Title: The influence of barefoot running on running kinetics. Objectives: The aim of this work is to assess the influence of different footwear (regular running shoes, barefoot footwear and barefoot running) on footstrike (rear-foot strike, mid-foot strike and fore-foot strike) during running and evaluate the action of reaction forces in different types of footstrike. Methods: In this study participated 11 runners (only men), who were divided in three groups based on their preferred footwear. Kinetic data (reaction forces) were collected by using a Kistler force plate, which was crossed by the participants with subjectively chosen speed. Kinematic parameters of running (speed) and video recordings of a single footstrikes were obtained by using a Qualisys system of optoelectronic stereophotogrammetry. All the measurements occurred during one day. Collected data were exported to Microsoft Excel 2013 programme, where the graphs of reaction forces were created and to Qualisys Track Manager software. Assessment was based on created graphs and video recordings. Results: The results show that runners wearing regular running shoes preferred a rear- foot strike, while among runners in barefoot footwear a fore-foot strike than mid-foot strike prevailed a bit. Among barefoot runners dominated a fore-foot...

This present study was intended to investigate muscle activation patterns throughout the barbell back squat and determine if there are any differences found in EMG responses among individuals wearing weightlifting shoes and barefooted individuals. The hypothesis was that weightlifting shoes would generate significantly greater muscle activation patterns throughout the barbell back squat due to the rigid structure and raised heal in the shoe design. EMG patterns from six superficial lower extremity muscles were recorded from 12 subjects (means: 22.67 ± 2.39 age, 172,28 ± 14.04 cm height, 74.88 ± 16.11 kg mass), each meeting a specific inclusion criteria. Data collection occurred over three subject visits to determine one repetition maximum [1RM] (Day 1), conduct maximal contraction tests (Day 2), and finally to perform squat tests with the two footwear conditions (Day 3). Data was collected at 80% of the participants’ 1RM utilizing both weightlifting shoes and barefoot conditions, and EMG activity was recorded for data analysis. Paired-sample T-tests were calculated to check for any significant differences among footwear conditions, and 2X2 ANOVA testing was used to determine if any significant changes occurred among footwear conditions in the eccentric and concentric portions of the barbell back squat. The study found two main components. The first was that several muscles showed differences between eccentric and concentric phases in regards to average muscle activity. However, none of the observed muscles showed significant differences between the two footwear conditions in regard to EMG activity.

There are many different types of footwear available for runners in today's market. Many of these shoes claim to improve a runner's efficiency by altering their stride mechanics. Minimalist footwear claims to aid runners in running more on their forefeet whereas more traditional footwear provides more cushioning specifically for a heel-first landing. The purpose of this research was to determine if runners who were accustomed to running in traditional footwear would acutely alter their running biomechanics when they ran barefoot or in various types of minimalist footwear. Twelve subjects, who were accustomed to running in traditional 12 mm heel/toe differential footwear, ran in five footwear conditions on a treadmill at a controlled pace for 2 minutes after warming up in each condition for 5 minutes. While running in 12 mm heel/toe differential footwear compared to barefoot, subjects ran with a significantly longer ground time, a slower stride rate and greater vertical oscillation. There were not any significant differences in kinematic and kinetic variables when running in the shod conditions despite the varying heel/toe differentials. Foot strike angle did not change under any of the conditions either. Running barefoot proved to be different than running in footwear in that stride rate increased, ground time decreased and vertical oscillation decreased. There were not any significant acute differences between any of the footwear conditions despite having different heel/toe differentials in subjects accustomed to wearing traditional heel-drop footwear. Wearing minimalist or cushioned minimal footwear appears to not be an effective means of changing running mechanics acutely but may need repeated bouts to alter running mechanics.

