Foot Strike Patterns Differ Between Children and Adolescents Growing up Barefoot vs. Shod.
ABSTRACT: 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 (ORbarefoot-jogging=0.82, 95% CI, 0.71 to 0.96, p=0.014; ORbarefoot-running=0.58, 95% CI, 0.50 to 0.67, p<0.001 and ORshod-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 influenced 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.
Project description:Runners are often categorized as forefoot, midfoot or rearfoot strikers, but how much and why do individuals vary in foot strike patterns when running on level terrain? This study used general linear mixed-effects models to explore both intra- and inter-individual variations in foot strike pattern among 48 Kalenjin-speaking participants from Kenya who varied in age, sex, body mass, height, running history, and habitual use of footwear. High speed video was used to measure lower extremity kinematics at ground contact in the sagittal plane while participants ran down 13 meter-long tracks with three variables independently controlled: speed, track stiffness, and step frequency. 72% of the habitually barefoot and 32% of the habitually shod participants used multiple strike types, with significantly higher levels of foot strike variation among individuals who ran less frequently and who used lower step frequencies. There was no effect of sex, age, height or weight on foot strike angle, but individuals were more likely to midfoot or forefoot strike when they ran on a stiff surface, had a high preferred stride frequency, were habitually barefoot, and had more experience running. It is hypothesized that strike type variation during running, including a more frequent use of forefoot and midfoot strikes, used to be greater before the introduction of cushioned shoes and paved surfaces.
Project description:Background:Anecdotally, a wide variety of benefits of barefoot running have been advocated by numerous individuals. The influence of the alterations in the properties of the shoe on the running movement has been demonstrated in adults at submaximal jogging speeds. However, the biomechanical differences between shod and barefoot running in children at sprinting speeds and the potential developmental implications of these differences are still less examined. The purpose was to determine the potential differences in habitually shod children's sprint kinematics between shod and barefoot conditions. Methods:Ninety-four children (51 boys and 43 girls; 6-12 years-old; height, 135.0 ± 0.12 m; body mass, 29.0 ± 6.9 kg) performed 30 m maximal sprints from standing position for each of two conditions (shod and barefoot). To analyze sprint kinematics within sagittal plane sprint kinematics, a high-speed camera (300 fps) was set perpendicular to the runway. In addition, sagittal foot landing and take-off images were recorded for multiple angles by using five high-speed cameras (300 fps). Spatio-temporal variables, the kinematics of the right leg (support leg) and the left leg (recovery leg), and foot strike patterns: rear-foot strike (RFS), mid-foot strike (MFS), and fore-foot strike (FFS) were investigated. The paired t-test was used to test difference between shod and barefoot condition. Results:Barefoot sprinting in habitually shod children was mainly characterized by significantly lower sprint speed, higher step frequency, shorter step length and stance time. In shod running, 82% of children showed RFS, whereas it decreased to 29% in barefoot condition. The touch down state and the subsequent joint movements of both support and recovery legs during stance phase were significantly altered when running in condition with barefoot. Discussion:The acute effects of barefoot sprinting was demonstrated by significantly slower sprinting speeds that appear to reflect changes in a variety of spatiotemporal parameters as well as lower limb kinematics. It is currently unknown whether such differences would be observed in children who typically run in bare feet and what developmental benefits and risks may emerge from increasing the proportion of barefoot running and sprinting in children. Future research should therefore investigate potential benefits that barefoot sprinting may have on the development of key physical fitness such as nerve conduction velocity, muscular speed, power, and sprinting technique and on ways to minimize the risk of any acute or chronic injuries associated with this activity.
Project description:BACKGROUND: The effect of footwear on the gait of children is poorly understood. This systematic review synthesises the evidence of the biomechanical effects of shoes on children during walking and running. METHODS: Study inclusion criteria were: barefoot and shod conditions; healthy children aged ? 16 years; sample size of n > 1. Novelty footwear was excluded. Studies were located by online database-searching, hand-searching and contact with experts. Two authors selected studies and assessed study methodology using the Quality Index. Meta-analysis of continuous variables for homogeneous studies was undertaken using the inverse variance approach. Significance level was set at P < 0.05. Heterogeneity was measured by I2. Where I2 > 25%, a random-effects model analysis was used and where I2 < 25%, a fixed-effects model was used. RESULTS: Eleven studies were included. Sample size ranged from 4-898. Median Quality Index was 20/32 (range 11-27). Five studies randomised shoe order, six studies standardised footwear. Shod walking increased: velocity, step length, step time, base of support, double-support time, stance time, time to toe-off, sagittal tibia-rearfoot range of motion (ROM), sagittal tibia-foot ROM, ankle max-plantarflexion, Ankle ROM, foot lift to max-plantarflexion, 'subtalar' rotation ROM, knee sagittal ROM and tibialis anterior activity. Shod walking decreased: cadence, single-support time, ankle max-dorsiflexion, ankle at foot-lift, hallux ROM, arch length change, foot torsion, forefoot supination, forefoot width and midfoot ROM in all planes. Shod running decreased: long axis maximum tibial-acceleration, shock-wave transmission as a ratio of maximum tibial-acceleration, ankle plantarflexion at foot strike, knee angular velocity and tibial swing velocity. No variables increased during shod running. CONCLUSIONS: Shoes affect the gait of children. With shoes, children walk faster by taking longer steps with greater ankle and knee motion and increased tibialis anterior activity. Shoes reduce foot motion and increase the support phases of the gait cycle. During running, shoes reduce swing phase leg speed, attenuate some shock and encourage a rearfoot strike pattern. The long-term effect of these changes on growth and development are currently unknown. The impact of footwear on gait should be considered when assessing the paediatric patient and evaluating the effect of shoe or in-shoe interventions.
