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Influence of basketball shoe mass, traction and bending stiffness on athletic performance

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... In general, an athlete needs to have enough traction between the shoe and the sport surface to prevent slippage while generating the appropriate ground reaction forces for optimal performance. Many studies have been conducted investigating the influence of outsole traction on performance [13][14][15][16]. The results of these studies are generally in agreement, indicating that traction can have a large influence on performance if the available traction of the footwear (the maximum amount of traction that can occur for a specific shoe-surface combination, usually measured by mechanical testing) is greater than the required or utilized traction of the athletes (the amount of outsole traction that the athletes need to perform the specific movement) [16]. ...
... Similarly, when basketball players performed sprinting, jumping, and cutting drills wearing shoes of low, medium, and high outsole traction, performance differences of over 33 % occurred when comparing the low-traction shoe to the high-traction shoe. However, there was only a 4 % difference in performance when comparing the medium traction shoe to the high-traction shoe [15]. These studies confirm that there will be minimal performance differences between shoes that provide an available traction that exceeds the traction required by the athletes during maximal effort. ...
... Another aspect of footwear with mounting evidence in terms of influencing performance is forefoot stiffness. Numerous studies have shown that increasing the bending stiffness of shoes along the metatarsophalangeal (MTP) joint results in improved performance in terms of long distance running economy [41], improved sprinting and cutting drill performance [15,42] and improved vertical jumping performance [43]. However, the degree of increased stiffness to which an athlete experiences these performance increases is very individualized with no indication of the underlying variable in determining an athlete's optimal stiffness. ...
Article
Advances in sport equipment have revolutionized athletic competition with engineers developing equipment that can enhance performance. However, not all athletes are able to benefit from the new, ideal equipment, with some athletes performing worse. Although the engineering may be sound, the interaction between the piece of equipment, the athlete, and the action is missing. The purely mechanical system of the piece of equipment becomes a biomechanical system once it is interacting with the athlete. Research into the underlying mechanisms of performance in sport has relied heavily on biomechanical studies. The review of these studies has identified important performance and injury variables that can be influenced by sport equipment. This baseline information helps provide a fundamental understanding of human performance that guide equipment designers and developers. A flawlessly engineered mechanical piece of sport equipment can still fail if the athlete–equipment interaction is not properly addressed in the design process. How an athlete uses a piece of equipment and furthermore how an athlete may change or adapt to changes in properties of a piece of equipment must be taken into consideration. Using properties of footwear as an example, research has provided understanding of the biomechanical limiting factors regarding the influence of footwear traction on athletic performance. Data on other footwear properties such as cushioning and forefoot bending stiffness are limited. Intrinsic musculoskeletal properties, such as the force–length and force–velocity relationships of skeletal muscle, can be exploited through equipment design, as has been shown during cycling. Modifications to equipment parameters can shift the operating range of an athlete within these relationships to maximize force or power output, which was shown during the development of the clap skate. Additionally, these properties vary slightly from athlete to athlete and minor adjustments to a piece of sporting equipment can help optimize individual athletes according to their specific biomechanical characteristics.
... Many modifications can be made to the shoe-surface interface to influence footwear traction. These modifications may be shoe outsole pattern and outsole material (Andreasson et al. 1986, Schlaepfer et al. 1983, Nigg and Yeadon 1987, Severn et al. 2010, Wannop and Worobets 2013, shoe cleating (Villwock et al. 2009, Wannop et al. 2009, Severn et al. 2010, Sterzing et al. 2010, and also sport surface material (Nigg and Yeadon 1987, Schlaepfer et al. 1983, Severn et al. 2011, Villwock et al. 2009, Wannop and Stefanyshyn 2012. While it has been shown that increasing footwear traction can lead to an increase in performance (Wannop and Worobets 2013), what is usually not considered when moving from one surface to another is the difference in the surface compliance. ...
... These modifications may be shoe outsole pattern and outsole material (Andreasson et al. 1986, Schlaepfer et al. 1983, Nigg and Yeadon 1987, Severn et al. 2010, Wannop and Worobets 2013, shoe cleating (Villwock et al. 2009, Wannop et al. 2009, Severn et al. 2010, Sterzing et al. 2010, and also sport surface material (Nigg and Yeadon 1987, Schlaepfer et al. 1983, Severn et al. 2011, Villwock et al. 2009, Wannop and Stefanyshyn 2012. While it has been shown that increasing footwear traction can lead to an increase in performance (Wannop and Worobets 2013), what is usually not considered when moving from one surface to another is the difference in the surface compliance. ...
... When comparing shoe mass between the indoor soccer shoe and the cleated soccer shoe, the indoor soccer shoe was heavier by 110 grams. While this mass difference may have an effect on performance of endurance activities (Frederick 1984, Divert et al. 2008, Lussiana et al. 2013, it has been shown that shoe mass has no effect on performance of short distance power activities when the athlete is not fatigued, such as at the beginning of a soccer match, and thus should not affect the results of the current study (Wannop and Worobets 2013). However, it is not known whether shoe mass may have an effect on performance under fatigued states, such as at the end of a soccer match, and this may affect the generalisability of our results to fatigued scenarios. ...
