05 in both cases). However, the effect of prolonged run was not significantly different between CS and MS (p < .05). Conclusions: The peak tibia acceleration and headtibia acceleration rate indicate that the use of MS may be related to a higher risk of injury. These differences remained independently of the runners' fatigue state.

Long-term effects of school barefoot running program on sprinting biomechanics in children: A case-control study

BACKGROUND

The acute changes of running biomechanics in habitually shod children when running barefoot have been demonstrated. However, the long-term effects of barefoot running on sprinting biomechanics in children is not well understood.

RESEARCH QUESTION

How does four years of participation in a daily school barefoot running program influence sprint biomechanics and stretch-shortening cycle jump ability in children?

METHODS

One hundred and one children from barefoot education school (age, 11.2 ± 0.7 years-old) and 93 children from a control school (age, 11.1 ± 0.7 years-old) performed 50 m maximal shod and barefoot sprints and counter movement jump and five repeated-rebound jumping. To analyse sprint kinematics, a high-speed camera (240 fps) was used. In addition, foot strike patterns were evaluated by using three high-speed cameras (300 fps). Jump heights for both jump types and the contact times for the rebound jump were measured using a contact mat system. Two-way mixed ANOVA was used to examine the effect of school factor (barefoot education school vs control school) and footwear factor (barefoot vs shod) on the sprinting biomechanics.

RESULTS

Sprinting biomechanics in barefoot education school children was characterised by significantly shorter contact times (p = 0.003) and longer flight times (p = 0.005) compared to control school children regardless of footwear condition. In shod sprinting, a greater proportion of barefoot education school children sprinted with a fore-foot or mid-foot strike compared to control school children (p < 0.001). Barefoot education school children also had a significantly higher rebound jump height (p = 0.002) and shorter contact time than control school children (p = 0.001).

SIGNIFICANCE

The results suggest that school-based barefoot running programs may improve aspects of sprint biomechanics and develop the fast stretch-shortening cycle ability in children. In order to confirm this viewpoint, adequately powered randomised controlled trials should be conducted.

Do Metal Shoes Contract Heels?-A Retrospective Study on 114 Horses

Heel contraction is an undesired but common condition in domestic horses. Some authors indicate shoeing as a risk factor. There is a correlation between shoeing and a restriction of heel expansion, but the clinical significance is unknown. This study aimed to evaluate the influence of shoeing and other risk factors, such as age, access to paddock, and breed, on heel contraction. This study included 114 horses, 55 of which were barefoot their whole life and 59 had been shod consistently for at least the previous year. The width and length of the frog were measured. Linear mixed-effects models were performed for the width:length ratio, where the fixed effects were age, sex, breed, pasture or paddock time, shoeing and its duration, and limb. The random effects included the horse and the yard. Although heel contraction occurs more often in shod horses compared with barefoot horses, the difference between the two conditions was not statistically significant, when other factors were considered. The most important factors that impacted contraction were individual horse features and breed (P < .001). The effect of age and a yard was noticed (P < 0,5). The sex, paddock time, and the shoeing and its duration were found not to have statistical significance. The study concluded that heel contraction is multifactorial problem, mainly caused by breed and unknown features correlated with individual. It was not confirmed that horseshoeing causes heel contraction. Because of significant difference in incidence of contraction between yards, there is a need to further investigation of environmental factors causing this hoof distortion.

What is the foot strike pattern distribution in children and adolescents during running? A cross-sectional study

BACKGROUND

There is a lack of studies describing foot strike patterns in children and adolescents. This raises the question on what the natural foot strike pattern with less extrinsic influence should be and whether or not it is valid to make assumptions on adults based on the knowledge from children.

OBJECTIVES

To investigate the distribution of foot strike patterns in children and adolescents during running, and the association of participants' characteristics with the foot strike patterns.

METHODS

This is a cross-sectional study. Videos were acquired with a high-speed camera and running speed was measured with a stopwatch. Bayesian analyses were performed to allow foot strike pattern inferences from the sample to the population distribution and a supervised machine learning procedure was implemented to develop an algorithm based on logistic mixed models aimed at classifying the participants in rearfoot, midfoot, or forefoot strike patterns.

RESULTS

We have included 415 children and adolescents. The distribution of foot strike patterns was predominantly rearfoot for shod and barefoot assessments. Running condition (barefoot versus shod), speed, and footwear (with versus without heel elevation) seemed to influence the foot strike pattern. Those running shod were more likely to present rearfoot pattern compared to barefoot. The classification accuracy of the final algorithm ranged from 80% to 88%.

CONCLUSIONS

The rearfoot pattern was predominant in our sample. Future well-designed prospective studies are needed to understand the influence of foot strike patterns on the incidence and prevalence of running-related injuries in children and adolescents during running, and in adult runners.

A comparison of young children's spatiotemporal measures of walking and running in three common types of footwear compared to bare feet

BACKGROUND

Clinicians and footwear manufacturers often advise young children to wear soft-soled footwear when they are first learning to walk. There is limited evidence as to why this advice is given, and if soft-soled shoes are as close to barefoot as thought.

RESEARCH QUESTION

What are the differences in spatiotemporal measures of gait during walking and running in three common types of children's footwear with a soft-soled compared to barefoot in young children?

METHODS

The study used a quasi-experimental design, with the condition order randomised using a Latin square sequence. Forty-seven children were recruited (2 - 4 years). Participants walked or ran the length of a GAITrite mat in a randomized order for barefoot and soft-soled sneaker, boot and sandal conditions. Linear regression analyses were used to investigate the main effect of each soft-soled footwear compared to bare feet in the different gait parameters.

RESULTS

For walking and running trials, cadence decreased whereas step time and stride length increased in all footwear types compared to the barefoot condition. While wearing sneakers and sandals increased the stance percentage for walking and running trials, compared to barefoot, this difference was only apparent during the running trial for the boots. Likewise, although double support time increased for both the boots and sneakers in walking and running, compared to barefoot, this difference was only observed in the sandals during walking.

SIGNIFICANCE

This research found that various types of soft-soled footwear impacted gait compared to the barefoot condition, with some differences seen between walking and running trials. These findings challenge the assumption that soft-soled footwear facilitate a similar gait to barefoot walking and running, although the clinical significance of these differences is unknown.

with minimalist footwear - influence on gait in younger and older adults

Background

In recent years, minimalist footwear has been increasingly promoted for its use in sportive and recreational activities. These shoes are considered to function naturally like barefoot walking while providing a protective surface. Despite a growing popularity of these shoes in the older population, little is known about the influence of minimalist footwear on gait patterns. This study investigated whether overground walking with minimalist shoes is comparable to barefoot walking regarding gait stability and variability parameters.