Project description:Background: The objective of this study was to evaluate the association between growing up barefoot or shod and the development of motor performance during childhood and adolescence. Methods: Habitual barefoot and shod children and adolescents between 6 and 18 years were recruited in South Africa and Germany. Participants completed balance, standing long jump and 20 m sprint tests in barefoot and shod conditions. Outcomes were analyzed in separate mixed-effects linear regressions for three age groups according to stages of development (6-10, 11-14, and 15-18 years). All models were adjusted for confounders: sex, ethnicity, BMI, PAQ score and order of tests (barefoot vs. shod). Results: Three hundred and eight-five habitually barefoot and 425 habitually shod children participated. Significant age by footwear effects were found for the jump (p = 0.032) and sprint test (p = 0.041). Habitually barefoot children aged 6-10 years scored higher in the balance test (p = 0.015) and standing long jump (p = 0.005) whereas habitually shod children sprinted faster (p < 0.001). Faster sprint times were found for habitually shod participants between 11 and 14 years (p < 0.001). Habitually barefoot adolescents between 15 and 18 years of age showed a greater long jump distance (p < 0.001) but slower sprint times (p = 0.014) than shod adolescents. Conclusions: The results emphasize the importance of footwear habits for the development of motor skills during childhood and adolescence. Regular physical activities without footwear may be beneficial for the development of jumping and balance skills, especially in the age of 6 to 10 years.
Project description:<h4>Background</h4>Although minimalist footwear is increasingly popular among runners, claims that minimalist footwear enhances running biomechanics and efficiency are controversial.<h4>Hypothesis</h4>Minimalist and barefoot conditions improve running efficiency when compared with traditional running shoes.<h4>Study design</h4>Randomized crossover trial.<h4>Level of evidence</h4>Level 3.<h4>Methods</h4>Fifteen experienced runners each completed three 90-second running trials on a treadmill, each trial performed in a different type of footwear: traditional running shoes with a heavily cushioned heel, minimalist running shoes with minimal heel cushioning, and barefoot (socked). High-speed photography was used to determine foot strike, ground contact time, knee angle, and stride cadence with each footwear type.<h4>Results</h4>Runners had more rearfoot strikes in traditional shoes (87%) compared with minimalist shoes (67%) and socked (40%) (P = 0.03). Ground contact time was longest in traditional shoes (265.9 ± 10.9 ms) when compared with minimalist shoes (253.4 ± 11.2 ms) and socked (250.6 ± 16.2 ms) (P = 0.005). There was no difference between groups with respect to knee angle (P = 0.37) or stride cadence (P = 0.20). When comparing running socked to running with minimalist running shoes, there were no differences in measures of running efficiency.<h4>Conclusion</h4>When compared with running in traditional, cushioned shoes, both barefoot (socked) running and minimalist running shoes produce greater running efficiency in some experienced runners, with a greater tendency toward a midfoot or forefoot strike and a shorter ground contact time. Minimalist shoes closely approximate socked running in the 4 measurements performed.<h4>Clinical relevance</h4>With regard to running efficiency and biomechanics, in some runners, barefoot (socked) and minimalist footwear are preferable to traditional running shoes.
Project description:Despite substantial recent interest in walking barefoot and in minimal footwear, little is known about potential differences in walking biomechanics when unshod versus minimally shod. To test the hypothesis that heel impact forces are similar during barefoot and minimally shod walking, we analysed ground reaction forces recorded in both conditions with a pedography platform among indigenous subsistence farmers, the Tarahumara of Mexico, who habitually wear minimal sandals, as well as among urban Americans wearing commercially available minimal sandals. Among both the Tarahumara (n?=?35) and Americans (n?=?30), impact peaks generated in sandals had significantly (p?<?0.05) higher force magnitudes, slower loading rates and larger vertical impulses than during barefoot walking. These kinetic differences were partly due to individuals' significantly greater effective mass when walking in sandals. Our results indicate that, in general, people tread more lightly when walking barefoot than in minimal footwear. Further research is needed to test if the variations in impact peaks generated by walking barefoot or in minimal shoes have consequences for musculoskeletal health.