Tese de mestrado integrado. Bioengenharia (Engenharia Biomédica). Universidade do Porto. Faculdade de Engenharia. 2011

Minimal footwear sales have encountered rapid growth over the last several years. Minimal footwear are often constructed with thin basic uppers and thin, flexible midsoles. It is likely that running in minimal footwear will require adaptation and adjustments as the amount of cushioning and the geometry of the foot/ground interface will be substantially different than what many are accustomed to. This research investigated the effect footwear cushioning amount and the running surface had on running patterns. Study 1 (Chapter IV) utilized two different running footwear conditions and two different cushioned treadmill conditions, as well as a barefoot condition, to investigate the effect cushioning magnitude and mode had on running patterns. Subjects ran for six minutes at 3.0 m/s for each footwear/surface condition while kinematics and acceleration data were collected. Study 2 (Chapter V) utilized three footwear conditions as well as a barefoot condition to investigate the effect of running in minimal footwear for the first time. Subjects ran for six minutes at 3.0 m/s while wearing each of the four conditions on an aluminum belt treadmill while kinematic and acceleration data were collected. The three footwear conditions were very similar except for the amount of underfoot material (foam) which varied from very little in the most minimal condition to a typical training footwear amount in the thickest condition. Study 3 (Chapter VI) utilized the same three footwear conditions worn in study 2. Subjects ran for 30 minutes at 3.0 m/s wearing each of the three footwear conditions while kinematic and acceleration data were collected in order to investigate the response to minimal footwear over the course of a sustained run. Results of Study 1 suggest that the amount of underfoot cushioning as well as how that cushioning was applied (footwear vs. surface) were both important and affected adjustments made during the run. The foot was more horizontal, the ankle joint complex more plantar flexed, and the knee more flexed in the sagittal plane at TD when running barefoot compared to all other conditions. Peak acceleration values were reduced for the most cushioned condition compared to all others. The thigh segment was more vertical at TD and peak tibial internal rotation at midstance was reduced when footwear were worn. This indicated cushioning provided through footwear altered running patterns compared to cushioning provided through the surface. More investigation is necessary to fully understand all the factors involved, but our research showed that cushioning magnitude is not the only factor affecting running patterns when footwear or running surface is altered. Some Study 2 dependent variables indicated running patterns to be significantly different for both barefoot and very minimal footwear conditions compared to footwear with thicknesses more similar to typical training footwear. Other dependent variables showed barefoot to separate from all footwear conditions implying that unique strategies were utilized for barefoot running even when compared to minimal footwear providing very little cushioning or protection. Peak accelerations implied that cushioning limited the shock transferred to the tibia and the head. Most coordination measures implied barefoot running to be significantly more variable than running in minimal running shoes. Adaptations due to running in footwear with unknown cushioning characteristics occurred quickly, in as few as six to eight steps. Kinematic adjustments were also occurring later in the six minute run. Study 3 kinematic and acceleration dependent variables indicated adjustments were made to running patterns as a result of changes in the amount of underfoot material. The foot segment was less horizontal and the AJC more dorsiflexed for the thick condition compared to both others. These changes did not completely compensate for changes in underfoot material however, as peak accelerations at the tibia and the head were increased as underfoot material was reduced. Runners were found to adjust running patterns as the thirty minute run progressed regardless of footwear condition. Several kinematic dependent variables were found to significantly increase or decrease as the 30 minute run progressed. In summary, the amount of cushioning and the mode of cushioning were found to effect running patterns. Given these findings, it is not surprising adaptations were found when comparing running in minimal footwear to running in footwear with more typical midsole thicknesses. Cushioning magnitude and the geometry of the foot/ground interface were substantially different between these footwear conditions. Although the thin condition provided almost no cushioning, differences were still shown between barefoot and this condition. Barefoot running may require a unique solution even compared to running in extremely minimal footwear. When runners wore minimal running shoes for the first time, some adaptations occurred quickly; however, adjustments were still occurring much later into the six and 30 minute runs. Runners who purchase minimal footwear can expect changes in running patterns.

Background: In years 2011-2014, 8.6 million sports-related injuries were reported each year and falls have been identified as a main cause. Purpose: To determine the impact of foot type, quadriceps angle, and Vibram™ footwear on postural stability. Methods: Twentyour males (age 21.38±2.50yr; height 1.74±0.06m; mass 71.24±10.37kg) were categorized as pronated, supinated, and neutral feet using FPI and bilateral quadriceps angles were measured. Participants were tested on barefoot, Vibram™ Bikila and Vibram™ Trek (VT), on stable/unstable, bilateral/unilateral, eyes open/closed conditions. Sway variables were analyzed using 3(foot type) × 3(footwear) repeated measures ANOVA. Pearson product correlation was performed for quadriceps angle with sway variables. Results: Footwear main effect significance was evident in all conditions except stable unilateral eyes open condition, with lower values for barefoot followed by VT. Conclusion: Static balance in BF is superior to shod conditions in all situations except the extremely challenging condition, in which VT showed greater balance.