Article
Purpose: To determine how shoe-surface interaction, specifically traction and compliance, affects performance and biomechanics of soccer-related movements.Methods: Third generation artificial turf was installed in the laboratory to allow for kinetic and kinematic data collection both on the turf and on a laboratory surface (Pulastic sports surface). Twelve male athletes performed five 5 m sprint accelerations and five 180° sprint turns in three different shoe-surface conditions (indoor soccer shoe on the laboratory surface, indoor soccer shoe on the turf surface, soccer cleat on turf surface). Comparisons between the indoor shoe across surfaces indicated compliance effects and comparisons between the cleat and indoor shoe on turf indicated traction effects.Results: Performance increased for the sprint acceleration in the indoor shoe on the turf compared to the laboratory (1.04 s vs. 1.08 s); however, no further increase in acceleration performance occurred with the soccer cleat. For the turn movement, no change in performance occurred comparing the indoor shoe across surfaces however an increase in turn performance was seen when using the soccer cleat on turf compared to the indoor shoe (2.67 s vs. 2.56 s). The cleat had both increased utilised translational and rotational traction compared to the indoor shoe on turf for the turn movement. The cleat also resulted in increased ankle eversion moments as well as increased knee abduction and external rotation moments compared to the indoor shoe on the turf surface for the turn movement.Conclusion: Both compliance and traction shoe-surface characteristics affect performance; however, the effects of the different characteristics are different depending on the movement type.
... Increased LBS levels in athletic footwear have been shown to improve performance during the late (D. Stefanyshyn & Fusco, 2004) and early acceleration phase (first 5 and 10 m (Wannop, 2013;Wannop, Schrier, Worobets, & Stefanyshyn, 2015)) in sprinting. ...
... A significant decrease in performance was observed for the HS condition, which was accompanied by an increase in contact time and reduced average ground force application. This result is in disagreement with previous work on the effect of LBS on 5 and 10 m sprinting times (Wannop, 2013;Wannop et al., 2015). Still, the baseline footwear used in the present study is largely different to the basketball and American football footwear used in the cited studies, which might explain parts of the disagreement. ...
Article
Longitudinal bending stiffness (LBS) of footwear has been shown to affect performance in jumping and sprinting tasks. A detailed description of the mechanisms underlying these performance alterations is lacking in the literature at the moment. Therefore, the purpose of this study is to describe why performance in a linear acceleration task is affected by LBS. Fifteen male athletes were analysed using full-body motion analysis combined with ground reaction force (GRF) measurements during the first step of a full effort 5 m sprint in a low stiffness baseline (BL), medium stiffness (MS) and high stiffness (HS) condition. A significant reduction in acceleration performance (−6.3%) was found in the HS condition compared to BL. Changes in acceleration performance in MS and HS were related to altered contact times, ground force application and overall body orientation, but not to alterations in energy absorption at the metatarsal phalangeal (MTP) joint. A gearing function of LBS was evident from increased MTP and ankle joint GRF lever arms, which might offer a potential to improve the effectiveness of horizontal force application. Nonetheless, athletes in this study were not using this potential to improve acceleration performance, possibly due to missing strength capacities. The results of this study indicate that high LBS might lead to reduced acceleration performance in athletes lacking the capacities to make use of the gearing function of footwear LBS. Footwear studies need to address the interrelationship between LBS, individual strength capacities, average ground force application and its effectiveness during acceleration tasks in the future.
... Many modifications can be made to the shoe-surface interface to influence footwear traction. These modifications may be shoe outsole pattern and outsole material (Andreasson et al. 1986, Schlaepfer et al. 1983, Nigg and Yeadon 1987, Severn et al. 2010, Wannop and Worobets 2013), shoe cleating (Villwock et al. 2009, Wannop et al. 2009, 2010, Severn et al. 2010, Sterzing et al. 2010), and also sport surface material (Nigg and Yeadon 1987, Schlaepfer et al. 1983, Severn et al. 2011, Villwock et al. ...
... ). While it has been shown that increasing footwear traction can lead to an increase in performance (Wannop and Worobets 2013), what is usually not considered when moving from one surface to another is the difference in the surface compliance. Compliance is defined as the inverse of stiffness, or the amount a material will deform when placed under a given force. ...