Methods

In a randomized within-subject study design, 31 healthy younger (29 ± 4 years) and 33 healthy community-dwelling older adults (71 ± 4 years) volunteered. Participants walked on flat ground, once barefoot and once with minimalist shoes. Gait variability of minimum toe clearance (MTC), stride length, stride time, and local dynamic gait stability were analysed.

Results

The results for both age groups showed significant condition effects (minimalist shoes vs. barefoot walking) for the outcomes of local dynamic stability (p = .013), MTC variability (p = .018), and stride length variability (p < .001) indicating increased local dynamic stability and decreased gait variability during the minimalist shoe condition. Group effects (young vs. older adults) were detected in all gait outcomes.

Conclusion

Walking with minimalist shoes appeared to be associated with better gait performance than walking barefoot in both age groups. Thus, walking with minimalist shoes is not similar to barefoot walking. With respect to reducing the risk of falling, we suggest that minimalist shoes could be an alternative to barefoot walking or a transition option between shoes to barefoot for older adults.

Factors associated with type of footwear worn inside the house: a cross-sectional study

Background

In specific populations, including those at risk of falls or foot ulcers, indoor footwear is an important aspect of preventative care. This study aims to describe the indoor footwear worn most over the previous year in a sample representative of the Australian inpatient population, and to explore the sociodemographic, medical, foot condition and foot treatment history factors associated with the indoor footwear worn.

Methods

This was a secondary analysis of data collected from inpatients admitted to five hospitals across Queensland, Australia. Sociodemographic information, medical history, foot conditions and foot treatment history were collected as explanatory variables. Outcomes included the self-reported type of indoor footwear (from 16 standard footwear types) worn most in the year prior to hospitalisation, and the category in which the self-reported footwear type was defined according to its features: 'protective', 'non-protective' and 'no footwear'. Multivariate analyses determined explanatory variables independently associated with each type and category.

Results

Protective footwear was worn by 11% of participants (including 4% walking shoes, 4% running shoes, 2% oxford shoes), and was independently associated with education above year 10 level (OR 1.78, p = 0.028) and having had foot treatment by a specialist physician (5.06, p = 0.003). Most participants (55%) wore non-protective footwear (including 21% slippers, 15% thongs/flip flops, 7% backless slippers), which was associated with older age (1.03, p < 0.001). No footwear was worn by 34% of participants (30% barefoot, 3% socks only). Those of older age (0.97, p < 0.001) and those in the most disadvantaged socioeconomic group (0.55, p = 0.019) were less likely to wear no footwear (socks or barefoot).

Conclusions

Only one in nine people in a large representative inpatient population wore a protective indoor footwear most of the time in the previous year. Whilst having education levels above year 10 and having received previous foot treatment by a specialist physician were associated with wearing protective footwear indoors, the presence of a range of other medical and foot conditions were not. These findings provide information to enable clinicians, researchers and policymakers to develop interventions aimed at improving indoor footwear habits that may help prevent significant health burdens such as falls and foot ulcers.

Accuracy and repeatability of a semi-quantitative barefoot pressure measurement method for clinical use: The Derks Calculation Method

BACKGROUND

This study was designed to assess the accuracy and repeatability of the Derks Calculation Method in the normal foot during walking.

METHODS

Measurements were taken from 25 healthy subjects (age 32.0 ± 12.4), 23 females and 2 males, on five separate occasions at seven days, three weeks, three months, and nine months apart by means of a mid-gait method. Values were calculated for internal rotation (IR) and external rotation of the heel (ER), heel valgus/varus (HV), heel length (HL), heel width (HW), width of the midfoot (WM) and the forefoot (WF), and the length of the foot (LF).

RESULTS

For all five separate occasions and in 87.5% of the parameters investigated, the coefficient of repeatability (CR, expressed as a percentage of the mean) was less than 5%. One parameter showed a high CR - heel valgus/varus (HV) was extremely high (>800%). The maximum 95% Confidence Interval (CI) for the five different occasions was no higher than 0.2 cm for IR, ER and HV with a standard error (SE) of 0.01 and >0.01 respectively. The maximum 95% CI for WF was 0.4 cm (SE 0.1), and for HW, WM and LF the maximum 95% CI was 0.7 cm (SE 0.1 or 0.2). HL showed the highest 95% CI (0.9 cm) with an SE of 0.2.

CONCLUSION

The Derks Calculation Method was found to be accurate and repeatable if HV was excluded, which renders this method a viable clinical tool in settings where sophisticated computerised systems are still unavailable.

The effects of habitual footwear in gait outcomes in people with Parkinson's disease

BACKGROUND

Gait is impaired in individuals with Parkinson's disease (PD). Although the effect of habitual footwear on gait spatiotemporal parameters has already been established in neurologically healthy individuals, its effects on people with PD is unknown.

RESEARCH QUESTION

This study aimed to investigate the impact of habitual footwear on the step spatiotemporal parameters in people with PD.

METHODS

Sixteen individuals with PD (G-PD) and 15 neurologically healthy individuals (G-HC) were assessed. Participants walked on an 8 m long pressure sensitive walkway at their preferred speed with and without their habitual footwear (3 trials per condition). Footwear included flip-flops, shoes, sneakers and sandals. The average, variability and asymmetry for step length, width, duration, and velocity and the percentage time in the swing and stance phases were calculated.

RESULTS

The results showed in both groups a reduced percentage time in the swing phase and an increased step width, duration and length with footwear (F(1,29)>5.64; p<0.02). Additionally, habitual footwear increased step width variability in G-PD and G-HC (F(1,29)=3.97; p=0.06). Interestingly, only G-HC showed a higher step length asymmetry in the footwear condition than in the barefoot condition (p=0.02). Finally, only when habitual footwear was used, G-HC showed a higher step velocity asymmetry than G-PD (p=0.04).

SIGNIFICANCE

These results indicate a negative influence of footwear on gait spatiotemporal parameters in both groups. Furthermore, footwear induced differences between groups. These findings indicate that footwear use is an influencing factor in studies comparing people with PD and healthy elderly. Further data are needed before definitive recommendations are made.

The balance control of young children under different shod conditions in a naturalistic environment

BACKGROUND

A primary function of footwear is to protect the feet from environmental conditions and possibly, to reduce the risk of injury. In addition, the use of footwear may be critical to improve the balance control of young children at their early years. Therefore, the objective of this study was to evaluate the performance of different balance tasks in young children under barefoot (unshod) and own covered footwear (shod) conditions.

RESEARCH QUESTION

Does footwear affect the balance control of young children?