Author: Bc. Zuzana Vacková Title: Effect of Barefoot shoes on the footprint loading Objectives: The aim of this experiment is to evaluate if barefoot shoes affect the size of vertical component of contact force during walking on a smooth non- abrasive surface during normal conditions. Furthermore to find out which parameters can be used to monitor the degree of convergence foot behaviour during the stance phase of gait cycle with the barefoot and barefoot shoes. Methods: Seven probands (4 women, 3 men) aged 23 to 25 years participated at the study. The dynamic gait parameters (reaction forces from the pad) were measured using Kistler force plates in the extreme load laboratory at FTVS UK. Probands after introduction to the experiment went repeatedly over the power plate subjectively comfortable speed. The first measurement were done while walking in the barefoot type of shoes. The second measurement was barefoot walking. It was a one-time measurement. The obtained data were exported from BioWare® program into MS Excel. The final data processing was carried out in the MatLab program, where the necessary graphs of reaction forces and their evaluation were created. Results: All contact forces and their resultant and CoP coordinates were recorded during measurements. Only the vertical contact force...

The diploma thesis deals with the possible influence of barefoot (or minimalist) shoes on the kinesiological parameters of gait and possible changes in the stability of gait and standing. The theoretical section briefly describes the anatomy of the human foot, foot arches, foot movements and the gait kinesiology. The next chapter deals with the issue of walking in barefoot shoes and explaining the basic parameters of barefoot shoes. The theoretical section concludes with a summary of the results of studies already conducted on this issue. In the practical part, we did our own research on selected gait and standing parameters, which can be affected by changing the shoe type. Participants switched to a period of approximately six months from wearing conventional shoes to barefoot shoes, and the measurements were taken twice, before and after adaptation to barefoot shoes. To objectify the results, the same measurements were taken in a control group that did not change shoes. Five parameters were selected to evaluate changes of gait and three parameters related to standing stability. Keywords Barefoot, minimalistic shoes, gait, gait analysis, stance analysis, stability

The purpose of the study was to compare the kinematics of the barbell back squat between two footwear conditions and to evaluate the results with respect to recommendations put forth in the National Strength and Conditioning Association position statement for proper squat technique. Twenty-five subjects with 5 - 7 years of resistance training experience participated. Selected kinematics were measured during a 60% of 1RM barbell back squat in both barefoot and athletic shoe conditions. Paired-samples T tests were performed to compare the two footwear conditions. Significant differences were found in trunk (50.72±8.27 vs. 46.97±9.87), thigh (20.94±10.19 vs. 24.42±11.11), and shank segment angles (59.47±5.54 vs. 62.75±6.17), and knee joint angles (81.33±13.70 vs. 88.32±15.45) at the peak descent position. Based on the kinematic analysis of the barefoot squat, two kinematic advantages are countered by two disadvantages. Coaches and instructors should acknowledge these results with respect to a performer's capability, and be aware the advantages and disadvantages of barefoot squat from a kinematic perspective.

The purpose of the study was to compare the kinematics of the barbell back squat between two footwear conditions and to evaluate the results with respect to recommendations put forth in the National Strength and Conditioning Association position statement for proper squat technique. Twenty-five subjects with 5 - 7 years of resistance training experience participated. Selected kinematics were measured during a 60% of 1RM barbell back squat in both barefoot and athletic shoe conditions. Paired-samples T tests were performed to compare the two footwear conditions. Significant differences were found in trunk (50.72±8.27 vs. 46.97±9.87), thigh (20.94±10.19 vs. 24.42±11.11), and shank segment angles (59.47±5.54 vs. 62.75±6.17), and knee joint angles (81.33±13.70 vs. 88.32±15.45) at the peak descent position. Based on the kinematic analysis of the barefoot squat, two kinematic advantages are countered by two disadvantages. Coaches and instructors should acknowledge these results with respect to a performer's capability, and be aware the advantages and disadvantages of barefoot squat from a kinematic perspective.