Article
Purpose: To determine how shoe-surface interaction, specifically traction and compliance, affects performance and biomechanics of soccer-related movements. Methods: Third generation artificial turf was installed in the laboratory to allow for kinetic and kinematic data collection both on the turf and on a laboratory surface (Pulastic sports surface). Twelve male athletes performed five 5 m sprint accelerations and five 180 sprint turns in three different shoe-surface conditions (indoor soccer shoe on the laboratory surface, indoor soccer shoe on the turf surface, soccer cleat on turf surface). Comparisons between the indoor shoe across surfaces indicated compliance effects and comparisons between the cleat and indoor shoe on turf indicated traction effects. Results: Performance increased for the sprint acceleration in the indoor shoe on the turf compared to the laboratory (1.04 s vs. 1.08 s); however, no further increase in acceleration performance occurred with the soccer cleat. For the turn movement, no change in performance occurred comparing the indoor shoe across surfaces however an increase in turn performance was seen when using the soccer cleat on turf compared to the indoor shoe (2.67 s vs. 2.56 s). The cleat had both increased utilised translational and rotational traction compared to the indoor shoe on turf for the turn movement. The cleat also resulted in increased ankle eversion moments as well as increased knee abduction and external rotation moments compared to the indoor shoe on the turf surface for the turn movement. Conclusion: Both compliance and traction shoe-surface characteristics affect performance; however, the effects of the different characteristics are different depending on the movement type.
... Shoe designs and modifications, particularly those concerning the midsole structure, are anticipated to lower movement-related forces. Customized designs to facilitate stiffer bending properties in the shoe forefoot [5] or the addition of a stiff thermoplastic polyurethane (TPU) insert between the midsole and outsole of the shoe [6] have effectively enhanced the speed of sidestep movements. Shoe inserts are also often added to regular footwear to shield the foot from possible harmful ground impacts [7]. ...
Article
Shoe design features and mechanical properties are crucial to human locomotion. This study investigated the effects of adjustable shoe sole configuration on the stiffness behavior of shoes under cyclic torsional loading to mimic real-world cutting effects. Three shoe conditions were examined: (i) control shoes (CS) featuring adjustable air cushion shoe soles, (ii) midpart-altered shoes (MAS), and (iii) forepart-altered shoes (FAS), both modified the CS using adjustable elastomeric spacers in sole constructions. Shoes were secured in a specially designed fixture in a material testing machine and subjected to repeated torsional loading–unloading with angular displacements of 0–30° for inversion and eversion motion at an angular velocity of 1°/s. A reliability test validated the experimental method for inversion TS, revealing good intra-session reliability (ICC (3, 1) = 0.71) and excellent inter-session reliability (ICC (3, k) = 0.87). Inversion TS showed a 35.38% increase for the MAS and a 6.15% increase for the FAS compared to the CS. Likewise, eversion TS increased by 29.82% for the MAS and 14.04% for the FAS compared to the CS. These results indicate that altering sole construction with adjustable spacers improved TS and might have the potential to lower the risk of ankle injuries during cutting. It can be inferred that shoes with greater TS may require less mechanical energy to stabilize the foot–ankle structure and that MAS might be a suitable option for sports. The MAS exhibited the highest TS, with values of 0.088 Nm/° during inversion and 0.074 Nm/° during eversion movements, compared to the CS and FAS. This suggests that components of the midpart sole region have a greater impact on TS, and changes in midpart sole construction could have a greater effect on TS characteristics. The findings underscore the importance of the midpart sole region over the forepart. The adjustment of midpart sole configurations had a higher effect on the shoe’s torsional stiffness behavior, which might be important for enhancing performance during cutting movements in sports.
... Overall, the most frequently executed movement was translational movement, with 82.48% of total occurrence. This result supports the previous findings and confirms the importance of translational or linear movements of athletes in futsal [10], as well as in other sports such as soccer, handball, volleyball, and basketball [32][33][34]. We also revealed that of the many translational movements, the majority was low traction demand (58%), in which forward and sideway translation were most utilized (occurrence of 26.52% and 14.36%, respectively. ...
Article
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Purpose This study aimed to classify typical futsal movement patterns while in ball possession and clarify the effect of tournament stages on these movement profiles. Methods A total of 5647 movements in possession of a ball during 8 international futsal matches were analysed. These matches consisted of 4 group stages, and there were 4 knockout stage matches (2 semi-finals, a third-place play-off, and the final). On the basis of the observation of 2 experienced analysts, 8 translational and rotational movement indicators were established: forward translation, backward translation, sideway translation, and slow rotation (defined as the low traction demand movement), and side-cut, u-cut, fast rotation, and sudden stop (defined as the high traction demand movement). Results The overall results highlighted that 82.48% of the analysed movements were translational movements [top-three highest movements proportion: (1) forward translation: 26.52%, (2) side-cut: 15.76%, and (3) sideway translation: 14.36%]. Furthermore, there was a significantly higher frequency of translational movements among players during knockout stage matches ( p = 0.03), suggesting that these translational movements form the foundation aspects in maintaining ball possession. Also, a significantly higher occurrence was observed for 2 high traction demand movements [u-cut ( p = 0.02) and fast rotation ( p < 0.0001)] during knockout stage matches compared with group stage matches. Conclusions High traction demand translational movements related to changes of direction were significantly influenced by the stages of the tournament in highly competitive futsal matches.