METHODS

Twenty-three young children (n = 23, M age = 6.32 ± 0.27 years, age range: 5-6 years) participated in this study. Three balance tasks, 1) One-leg stand, 2) Walking heels raised and 3) Jumping on mats were used to determine the balance proficiency of young children.

RESULTS

The mean scores of the young children were significantly higher with a lower standard deviation under shod condition for the task of walking heels raised.

SIGNIFICANCE

These results suggest that own covered footwear could aid in providing increased postural stability for complex and novel balance tasks which are highly unstable.

Effects of barefoot and footwear conditions on learning of a dynamic balance task: a randomized controlled study

PURPOSE

Although barefoot balancing has shown to be more challenging compared to shod balancing, it is still unclear whether this may also influence the balance learning effects. The purpose of this study was to explore the impact of barefoot and shod exercising on learning of a dynamic balance task.

METHODS

Sixty healthy and physically active adults (mean age 25.3 ± 3.4 years) were randomly allocated into one of three groups (barefoot, shod and controls). The barefoot and shod intervention groups exercised once weekly over 7 weeks on a stability platform with an unstable surface. Each training session included 15 trials over 30 s. Before and after the intervention period, all participants completed two balance tests (stability platform and Balance Error Scoring System = BESS) under barefoot and shod conditions. Group effects in stability gains (pre to post-test differences) were analysed using ANOVA. Development of balance learning curves during the intervention period was analysed using a mixed effects model.

RESULTS

Balance times improved in both intervention groups (p < 0.001, 95% CI barefoot 5.82-9.22 s, shod 7.51-10.92 s) compared to controls. The barefoot intervention group showed a significantly less sloped balance learning curve compared to the shod intervention group (p = 0.033). No changes over time or differences between groups were found for the BESS test.

CONCLUSIONS

Improvements in the dynamic balance task did not differ between individuals exercising barefoot or with footwear although the progression was slower in the barefoot group. The lack of changes in the BESS supports the task-specificity of balance learning effects.

Effects of wearing shoes on the feet: Radiographic comparison of middle-aged partially shod Maasai women's feet and regularly shod Maasai and Korean women's feet

BACKGROUND

Maasai tribe members walk long distances daily either barefoot or wearing traditional shoes made from recycled car tires, without any foot ailments. To figure out the characteristic of their feet, we designed a radiographic comparative study of middle-aged partially shod Maasai women's feet and regularly shod Maasai and Korean women's feet.

METHODS

Weight bearing radiographs of bilateral foot and ankle joints from 20 healthy middle-aged bush-living partially shod (PS) Maasai women were obtained. Same number of radiographs from 20 urban-living regularly shod (RS) Maasai and 20 Korean women were obtained and compared. The hallux valgus angle, the first to second intermetatarsal angle, talonavicular coverage angle, talo-first metatarsal angle, Meary angle, naviculo-cuboidal overlap, and the medial cuneiform height were measured to establish the degree of pes plano-valgus and hallux valgus deformity.

RESULTS

On comparing PS and RS Maasai groups radiographically, the talonavicular coverage angle, talo-first metatarsal angle, and naviculo-cuboidal overlap were significantly greater in the PS Maasai group, whereas hallux valgus angle, the first and second intermetatarsal angle, Meary angle, and the medial cuneiform height were greater in the RS Maasai and Korean group.

CONCLUSIONS

Regularly wearing shoes would protect the feet from pes plano-valgus deformity, despite potentially contributing to hallux valgus deformity.

Prevalence at home, in school and during sport: a cross-sectional survey of 714 New Zealand secondary school boys

Background

It may be assumed that a combination of culture, climate and economic resource are the major reasons that non-industrialised countries have a higher prevalence of barefoot activity. New Zealand is an industrialised country with comparable resources to that of many European countries; however, it seems to remain socially acceptable to carry out barefoot activities. A chance observation of students competing barefoot on a tartan track, prompted us to determine the prevalence of barefoot activity in an all-boys secondary school in Auckland New Zealand.

Method

An 11-question survey was administered at an Auckland boys secondary school, of high socioeconomic status, to determine the footwear habits of students (n = 714) during: a) daily life b) school life (c) physical education class and (d) sport. To classify students as habitually barefoot or shod, students were asked to select whether they were barefoot most of the time (2-points), half of the time (1-point) or none of the time (0-points) in three settings: around the house, during sport and during school. A score of ≥3 was required to be considered habitually barefoot. Participants were also asked to specify, when running at their most recent athletics event (100 m – 3000 m) on a track, whether they ran barefoot, in shoes, in spikes or another type of footwear. Finally, participants were asked to indicate if leg pain had interrupted running during the previous 12-months. Analysis was conducted using IBM SPSS.

Results

45% (95% CI: 41.5–49.5%) of the participants in our sample were classified as habitually barefoot. More than half of the sample reported being barefoot most of the time at home (n = 404, 56.6%) and during PE class (n = 420, 58.8%). Over 50% of the sample reported being barefoot half of the time or more during sport (n = 380, 53.2%). A smaller amount went to the supermarket (n = 140, 19.6%) or took the bus (n = 59, 8.3%) whilst barefoot around half of the time or more. The percentage of barefoot competitors declined with increasing distance: 100 m (46.5%), 200 m (41.8%), 400 m (38%), 800 m (31%), 1500 m (31%) and 3000 m (20%). The prevalence of leg pain interfering with running was 23.5%. There was no difference in the prevalence of leg pain between those classified as habitually barefoot and shod (Χ²(1, N = 603) = 0.005, p = 0.946).

Conclusion

The results of this survey demonstrate that over 50% of students at an all-boys secondary school in Auckland, of high socioeconomic status, are barefoot at home, during physical education and sport half of the time or more. These results may point towards a cultural difference between New Zealand and other modern industrialised countries.

Is symmetry of loading improved for injured runners during novice barefoot running?

BACKGROUND

As barefoot (BF) running provides important sensory information that influence landing patterns, it may also affect loading symmetry.

RESEARCH QUESTION

The purpose of this investigation was to examine whether symmetry of loading in a group of injured runners would be improved in a novice, barefoot condition.

METHODS

Cross-sectional design evaluating 67 injured RFS runners. Each subject ran on an instrumented treadmill, first with their habitual shod pattern and then in a BF condition with a FFS pattern, both at the same self-selected speed. Data were averaged over 10 footstrikes. Variables of interest included vertical average load rate, vertical instantaneous load rate, and resultant instantaneous load rate. Symmetry indices (SI) for full population and within quartiles were compared for each loadrate variable (P ≤ 0.05) to evaluate changes between conditions.