Project description:The development of the human foot is crucial for motor learning in children and adolescents as it ensures the basic requirements for bipedal locomotion and stable standing. Although there is an ongoing debate of the advantages and disadvantages of early and permanent footwear use, the influence of regular barefootness on foot characteristics in different stages of child development has not been extensively evaluated. A multicenter epidemiological study was conducted to compare the foot morphology between habitually barefoot children and adolescents (N?=?810) to age-, sex- and ethnicity-matched counterparts that are used to wearing shoes. While controlling for confounders, we found that habitual footwear use has significant effects on foot-related outcomes in all age groups, such as a reduction in foot arch and hallux angles. The results indicate an impact of habitual footwear use on the development of the feet of children and adolescents. Therefore, growing up barefoot or shod may play an important role for childhood foot development, implying long-term consequences for motor learning and health later in life.
Project description:Short-term effects of barefoot and simulated barefoot running have been widely discussed in recent years. Consequences of adopting barefoot running for a long period, including as a training approach, still remain unknown. The present study evaluated the influence of 16 weeks of progressive barefoot running training on impact force and muscle activation in habitual shod runners. Six habitual shod runners (3 men and 3 women, 29.5 ± 7.3 years) were tested barefoot (BF) and shod (SH), before and after 16 weeks of progressive barefoot running training. Tests consisted of running on instrumented treadmill at 9 km/h, for 10 minutes in each experimental condition. Nine data acquisitions (10 s) of vertical ground reaction force (VGRF) and electromyographic (EMG) signal were conducted in each experimental condition for each test. BF training was effective to alter VGRF and EMG parameters of running in habitual shod runners, regardless of footwear condition (SH or BF). The magnitude of first peak of VGRF (Fy1) and the impulse of the first 50 ms decreased after training for BF and SH (p<0.01). The activation reduced from PRE to POST training for four muscles in BF running (p<0.001), whereas only muscle gastrocnemius lateralis decreased significantly its activation (p<0.01) in SH running. A 16-week progressive barefoot running training seems to be an effective training strategy to reduce impact force, improve shock attenuation and to decrease muscle activation intensity, not only in BF running, but also in SH running, although BF condition seems to be more influenced by BF training.
Project description:Previous research on elderly people has suggested that footwear may improve neuromuscular control of motion. If footwear does in fact improve neuromuscular control, then such an influence might already be present in young, healthy adults. A feature that is often used to assess neuromuscular control of motion is the level of gait asymmetry. The objectives of the study were (a) to develop a comprehensive asymmetry index (CAI) that is capable of detecting gait asymmetry changes caused by external boundary conditions such as footwear, and (b) to use the CAI to investigate whether footwear influences gait asymmetry during running in a healthy, young cohort. Kinematic and kinetic data were collected for both legs of 15 subjects performing five barefoot and five shod over-ground running trials. Thirty continuous gait variables including ground reaction forces and variables of the hip, knee, and ankle joints were computed for each leg. For each individual, the differences between the variables for the right and left leg were calculated. Using this data, a principal component analysis was conducted to obtain the CAI. This study had two main outcomes. First, a sensitivity analysis suggested that the CAI had an improved sensitivity for detecting changes in gait asymmetry caused by external boundary conditions. The CAI may, therefore, have important clinical applications such as monitoring the progress of neuromuscular diseases (e.g. stroke or cerebral palsy). Second, the mean CAI for shod running (131.2 ± 48.5; mean ± standard deviation) was significantly lower (p = 0.041) than the CAI for barefoot running (155.7 ± 39.5). This finding suggests that in healthy, young adults gait asymmetry is reduced when running in shoes compared to running barefoot, which may be a result of improved neuromuscular control caused by changes in the afferent sensory feedback.
Project description:The purpose of this study was to investigate the variations of arch index from static standing to dynamic walking and running; furthermore, the interlimb symmetry was checked in the two populations. A total of eighty male participants were recruited for this study, with forty habitually barefoot and forty habitually shod males, respectively. Arch index (AI) was calculated following the previously established "gold standard" measurement via contact areas recorded from EMED. Repeated measure analysis of variance (ANOVA) was employed to compare the difference between static and dynamic walking and running arch index. Paired-samples t-test and symmetry index (SI) were used to investigate the symmetry of the left foot arch index and right foot arch index. It was found that the dynamic arch index was significantly higher than the static arch index in barefoot and shod males, showing an increase from static weight-bearing standing to dynamic walking and running. However, interlimb (right-left) symmetry in the foot arch index was observed in the two populations. Dynamic changes of the arch index may provide implications that need to be considered while designing shoe lasts or insoles. Knowledge of the healthy arch index range reported from this study could also be used as a standard baseline to probe into foot and arch disorders.