... The nature of side cutting maneuvers is influenced by various factors, such as run up 9 , foot placement, 10 weight acceptance, 11,12 change of direction, 13 and push off characteristics. 1,2 Biomechanical studies usually focus on the ground contact phase, which can be divided into two main parts: weight acceptance and push off. 12,14 A study on maximum performance 45° side cutting showed that peak plantar pressure of the heel and midfoot regions occurred during the beginning of ground contact during weight acceptance (within @ 30% contact time), while peak pressure at the forefoot and toe regions occurred later, during the push off (@ 50 to 70% contact time). ...
Article
Full-text available
This study examined the influence of basketball shoe midsole inserts with different forefoot and rearfoot rebound properties on biomechanical loading and subjective perception during a side-cutting maneuver. Eleven male basketball players executed side cutting in four shoe conditions mechanically characterized for their rearfoot/forefoot rebound: compliant/compliant, springy/springy, compliant/springy, and springy/compliant. Lower extremity kinetics and kinematics (normalized to body mass), as well as subjective perception, were measured. During the weight-acceptance phase, there were no differences between shoes in all biomechanical variables, except a slightly greater ankle range of motion (1.2° greater than the other three shoes) in the frontal plane for shoe compliant/springy. During the push-off phase, shoe springy/springy led to a greater ankle plantarflexion moment (1.21 Nm/kg greater than the other three shoes, p < 0.001) and knee internal rotation moment (0.09 Nm/kg greater than the other three shoes, p = 0.012), while shoe compliant/springy resulted in a greater ankle range of motion in the frontal plane (1.4° greater than the other three shoes, p < 0.001). Perception data showed no statistically significant difference among any shoes. In conclusion, springy inserts of basketball shoe midsoles induced a biomechanical loading effect. Perception of players being unaffected indicates the importance of biomechanical evaluation to examine the effects of the given shoe modifications during side cutting.
... Despite the risk of a type-II error, the authors are confident in the value and significance of this study's findings as they are congruent with results from previous experiments. Wannop 7 did not find significant effects of basketball shoe weight on jump or shuffle performance of blinded athletes. Similarly, a shoe weight increase of 35% did not affect performance of blinded soccer players during cutting and sprinting drills 14 . ...
Article
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The aim of this study was to determine the effect of shoe mass on performance in basketball specific movements and how this effect changes if an athlete is aware or not of the shoe's mass relative to other shoes. In an experimental design, 22 male participants were assigned to two groups. In the "aware" group, differences in the mass of the shoes were disclosed, while participants in the other group were blinded to the mass of shoes. For both groups lateral shuffle-cut and vertical-jump performances were quantified in 3 different basketball shoe conditions (light = 352±18.4g; medium = 510±17g; heavy = 637±17.7g). A mixed ANOVA compared mean shuffle-cut and vertical-jump performances across shoes and groups. For blinded participants, perceived shoe weight ratings were collected and compared across shoe conditions using a Friedman two-way ANOVA. In the aware group, performance in the light shoes was significantly increased by 2% (vertical-jump: 2 %, p<0.001; shuffle-cut: 2.1 %, p<0.001) compared to the heavy shoes. In the blind group, participants were unable to perceive the shoe weight variation between conditions and there were no significant differences in vertical-jump and shuffle-cut performance across shoes. Differences in performance of the aware participants were most likely due to psychological effects such as positive and negative expectancies towards the light and heavy shoes, respectively. These results underline the importance for coaches and shoe manufacturers to communicate the performance enhancing benefits of products or other interventions to the athletes to optimize the performance outcome.
Article
The focus of this study was to investigate the effects that different basketball shoe outsole tread patterns have on the amount of slip and therefore the performance of the individual while undergoing normal basketball transitions. Tread grooves and patterns must exist on the outsole of a basketball shoe to account for the chances of contamination and for the practical durability of the shoes. With the existence of so many basketball shoes with varying tread patterns and characteristics it presents the question of whether or not varying patterns affect traction, slip, and athletic performance. This study evaluated the amount of slips of two pairs of basketball shoes with human participants running basketball drills on a hardwood basketball floor at Wartburg College. The results indicated that one shoe with a more unique tread pattern exhibited fewer slips and severe slips, especially when considering lateral movements, than the shoe with a tread pattern seen more often in shoes available on the market today.
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Lighter shoes have been shown to improve running economy; however this same phenomenon has not been investigated in basketball shoes. The purpose of this study was to investigate the physiological effects of basketball shoes of different masses during an on-court, game like scenario. Twelve male basketball players participated in this study. One shoe that was modified to have three different masses (Light, Medium, and Heavy) was evaluated in this study. Subjects completed a basketball-specific 20 minute field-based work protocol (Basketball-20) in each shoe on three different days while five physiological variables of interest were collected. The light shoe condition resulted in significantly lower oxygen consumption, ventilation, and rate of energy expenditure than the medium and heavy conditions.