RESULTS

On average, symmetry of loading was similar in a novice BF condition of injured runners compared with their habitual RFS shod condition. However, a subanalysis of quartiles revealed that the injured runners with the highest asymmetry (greatest SI values) displayed significantly lower asymmetry when running BF for all three loadrate measures.

SIGNIFICANCE

The addition of sensory input during barefoot running only improves symmetry of loading when habitual loading is highly asymmetric.

Barefoot running does not affect simple reaction time: an exploratory study

Background

Converging evidence comparing barefoot (BF) and shod (SH) running highlights differences in foot-strike patterns and somatosensory feedback, among others. Anecdotal evidence from SH runners attempting BF running suggests a greater attentional demand may be experienced during BF running. However, little work to date has examined whether there is an attentional cost of BF versus SH running.

Objective

This exploratory study aimed to examine whether an acute bout of BF running would impact simple reaction time (SRT) compared to SH running, in a sample of runners naïve to BF running.

Methods

Eight male distance runners completed SRT testing during 10 min of BF or SH treadmill running at 70% maximal aerobic speed (17.9 ± 1.4 km h⁻¹). To test SRT, participants were required to press a hand-held button in response to the flash of a light bulb placed in the center of their visual field. SRT was tested at 1-minute intervals during running. BF and SH conditions were completed in a pseudo-randomized and counterbalanced crossover fashion. SRT was defined as the time elapsed between the light bulb flash and the button press. SRT errors were also recorded and were defined as the number of trials in which a button press was not recorded in response to the light bulb flash.

Results

Overall, SRT later in the exercise bouts showed a statistically significant increase compared to earlier (p < 0.05). Statistically significant increases in SRT were present at 7 min versus 5 min (0.29 ± 0.02 s vs. 0.27 ± 0.02 s, p < 0.05) and at 9 min versus 2 min (0.29 ± 0.03 s vs. 0.27 ± 0.03 s, p < 0.05). However, BF running did not influence this increase in SRT (p > 0.05) or the number of SRT errors (17.6 ± 6.6 trials vs. 17.0 ± 13.0 trials, p > 0.05).

Discussion

In a sample of distance runners naïve to BF running, there was no statistically significant difference in SRT or SRT errors during acute bouts of BF and SH running. We interpret these results to mean that BF running does not have a greater attentional cost compared to SH running during a SRT task throughout treadmill running. Literature suggests that stride-to-stride gait modulation during running may occur predominately via mechanisms that preclude conscious perception, thus potentially attenuating effects of increased somatosensory feedback experienced during BF running. Future research should explore the present experimental paradigm in a larger sample using over-ground running trials, as well as employing different tests of attention.

Modifications in lower leg muscle activation when walking barefoot or in minimalist shoes across different age-groups

Ageing is associated with a decline in muscle strength and impaired sensory mechanisms which contribute to an increased risk of falls. Walking barefooted has been suggested to promote increased muscle strength and improved proprioceptive sensibility through better activation of foot and ankle musculature. Minimalist footwear has been marketed as a method of reaping the suggested benefits of barefoot walking whilst still providing a protective surface. The aim of this study was to investigate if walking barefoot or in minimalist footwear provokes increased muscle activation compared to walking in conventional footwear. Seventy healthy adults (age range 20-87) volunteered for this study. All participants walked along a 7m walking lane five times in four different footwear conditions (barefoot (BF), minimalist shoes (MSH), their own shoes (SH) and control shoes (CON)). Muscle activity of their tibialis anterior (TA), gastrocnemius medialis (GCM) and peroneus longus (PL) were recorded simultaneously and normalised to the BF condition. MSH are intermediate in terms of ankle kinematics and muscle activation patterns. Walking BF or in MSH results in a decrease in TA activity at initial stance due to a flatter foot at contact in comparison to conventional footwear. Walking BF reduces PL activity at initial stance in the young and middle age but not the old. Walking in supportive footwear appears to reduce the balance modulation role of the GCM in the young and middle age but not the old, possibly as a result of slower walking speed when BF.

Foot strike pattern in children during shod-unshod running

The purpose of this study was to determine the foot strike patterns (FSPs) and neutral support (no INV/EVE and no foot rotation) in children, as well as to determine the influence of shod/unshod conditions and sex. A total of 713 children, aged 6 to 16 years, participated in this study (Age=10.28±2.71years, body mass index [BMI]=19.70±3.91kg/m², 302 girls and 411 boys). A sagittal and frontal-plane video (240Hz) was recorded using a high-speed camcorder, to record the following variables: rearfoot strike (RFS), midfoot strike (MFS), forefoot strike (FFS), inversion/eversion (INV/EVE) and foot rotation on initial contact. RFS prevalence was similar between boys and girls in both shod and unshod conditions. In the unshod condition there was a significant reduction (p<0.001) of RFS prevalence both in boys (shod condition=83.95% vs. 62.65% unshod condition) and in girls (shod condition=87.85% vs. 62.70% unshod condition). No significant differences were found in INV/EVE and foot rotation between sex groups. In the unshod condition there was a significant increase (p<0.001) of neutral support (no INV/EVE) both in boys (shod condition=12.55% vs. 22.22% unshod condition) and in girls (shod condition=17.9% vs. 28.15% unshod condition). In addition, in the unshod condition there is a significant reduction (p<0.001) of neutral support (no foot rotation) both in boys (shod condition=21.55% vs. 11.10% unshod condition) and in girls (shod condition=21.05% vs. 11.95% unshod condition). In children, RFS prevalence is lower than adult's population. Additionally, barefoot running reduced the prevalence of RFS and INV/EVE, however increased foot rotation.

Superficial plantar cutaneous sensation does not trigger barefoot running adaptations

It has long been proposed that the gait alterations associated with barefoot running are mediated by alterations in sensory feedback, yet there has been no data to support this claim. Thus, the purpose of this study was to examine the role of superficial plantar cutaneous feedback in barefoot and shod running.

METHODS

10 healthy active subjects (6 male, 4 female); mass: 65.2+9.7kg; age: 27+7.1years participated in this study. 10 over-ground running trials were completed in each of the following conditions: barefoot (BF), shod (SHOD), anesthetized barefoot (ANEST BF) and anesthetized shod (ANEST SHOD). For the anesthetized conditions 0.1-0.3mL of 1% lidocaine was injected into the dermal layer of the plantar foot below the metatarsal heads, lateral column and heel. 3-dimensional motion analysis and ground reaction force (GRF) data were captured as subjects ran over a 20m runway with a force plate at 12m. Kinematic and kinetic differences were analyzed via two-way repeated measure ANOVAs.

RESULTS

The differences in gait between the BF and SHOD conditions were consistent with previous research, with subjects exhibiting a significant decrease in stride length and changing from rearfoot strike when SHOD to fore/midfoot strike when BF. Additionally, BF running was associated with decreased impact peak magnitudes and peak vertical GRFs. Despite anesthetizing the plantar surface, there was no difference between the BF and ANEST BF conditions in terms of stride length, foot strike or GRFs.

CONCLUSION

Superficial cutaneous sensory receptors are not primarily responsible for the gait changes associated with barefoot running.

Spatial and temporal gait characteristics of elderly individuals during backward and forward walking with shoes and barefoot

Backward walking (BW) is an inherent component of mobility and function in daily activities, particularly indoors, when it is more likely that a person is barefoot. No studies to date have compared the spatio-temporal characteristics of BW with and without shoes in elderly individuals. This study compared spatio-temporal measures of BW and forward walking (FW) among elderly individuals while barefoot or wearing shoes. Forty-seven elderly individuals (13 men and 34 women, 76.7±7.7years of age) were evaluated. Participants were requested to walk at a comfortable, self-selected pace across the GAITRite^® walkway for three trials under each of four conditions: walking forward (FW) and BW wearing their own comfortable low-heeled walking shoes and FW and BW walking without shoes. Gait speed, stride length and cadence were significantly reduced in BW versus FW, with an increase in double limb support (DLS), both with and without shoes. Barefoot BW resulted in significantly increased gait speed and cadence, and decreased DLS compared to BW with shoes. BW stride length was not affected by footwear. While barefoot FW was also associated with a significant increase in cadence and decrease in DLS time compared to walking with shoes, it decreased stride length and had no detrimental effect on gait speed. Assessment of the spatio-temporal parameters of walking barefoot and with shoes during FW and BW can contribute to our understanding of the ability of elderly individuals to adapt to changing walking conditions, and should be included in the assessment of functional mobility of elderly individuals.

Effects of load carriage and footwear on lower extremity kinetics and kinematics during overground walking

Kinetic and kinematic responses during walking vary by footwear condition. Load carriage also influences gait patterns, but it is unclear how an external load influences barefoot walking. Twelve healthy adults (5 women, 7 men) with no known gait abnormalities participated in this study (age=23±3years, height=1.73±0.11m, and mass=70.90±12.67kg). Ground reaction forces and 3D motion were simultaneously collected during overground walking at 1.5ms^-1 in four conditions: Barefoot Unloaded, Shod Unloaded, Barefoot Loaded, and Shod Loaded. Barefoot walking reduced knee and hip joint ranges of motion, as well as stride length, stance time, swing time, and double support time. Load carriage increased stance and double support times. The 15% body weight load increased GRFs ∼15%. Walking barefoot reduced peak anteroposterior GRFs but not peak vertical GRFs. Load carriage increased hip, knee, and ankle joint moments and powers, while walking barefoot increased knee and hip moments and powers. Thus, spatiotemporal and kinematic adjustments to walking barefoot decrease GRFs but increase knee and hip kinetic measures during overground walking. The ankle seems to be less affected by these footwear conditions. Regardless of footwear, loading requires larger GRFs, joint loads, and joint powers.

The effect of the kindergarten barefoot policy on preschool children's toes

Background

This study compared the effects of barefoot policy, a policy instructing preschool children to go without shoes, on untouched-toes, which do not touch the ground while standing normally, of preschool children attending kindergartens that follow this rule, to preschooler in kindergartens where they must wear shoes, i.e., no-barefoot policy.

Methods

The study used longitudinal data from measurements taken 2 years apart of the amount of times. The subjects were 59 children (34 boys and 25 girls) who went to a kindergarten that followed barefoot policy and 179 children (103 boys and 76 girls) who went to a kindergarten that did not follow barefoot policy. Images were taken of the contact surface area of the soles of the children’s feet by having them stand on the measurement device with their bare feet.

Results

The number of untouched-toes in children participating in the study was determined from the pictures. In boys who attended kindergartens following barefoot policy, the ratio of the children without untouched-toes significantly increased for 2 years of childhood (35.3–64.7 %). The number of untouched-toes were significantly fewer in boys from kindergartens following barefoot policy than in boys from kindergartens not following the policy, and the magnitude of the difference grew for the two study years (ES: 0.41–0.63). In girls, there were no significant differences between the two groups in the ratio of girls without untouched-toes and the number of untouched-toes.

Conclusions

In conclusion, the ground contact of the toes becomes better for boys in kindergarten with a barefoot policy. The results were inconclusive with regard to girls, and other factors may need to be examined. In the future, it will be necessary to increase the number of the subjects and perform detailed examinations.

Does "transition shoe" promote an intermediate biomechanical condition compared to running in conventional shoe and in reduced protection condition?

This study evaluated if running in a "transition shoe" commercially available results in intermediate mechanical load upon lower extremities compared to conventional shoe and minimalist shoe/barefoot. Kinematic and kinetic parameters while running in different shoe conditions were compared. Fourteen runners (12 men, 2 women; age=28.4±7.3 years), inexperienced in minimalist shoes and barefoot running, ran on an instrumented treadmill within four experimental conditions (conventional shoe - CS, transition shoe - TrS, minimalist shoe - MS, and barefoot - BF). Running was performed at 9km/h for 10min in each experimental condition. Vertical ground reaction force (VGRF) and two-dimensional kinematic variables of lower limbs (both legs) were recorded. Nine data acquisitions (10s) were conducted for each footwear condition. Transition shoe lead to significant changes in VGRF variables related to impact control, while kinematic parameters were little affected. The TrS had smaller first peak of VGRF (Fy1) than CS (p≤0.001) and higher than MS (p=0.050) and BF (p≤0.001). Time to first peak of VGRF (tFy1) of TrS was smaller than CS (p≤0.001) and higher than MS (p≤0.001) and BF (p≤0.001). The TrS and MS induced to lesser knee flexion (p<0.001) and greater dorsiflexion (p<0.001) than CS and BF. Thus, results suggest the transition shoe (TrS) tested seem to promote an intermediate mechanical load condition only for VGRF parameters, presenting values of impact forces between those found for conventional shoe and minimalist shoe/barefoot. Such knowledge could be useful for the transition process from conventional running shoe to minimalist shoe/barefoot.

Normative rearfoot motion during barefoot and shod walking using biplane fluoroscopy

PURPOSE

The ankle rearfoot complex consists of the ankle and subtalar joints. This is an observational study on two test conditions of the rearfoot complex. Using high-speed biplane fluoroscopy, we present a method to measure rearfoot kinematics during normal gait and compare rearfoot kinematics between barefoot and shod gait.