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The aim of this study was to determine whether increasing the stiffness of the shoe midsole supporting the metatarsophalangeal (MTP) joint could induce a better jumping and lateral cutting movement performance. Twelve young team-sports players used two different shoe models (commercialized), with different sole bending stiffnesses. Two tests were performed: a multi-directional (Multi-D) sprint test including rapid lateral braking and cutting movements, and a fatigue test including drop jumps (DJs) and countermovement jumps (CMJs) in pre- and post-fatigue conditions. A significant (p< 0.05) improvement was observed in the Multi-D test times with the stiffer midsole. Further, in fatigued conditions, the group with the stiffer midsole shoe showed a non-significant 9 per cent performance decrease in CMJs, while this decrease was higher and significant (16.1 per cent; p<0.05) for the compliant midsole group. Compared with the stiffer midsole, the compliant midsole yielded a significant decrease in the jump performance, highlighting the fact that a higher MTP midsole stiffness helped subjects to limit the effects of fatigue on jumping performance. Therefore, a higher midsole MTP stiffness is associated with better performance in indoor-sport-specific movements including fatigued conditions, which could be explained by a preserved dynamic interaction with the ground in these specific sport situations.
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Soccer shoes in general but especially their outsoles are important for running and consequently playing performance. This article aims to quantify running performance and perception of running performance due to type of footwear and surface condition by use of Functional Traction Courses (FTC). Soccer players were required to run through slalom and acceleration courses as fast as possible providing running time and perception of running time variables due to wearing different soccer footwear. A series of eight single studies featuring different types of soccer footwear and different surfaces was conducted. The influence of footwear (subject Means and SD) was analyzed by Repeated Measures ANOVA, followed by post-hoc t-tests when appropriate. Slalom running times were considerably affected by altered shoe/surface interface conditions, whereas acceleration running times were affected only to lesser extent. Running time perception of athletes generally reflected actual running performance. Running performance differed about 3% when altering stud type or stud geometry. Thus, players benefit by the appropriate choice of footwear for a given surface. Complete elimination of studs resulted in a running time difference of 26% compared to normal condition. Surface conditions may be responsible for up to 20% of performance differences. It is recommended to include FTC testing in the evaluation of soccer footwear to get an idea of potential running performance benefits for players.
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The purpose of this study was to evaluate the traction characteristics of four different stud configurations on Fédération Internationale de Football Association (FIFA) 2-Star, third-generation artificial soccer turf. The investigated stud configurations were hard ground design, firm ground design, soft ground design, and an experimental prototype. The concept of this study combines performance, perception, biomechanical, and mechanical testing procedures. Twenty-five soccer players took part in the different testing procedures. Variables of this study were: running times, subjective rankings/ratings, ground reaction forces, and mechanical traction properties. Statistical discrimination between the four stud configurations was shown for performance, perception, and biomechanical testing (p < 0.05). Unsuited stud configurations for playing on artificial turf are characterized by less plain distributed and pronounced studs.
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ASTM F2333 is a test method for quantifying traction characteristics between an athletic shoe and a sports surface. This standard calls for normal loads of 500-3000 N to be applied between a footform and a playing surface. To assess the effect of varying the normal load on the traction coefficients between cleated athletic shoes and artificial turf surfaces, a new testing device was developed and used to collect traction data. Four different models of cleated athletic shoes were tested on FieldTurf at normal loads ranging from 222 N to 1776 N. Static, dynamic, and peak traction coefficient values were calculated for each condition. There was a significant difference in the slope of the load versus traction coefficient curve for loads below and above 888 N for all three variables measured. No significant differences in traction characteristics were found between shoes for loads below 888 N. Significant differences between the shoes were seen with loads above 888 N. However, buckling and potential permanent damage to the turf surface was seen at loads of 1776 N. The results suggest that traction data obtained on FieldTurf at loads below one body weight are not sensitive to different shoe designs. Therefore, the measurement of traction between cleated shoes and FieldTurf should be conducted at a load of at least 888 N which is, in part, consistent with the default normal load of 1000 N in ASTM F2333. However, a normal force of 3000 N defined in the standard for studying stopping may not be feasible without permanently damaging the turf surface.
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The aim of this study was to assess the influence of footwear with increased ankle support on ankle kinematics and on impact loads during landing from a vertical jump using high-speed cinematography, dynamometry and accelerometry in a series of tests in which a rebound action was simulated. To analyse the effect of this increased support on motor performance, two performance tests were designed: a vertical jump test and an obstacle course running test. Two prototype shoes with identical soles but different uppers were used. The first was designed to provide greater ankle support, with such features as a high top, heel counters and a rearfoot lacing system. The second prototype was a less supporting shoe, with low top and no heel counter or any other feature for support. In the shock attenuation test, the use of high-support shoes resulted in higher forefoot impact forces and higher shock transmission to the head, but showed lower shock transmission to the tibia. The use of high support shoes resulted in lower ranges of eversion and higher ranges of inversion of the ankle on landing. In the motor performance tests, the high-support shoes reduced the height jumped and increased the time to complete the running course relative to the low-support shoes. We conclude that increased ankle support reduces ankle eversion range but increases shock transmission, and reduces both jumping and running performance.
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The higher oxygen consumption reported when shod running is compared to barefoot running has been attributed to the additional mass of the shoe. However, it has been reported that wearing shoes also modified the running pattern. The aim of this study was to distinguish the mass and shoe effects on the mechanics and energetics when shod running. Twelve trained subjects ran on a 3-D treadmill ergometer at 3.61 m . s (-1) in six conditions: barefoot, using ultra thin diving socks unloaded, loaded with 150 g, loaded with 350 g, and two shoe conditions, one weighing 150 g and another 350 g. The results show that there was a significant mass effect but no shoe effect for oxygen consumption. Stride frequency, anterior-posterior impulse, vertical stiffness, leg stiffness, and mechanical work were significantly higher in barefoot condition compared to shod. Net efficiency, which has metabolic and mechanical components, decreased in the shod condition. The mechanical modifications of running showed that the main role of the shoe was to attenuate the foot-ground impact by adding damping material. However, these changes may lead to a decrease of the storage and restitution of elastic energy capacity which could explain the lower net efficiency reported in shod running.
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It has been demonstrated that, by varying the mechanical properties of footwear, the sprinting performance can be improved. It has been hypothesized that, for maximal performance, tuning the shoe stiffness to the requirements of the athlete is necessary. The aim of this study was to investigate the feasibility of using sprint shoes constructed with selective-laser-sintered Nylon 12 sole units for sprint-related jump tasks and to examine whether adaptations to the mechanical properties of the footwear were sufficient to elicit changes to lower-limb dynamics during athletic performance. An internationally competitive sprinter completed sprint-related jump metrics in various selective-laser-sintered shoes with bending stiffnesses of 9 N, 24.5 N, and 38 N in flexion and 7.4 N, 14.7 N, and 26.1 N in extension. The participant performed best in the medium-stiffness shoe for squat jumps and the maximum-stiffness shoe for bounce drop jumps. This investigation has demonstrated that selective laser sintering can produce high-integrity footwear with markedly different mechanical properties. Such footwear, coupled with an appropriate test method, has been shown to be suitable for investigating the relationship between lower-limb dynamics and shoe stiffness.
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The primary kinematic factors relating to sprinting performance may be influenced by the mechanical properties of the footwear worn. It was hypothesized that, compared with the barefoot condition, sprint spikes would influence sole angle to the ground, and metatarsophalangeal joint (MPJ) extension and flexion. High-speed video recording was used to analyse key kinematic variables of the foot segments and the MPJ in barefoot and shod running conditions. The stance phases of four sprinters (two male) were captured in the blocks, at 10 m and at 50 m into a maximal effort sprint. Angular range and angular velocity during MPJ flexion at 10 m and 50 m were reduced significantly when wearing sprint spikes. The mean angular range at 10 m was reduced by 11°, 13°, and 5° for the initial flexion phase, the extension phase, and the final phase of flexion respectively. This effect was larger during ground contact at 10 m versus 50 m. Sole angle to the ground at take-off was lower in the sprint spike shod condition than in the barefoot condition. Performance-related parameters such as degree of MPJ extension, MPJ extension velocity, and sole angle to the ground are influenced by sprint spikes when compared with the barefoot condition.
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The purpose of this study was to investigate the relationship between mechanically available footwear traction and performance in top-speed curved sprint running and maximum effort linear acceleration. Based on results from previous studies, it was hypothesized that performance would increase as available traction increased but only to a point after which performance would plateau and further increases in available traction would not affect performance. The goal of this study was to identify such critical traction values. Thirty-two recreational athletes performed maximum effort 2.3 m radius curve sprints and linear accelerations from a standing start using four identical mid-cut basketball shoes differing only in outsole traction. Available traction was modified by manipulating the outsole material. The traction coefficients of the test shoes, quantified with a portable traction tester on the actual test surface, were 0.26, 0.54, 0.82 and 1.13. Ground reaction forces and three-dimensional kinematics were quantified during the tests. Greater amounts of traction (both peak and average) were utilized as the mechanically available traction increased. Increases in available traction from 0.26 to 0.54 to 0.82 provided systematic performance advantages for both curved sprinting and linear acceleration. However, no further performance enhancements were detected when the available traction increased beyond 0.82. Increases in the use of available traction beyond a threshold of 0.82 were reflected in the peak but not the average utilized traction or overall ground reaction impulse generation.
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Primary objective: To determine the range of translational and rotational traction that exists in cleated footwear of athletes, on the surface of play in Canadian high school football.Research design: Field study.Methods and procedures: The shoes of 106 athletes were tested on the field of play using a portable robotic testing machine. The machine measured translational and rotational traction on all shoes. Shoes were compared based on their shape, wear and cleat arrangement; fin, edge, stud.Main outcome and results: Translational and rotational traction ranged from 0.49 to 1.01 and 15.1 to 57.2 Nm, respectively. Fin shoes had significantly lower rotational traction compared to both the edge and stud shoe. Wear resulted in large variability of the cleated traction.Conclusions: The influence of wear has been shown to affect footwear traction, and must be taken into account. Therefore more accurate estimates of traction may occur when testing is completed using players’ actual footwear.