METHODS

Six male subjects completed a walking trial while biplane fluoroscopy images were acquired during stance phase. Bone models of the calcaneus and tibia were reconstructed from computed tomography images and aligned with the biplane fluoroscopy images. An optimization algorithm was used to determine the three-dimensional position of the bones and calculate rearfoot kinematics.

RESULTS

Peak plantarflexion was higher (barefoot: 9.1°; 95% CI 5.2:13.0; shod: 5.7°; 95% CI 3.6:7.8; p = 0.015) and neutral plantar/dorsiflexion occurred later in the stance phase (barefoot: 31.1%; 95% CI 23.6:38.6; shod: 17.7%; 95% CI 14.4:21.0; p = 0.019) during barefoot walking compared to shod walking. An eversion peak of 8.7° (95% CI 1.9:15.5) occurred at 27.8% (95% CI 18.4:37.2) of stance during barefoot walking, while during shod walking a brief inversion to 1.2° (95% CI -2.1:4.5; p = 0.021) occurred earlier (11.5% of stance; 95% CI 0.2:22.8; p = 0.008) during stance phase. The tibia was internally rotated relative to the calcaneus throughout stance phase in both conditions (barefoot: 5.1° (95% CI -1.4:11.6); shod: 3.6° (95% CI -0.4:7.6); ns.).

CONCLUSIONS

Biplane fluoroscopy can allow for detailed quantification of dynamic in vivo ankle kinematics during barefoot and shod walking conditions. This methodology could be used in the future to study hindfoot pathology after trauma, for congenital disease and after sports injuries such as instability.

LEVEL OF EVIDENCE

II.

A comparative study of the feet of middle-aged women in Korea and the Maasai tribe

Background

Members of the Maasai tribe spend their days either barefoot or wearing traditional shoes made from recycled car tires. Although they walk long distances (up to 60 km) daily, they do not generally experience foot ailments. Here, we compared parameters associated with the feet, ankles, and gait of middle-aged women in Korea and the Maasai tribe.

Methods

Foot length, calf circumference, hindfoot alignment, step length, cadence, and walking velocity were compared among 20 middle-aged Korean and bush-living Maasai women. Static and dynamic Harris mat footprints were taken to determine the distribution of forefoot pressure patterns during walking. We also compared several radiographic parameters with standing foot and ankle radiographs.

Results

The mean foot length and width were significantly longer in Maasai women. Interestingly, 38 ft (96 %) in the Maasai group showed a claw deformity of the toe (s). There were no statistically significant differences in gait-related indices and Harris mat findings between the two groups. On radiographic analysis, tibial anterior surface angle, tibial lateral surface angle, talonavicular coverage angle, talo-first metatarsal angle, Meary angle, and naviculo-cuboidal overlap were significantly greater in the Maasai group, whereas hallux valgus angle and the first and second intermetatarsal angle were greater in the Korean group.

Conclusions

Middle-aged women from the Maasai tribe showed a higher prevalence of abducted forefeet, everted hindfeet, and fallen medial longitudinal arches than did Korean women, while Korean women showed a higher prevalence of hallux valgus, a preserved medial longitudinal arch, and toes that are free from claw deformity.

Modelling of Muscle Force Distributions During Barefoot and Shod Running

Research interest in barefoot running has expanded considerably in recent years, based around the notion that running without shoes is associated with a reduced incidence of chronic injuries. The aim of the current investigation was to examine the differences in the forces produced by different skeletal muscles during barefoot and shod running. Fifteen male participants ran at 4.0 m·s-1 (± 5%). Kinematics were measured using an eight camera motion analysis system alongside ground reaction force parameters. Differences in sagittal plane kinematics and muscle forces between footwear conditions were examined using repeated measures or Freidman’s ANOVA. The kinematic analysis showed that the shod condition was associated with significantly more hip flexion, whilst barefoot running was linked with significantly more flexion at the knee and plantarflexion at the ankle. The examination of muscle kinetics indicated that peak forces from Rectus femoris, Vastus medialis, Vastus lateralis, Tibialis anterior were significantly larger in the shod condition whereas Gastrocnemius forces were significantly larger during barefoot running. These observations provide further insight into the mechanical alterations that runners make when running without shoes. Such findings may also deliver important information to runners regarding their susceptibility to chronic injuries in different footwear conditions.

middle-aged adult barefoot gait

The aim of this study was to investigate the effect of flooring on barefoot gait according to age and gender. Two groups of healthy subjects were analyzed: the elderly adult group (EA; 10 healthy subjects) and the middle-aged group (MA; 10 healthy subjects). Each participant was asked to walk at his or her preferred speed over two force plates on the following surfaces: 1) homogeneous vinyl (HOV), 2) carpet, 3) heterogeneous vinyl (HTV) and 4) mixed (in which the first half of the pathway was covered by HOV and the second by HTV). Two force plates (Kistler 9286BA) embedded in the data collection room floor measured the ground reaction forces and friction. The required coefficient of friction (RCOF) was analyzed. For the statistical analysis, a linear mixed-effects model for repeated measures was performed. During barefoot gait, there were differences in the RCOF among the flooring types during the heel contact and toe-off phases. Due to better plantar proprioception during barefoot gait, the EA and MA subjects were able to distinguish differences among the flooring types. Moreover, when the EA were compared with the MA subjects, differences could be observed in the RCOF during the toe-off phase, and gender differences in the RCOF could also be observed during the heel contact phase in barefoot gait.

Barefoot vs common footwear: A systematic review of the kinematic, kinetic and muscle activity differences during walking

Habitual footwear use has been reported to influence foot structure with an acute exposure being shown to alter foot position and mechanics. The foot is highly specialised thus these changes in structure/position could influence functionality. This review aims to investigate the effect of footwear on gait, specifically focussing on studies that have assessed kinematics, kinetics and muscle activity between walking barefoot and in common footwear. In line with PRISMA and published guidelines, a literature search was completed across six databases comprising Medline, EMBASE, Scopus, AMED, Cochrane Library and Web of Science. Fifteen of 466 articles met the predetermined inclusion criteria and were included in the review. All articles were assessed for methodological quality using a modified assessment tool based on the STROBE statement for reporting observational studies and the CASP appraisal tool. Walking barefoot enables increased forefoot spreading under load and habitual barefoot walkers have anatomically wider feet. Spatial-temporal differences including, reduced step/stride length and increased cadence, are observed when barefoot. Flatter foot placement, increased knee flexion and a reduced peak vertical ground reaction force at initial contact are also reported. Habitual barefoot walkers exhibit lower peak plantar pressures and pressure impulses, whereas peak plantar pressures are increased in the habitually shod wearer walking barefoot. Footwear particularly affects the kinematics and kinetics of gait acutely and chronically. Little research has been completed in older age populations (50+ years) and thus further research is required to better understand the effect of footwear on walking across the lifespan.

Effects of load carriage and footwear on spatiotemporal parameters, kinematics, and metabolic cost of walking

Gait patterns are commonly altered when walking or running barefoot compared to shod conditions. Although controversy exists as to whether barefoot conditions result in lower metabolic costs, it is clear that adding load to the body results in increased metabolic costs. The effects of footwear and backpack loading have been investigated separately, but it is unclear whether manipulating both simultaneously would cause similar outcomes. Twelve healthy individuals (7 female, 5 male) with no obvious gait abnormalities participated in this study (age=24±2 years, height=1.73±0.13 m, and mass=71.1±16.9 kg). Steady state metabolic data and 3D motion capture were collected during treadmill walking at 1.5 ms(-1) in four conditions: Barefoot Unloaded, Shod Unloaded, Barefoot Loaded, and Shod Loaded. Barefoot walking elicited shorter stride lengths, stance and double support times, as well as a slight (≈1%), but not significant, decrease in metabolic cost. Loading increased metabolic costs of walking but did not elicit spatiotemporal changes in either footwear condition. Lower limb kinematic differences were noted in response to both loading and footwear. Changes in spatiotemporal parameters observed when walking barefoot were not exacerbated by the addition of a backpack load. This suggests that the increased metabolic demand associated with the load is met with a similar spatiotemporal pattern whether a person wears a supportive shoe or not. Thus, the discomfort associated with foot strike while barefoot that promotes spatiotemporal changes seems to be independent of load.

Plantar loading and foot-strike pattern changes with speed during barefoot running in those with a natural rearfoot strike pattern while shod

BACKGROUND

Claims of injury reduction related to barefoot running has resulted in interest from the running public; however, its risks are not well understood for those who typically wear cushioned footwear.

OBJECTIVES

Examine how plantar loading changes during barefoot running in a group of runners that ordinarily wear cushioned footwear and demonstrate a rearfoot strike pattern (RFSP) without cueing or feedback alter their foot strike pattern and plantar loading when asked to run barefoot at different speeds down a runway.

METHOD

Forty-one subjects ran barefoot at three different speeds across a pedography platform which collected plantar loading variables for 10 regions of the foot; data were analyzed using two-way mixed multivariate analysis of variance (MANOVA).

RESULTS

A significant foot strike position (FSP)×speed interaction in each of the foot regions indicated that plantar loading differed based on FSP across the different speeds. The RFSP provided the highest total forces across the foot while the pressures displayed in subjects with a non-rearfoot strike pattern (NRFSP) was more similar between each of the metatarsals.

CONCLUSIONS

The majority of subjects ran barefoot with a NRFSP and demonstrated lower total forces and more uniform force distribution across the metatarsal regions. This may have an influence in injuries sustained in barefoot running.

Kinematic and kinetic comparison of barefoot and shod running in mid/forefoot and rearfoot strike runners

Barefoot running has been associated with decreased stride length and switching from a rearfoot strike (RFS) pattern to a mid/forefoot strike (M/FFS) pattern. However, some individuals naturally contact the ground on their mid/forefoot, even when wearing cushioned running shoes. The purpose of this study was to determine if the mechanics of barefoot running by natural shod RFS runners differed from natural shod M/FFS runners. Twenty habitually shod runners (ten natural M/FFS and ten natural RFS) participated in this study. Three-dimensional motion analysis and ground reaction force data were captured as subjects ran at their preferred running speed in both barefoot and shod conditions. M/FFS experienced only a decrease in stride length when switching from shod to barefoot running. Whereas, when switching from shod to barefoot running, RFS individuals experienced a decrease in stride length, switched to a plantarflexed position at ground contact and saw reduced impact peak magnitudes. These results suggest that when barefoot, the RFS group ran similar to the M/FFS group running barefoot or shod.

Minimalist, standard and no footwear on static and dynamic postural stability following jump landing

In recreational sports, uncushioned, light-weight and minimalist shoes are increasingly used to imitate barefoot situations. Uncertainty exists whether these shoes provide sufficient stability during challenging movements. In this randomised crossover study, 35 healthy distance runners performed jump landing stabilisation and single-leg stance tests on a force plate, using four conditions in random order: barefoot, uncushioned minimalist shoes, cushioned ultraflexible shoes and standard running shoes. Ground reaction force (GRF) and centre of pressure (COP) data were used to determine unilateral jump landing stabilisation time and COP sway velocity during single-leg stance. Repeated measures analysis of variance revealed significant footwear interactions for medial-lateral (p < 0.001) and anterior-posterior COP sway velocity during standing (p < 0.001). The barefoot condition produced significantly greater postural sway velocities (p < 0.001) compared to all footwear conditions. No significant effects were found for jump landing stabilisation time. In conclusion, the results of this study indicate that increased shoe flexibility and reduced sole support have no, or only minor influence on static and dynamic postural control, and therefore, may not increase the risk of traumatic events during sports activities. However, barefoot conditions should be considered carefully when adequate postural control is needed.

Effects of footwear on three-dimensional tibiotalar and subtalar joint motion during running

Running is a popular form of recreation, but injuries are common and may be associated with abnormal joint motion. The objective of this study was to determine the effect of three footwear conditions - barefoot (BF), an ultraflexible training shoe (FREE), and a motion control shoe (MC) - on 3D foot and ankle motion. Dynamic, biplane radiographic images were acquired from 12 runners during overground running. 3D rotations of the tibiotalar and subtalar joints were quantified in terms of plantarflexion/dorsiflexion (PF/DF), inversion/eversion (IN/EV) and internal/external rotation (IR/ER). Across the early stance phase (defined as footstrike to heel-off), BF running demonstrated greater tibiotalar joint range of motion for PF/DF (28.2 ± 8.3°) and IR/ER (7.0 ± 1.4°) than the shod conditions (FREE: PF/DF=15.1 ± 5.9°, IR/ER=4.8 ± 2.1°; MC: PF/DF=15.0 ± 6.2°, IR/ER=4.3 ± 0.7°). Also at the tibiotalar joint, BF running resulted in a position significantly more plantarflexed (BF: 2.0 ± 12.5°, FREE: 15.7 ± 12.2°, MC: 16.5 ± 9.3°) and internally rotated (BF: 12.9 ± 4.5°, FREE: 10.7 ± 4.3°, MC: 10.6 ± 3.9°) at footstrike compared to both shod conditions. No differences were detected between the shod conditions at any point in the early stance phase at the tibiotalar joint. The MC condition demonstrated significant differences compared to FREE at several points throughout the early stance phase at the subtalar joint, with the greatest differences seen at 30% in PF/DF (MC -1.4 ± 8.8°: FREE: -0.5 ± 9.0°), IN/EV (MC -8.1 ± 5.7°: FREE -6.3 ± 5.5°) and IR/ER (MC -9.5 ± 5.3°: FREE: -8.7 ± 5.2°). These findings indicate that footwear has subtle effects on joint motion mainly between BF and shod conditions at the tibiotalar joint and between shod conditions at the subtalar joint.