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An increase in traction between the shoe and a playing surface can result in increased forces to be absorbed by the structures of the lower extremity. Alternately, decreased traction causes impaired performance. We hypothesized that changes in the coefficient of friction (CoF) will affect subjective and objective measures of performance for an agility maneuver. Thirty subjects were asked to perform a functional agility maneuver under CoF conditions from 0.3 to 0.7. Subjects performed this agility maneuver over a force plate and were asked to complete a questionnaire evaluating their ability to perform the task under various CoF conditions. Time to complete the task decreased as CoF increased (from 3.1 +/- 0.6 s at CoF 0.3 to 2.6 +/- 0.5 s at CoF 0.5). Peak force, CoF max force plate, and subjective score all increased as CoF increased up to 0.5. CoF of 0.5 or above did not significantly change the subject's ability to perform the cutting maneuver either subjectively or objectively. The CoF of 0.5 was deemed adequate to complete the task for this study. Values above CoF 0.5 did not lead to better performance. More studies are needed to build on these findings to establish criteria on safe shoe-surface interactions in athletic practice and play.
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The aim of this study was to compare ankle and knee joint moments observed when playing on sport surfaces that slide slightly relative to the ground with the moments observed when playing on conventional sport surfaces. Three-dimensional resultant internal joint moments and kinematic characteristics of the lower extremity were quantified for 21 university basketball players when performing v-cut and side-shuffle tasks on three types of sliding surface (interlocking tiles) and on two types of conventional surface (maple wood and rolled vinyl). Translational and rotational friction between the five test surfaces and a test shoe were also quantified. The five sport surfaces moved horizontally between 0.2 and 1.6 mm during the landing phase of the two tasks. The medio-lateral ground reaction forces were lowest for the surfaces with the highest horizontal movement. Resultant ankle joint moments were lower and resultant knee moments were higher on the sliding surfaces than the conventional surfaces. Sport surfaces that allow a few millimetres of horizontal movement during ground contact may reduce joint loading at the ankle joint, but increase joint loading at the knee joint, when compared with conventional sport surfaces, and thus may influence the prevalence of knee injuries.
Article
The purposes of this investigation were to determine the effects of outsole composition and hardness, playing surfaces and player weight on the dynamic torque, traction forces and static drag developed at the shoe-surface interface. Basketball shoes of polyurethane and elastomer outsoles, each of three different hardnesses, were tested on clean and dusty hardwood floor samples, and on a sample of an artificial gymnasium flooring. The tests were conducted using a laboratory apparatus which included a player leg assembly with simulation of two player weights. Dynamic torque, traction forces from side and rear impacts and static drag were measured at the shoe surface interface. The results indicated that in basketball the magnitude of the resistance forces and torques are influenced by the outsole material and outsole hardness of the shoes, the playing surface and player weights.
Article
Stabilization of the ankle joint is used as a deterrent to injury, however, insufficient or excessive ankle control can cause negative effects. This study determined the effects of systematic changes in ankle and subtalar joint stabilization on performance through an obstacle course. Data were collected on six subjects as they completed two test procedures. Ankle range of motion in the sagittal and frontal planes was determined using a modified Inman apparatus. Completion time through an obstacle course, set up on a basketball court, was used as a measure of performance. High-top basketball shoes were constructed with pockets which allowed strips of plastic (stiffeners) to be positioned just anterior and posterior to the medial and lateral malleoli. Four shoe conditions were used including the shoe with no stiffeners. Significant differences (P less than 0.05) in eversion, flexion, and inversion were found between the shoe conditions. A general trend of decreased range of motion with increased restriction was observed. Significant differences (P less than 0.05) in performance were found between the shoe conditions, with a general trend of increased times with increased restriction. These results indicate that systematic changes in the range of motion of the ankle and subtalar joints can measurably affect performance.
Article
The minimum translational traction requirements of outsoles for shoes used for walking, running, and activities involving lateral movements are presented. Since it will be shown that the classical friction relationships described by Coulomb do not always apply to the elastomeric materials used in modern day athletic footwear, empirical measures of the traction characteristics of candidate materials and designs must be made. A physical traction testing device has been developed to make measurements of the traction characteristics of shoe outsoles will be described. This device quantifies both translational and rotational traction characteristics. Examples of factors affecting both of these variables are presented. Combining a knowledge of the traction characteristics of materials and designs and the factors influencing traction with knowledge of the traction requirements of different activities permits the matching of appropriate outsoles to shoes used for specific activities.