Ankle plantarflexion strength in rearfoot and forefoot runners: a novel clusteranalytic approach

The purpose of the present study was to test for differences in ankle plantarflexion strengths of habitually rearfoot and forefoot runners. In order to approach this issue, we revisit the problem of classifying different footfall patterns in human runners. A dataset of 119 subjects running shod and barefoot (speed 3.5m/s) was analyzed. The footfall patterns were clustered by a novel statistical approach, which is motivated by advances in the statistical literature on functional data analysis. We explain the novel statistical approach in detail and compare it to the classically used strike index of Cavanagh and Lafortune (1980). The two groups found by the new cluster approach are well interpretable as a forefoot and a rearfoot footfall groups. The subsequent comparison study of the clustered subjects reveals that runners with a forefoot footfall pattern are capable of producing significantly higher joint moments in a maximum voluntary contraction (MVC) of their ankle plantarflexor muscles tendon units; difference in means: 0.28Nm/kg. This effect remains significant after controlling for an additional gender effect and for differences in training levels. Our analysis confirms the hypothesis that forefoot runners have a higher mean MVC plantarflexion strength than rearfoot runners. Furthermore, we demonstrate that our proposed stochastic cluster analysis provides a robust and useful framework for clustering foot strikes.

Effects of barefoot and barefoot inspired footwear on knee and ankle loading during running

BACKGROUND

Recreational runners frequently suffer from chronic pathologies. The knee and ankle have been highlighted as common injury sites. Barefoot and barefoot inspired footwear have been cited as treatment modalities for running injuries as opposed to more conventional running shoes. This investigation examined knee and ankle loading in barefoot and barefoot inspired footwear in relation to conventional running shoes.

METHOD

Thirty recreational male runners underwent 3D running analysis at 4.0m·s(-1). Joint moments, patellofemoral contact force and pressure and Achilles tendon forces were compared between footwear.

FINDINGS

At the knee the results show that barefoot and barefoot inspired footwear were associated with significant reductions in patellofemoral kinetic parameters. The ankle kinetics indicate that barefoot and barefoot inspired footwear were associated with significant increases in Achilles tendon force compared to conventional shoes.

INTERPRETATION

Barefoot and barefoot inspired footwear may serve to reduce the incidence of knee injuries in runners although corresponding increases in Achilles tendon loading may induce an injury risk at this tendon.

Is midsole thickness a key parameter for the running pattern?

Many studies have highlighted differences in foot strike pattern comparing habitually shod runners who ran barefoot and with running shoes. Barefoot running results in a flatter foot landing and in a decreased vertical ground reaction force compared to shod running. The aim of this study was to investigate one possible parameter influencing running pattern: the midsole thickness. Fifteen participants ran overground at 3.3 ms(-1) barefoot and with five shoes of different midsole thickness (0 mm, 2 mm, 4 mm, 8 mm, 16 mm) with no difference of height between rearfoot and forefoot. Impact magnitude was evaluated using transient peak of vertical ground reaction force, loading rate, tibial acceleration peak and rate. Hip, knee and ankle flexion angles were computed at touch-down and during stance phase (range of motion and maximum values). External net joint moments and stiffness for hip, knee and ankle joints were also observed as well as global leg stiffness. No significant effect of midsole thickness was observed on ground reaction force and tibial acceleration. However, the contact time increased with midsole thickness. Barefoot running compared to shod running induced ankle in plantar flexion at touch-down, higher ankle dorsiflexion and lower knee flexion during stance phase. These adjustments are suspected to explain the absence of difference on ground reaction force and tibial acceleration. This study showed that the presence of very thin footwear upper and sole was sufficient to significantly influence the running pattern.

Low-frequency accelerations over-estimate impact-related shock during walking

During gait, a failure to acknowledge the low-frequency component of a segmental acceleration signal will result in an overestimation of impact-related shock and may lead to inappropriately drawn conclusions. The present study was undertaken to investigate the significance of this low-frequency component in two distinctly different modalities of gait: barefoot (BF) and shod (SHOD) walking. Twenty-seven participants performed five walking trials at self-selected speed in each condition. Peak positive accelerations (PPA) at the shank and spine were first derived from the time-domain signal. The raw acceleration signals were then resolved in the frequency-domain and the active (low-frequency) and impact-related components of the power spectrum density (PSD) were quantified. PPA was significantly higher at the shank (P<0.0001) and spine (P=0.0007) in the BF condition. In contrast, no significant differences were apparent between conditions for shank (P=0.979) or spine (P=0.178) impact-related PSD when the low-frequency component was considered. This disparity between approaches was due to a significantly higher active PSD in both signals in the BF condition (P<0.0001; P=0.008, respectively), due to kinematic differences between conditions (P<0.05). These results indicate that the amplitude of the low-frequency component of an acceleration signal during gait is dependent on knee and ankle joint coordination behaviour, and highlight that impact-related shock is more accurately quantified in the frequency-domain following subtraction of this component.

shod conditions: a systematic review

Although it could be perceived that there is extensive research on the impact attenuation characteristics of shoes, the approach and findings of researchers in this area are varied. This review aimed to clarify the effect of shoes on impact attenuation to the foot and lower leg and was limited to those studies that compared the shoe condition(s) with barefoot. A systematic search of the literature yielded 26 studies that investigated vertical ground reaction force, axial tibial acceleration, loading rate and local plantar pressures. Meta-analyses of the effect of shoes on each variable during walking and running were performed using the inverse variance technique. Variables were collected at their peak or at the impact transient, but when grouped together as previous comparisons have done, shoes reduced local plantar pressure and tibial acceleration, but did not affect vertical force or loading rate for walking. During running, shoes reduced tibial acceleration but did not affect loading rate or vertical force. Further meta-analyses were performed, isolating shoe type and when the measurements were collected. Athletic shoes reduced peak vertical force during walking, but increased vertical force at the impact transient and no change occurred for the other variables. During running, athletic shoes reduced loading rate but did not affect vertical force. The range of variables examined and variety of measurements used appears to be a reason for the discrepancies across the literature. The impact attenuating effect of shoes has potentially both adverse and beneficial effects depending on the variable and activity under investigation.