Article
Sideward cutting movements occur frequently in sports activities, such as basketball, soccer, and tennis. These activities show a high incidence of injuries to the lateral aspect of the ankle. Consequently, the lateral stability of sport shoes seems important. The purpose of this study was to show the effect of different shoe sole properties (hardness, thickness, torsional stiffness) and designs on the lateral stability during sideward cutting movements. A film analysis was conducted including 12 subjects performing a cutting movement barefoot and with five different pairs of shoes each filmed in the frontal plane. A standard film analysis was conducted; for the statistical analysis, various parameters such as the range of motion in inversion and the angular velocity of the rearfoot were used. The results showed a large difference between the barefoot and shod conditions with respect to the lateral stability. Two shoes performed significantly better (P < 0.05) than the others with a decreased inversion movement and less slipping inside the shoe. The two shoes differed mainly in the shoe sole design (hollow inner core) and the upper (high-cut). It is concluded that lateral stability may be improved by altering the properties and design of the shoe sole as well as the upper.
Article
A substantial amount of rotational energy is lost at the metatarsophalangeal joint during running and jumping. We hypothesized that the lost energy could be decreased by increasing the bending stiffness of shoe midsoles. The purposes of this investigation were to determine the influence of stiff shoe midsoles on changes in lower extremity joint power during running and jumping and to determine the influence of stiff shoe midsoles on vertical jump performance. Carbon fiber plates were inserted into shoe midsoles and data were collected on five subjects during running and vertical jumping. The data showed that energy generation and absorption at each of the ankle, knee, and hip joints was not influenced by the stiffness of the shoe midsole. The stiff shoes with the carbon fiber plates did not increase the amount of energy stored and reused at the metatarsophalangeal joint; however, they reduced the amount of energy lost at this joint during both running and jumping. Vertical jump height was significantly higher (average, 1.7 cm for a group of 25 subjects) while wearing the stiff shoes. Increasing the bending stiffness of the metatarsophalangeal joint reduced the amount of energy lost at that joint and resulted in a corresponding improvement of performance.
Article
To investigate the external loads applied to the knee joint during dynamic cutting tasks and assess the potential for ligament loading. A 50-Hz VICON motion analysis system was used to determine the lower limb kinematics of 11 healthy male subjects during running, sidestepping, and crossover cut. A kinematic model was used in conjunction with force place data to calculate the three-dimensional loads at the knee joint during stance phase. External flexion/extension loads at the knee joint were similar across tasks; however, the varus/valgus and internal/external rotation moments applied to the knee during sidestepping and crossover cutting were considerably larger than those measured during normal running (P < 0.05). Sidestepping tasks elicited combined loads of flexion, valgus, and internal rotation, whereas crossover cutting tasks elicited combined loads of flexion, varus, and external rotation. Compared with running, the potential for increased ligament loading during sidestepping and crossover cutting maneuvers is a result of the large increase in varus/valgus and internal/external rotation moments rather than any change in the external flexion moment. The combined external moments applied to the knee joint during stance phase of the cutting tasks are believed to place the ACL and collateral ligaments at risk of injury, particularly at knee flexion angles between 0 degrees and 40 degrees, if appropriate muscle activation strategies are not used to counter these moments.
Article
The purposes of this investigation were to determine if increasing the bending stiffness of sprint shoes increases sprinting performance and to determine whether simple anthropometric factors can be used to predict shoe bending stiffness for optimal performance. Thirty-four athletes were tested using four different shoe conditions--a standard condition consisting of their currently used footwear and three conditions where the bending stiffness was increased systematically. The sprinters performed maximal effort 40 m sprints and their sprint times were recorded from 20 to 40 m. On average, increasing the shoe bending stiffness increased sprint performance. The stiffness each athlete required for his or her maximal performance was subject specific but was not related to subject mass, height, shoe size or skill level. It is speculated that individual differences in the force-length and force-velocity relationships of the calf muscles may influence the appropriate shoe stiffness for each athlete to obtain their maximal performance.
Article
Various features of the design of running shoes have been known to affect the performance and safety of athletes. The performance related effects of shoe design on traction and on the economy of locomotion are reviewed in this paper. Traction measurements in various types of running shoes and on various surfaces appear adequate for all but running on wet asphalt roads. Future designs should improve traction for those conditions. Effects on the economy of locomotion as small as 1% can be determined using conventional oxygen uptake measurements. The effect of carrying extra weight on the foot during running has been measured at 1% per 100 g per foot. The cost of carrying similar weights is much lower for walking or for running when the weight is carried nearer the body's centre of mass. Cushioning and other features of shoe design besides weight have been shown to have significant effects on the economy of locomotion. Optimum designs for maximising running performance should provide sufficient traction, minimal weight and maximum cushioning.
Article
This study characterizes the stiffness of the human forefoot during running. The forefoot stiffness, defined as the ratio of ground reaction moment to angular deflection of the metatarsophalangeal joint, is measured for subjects running barefoot. The joint deflection is obtained from video data, while the ground reaction moment is obtained from force plate and video data. The experiments show that during push-off, the forefoot stiffness rises sharply and then decreases steadily, showing that the forefoot behaves not as a simple spring, but rather as an active mechanism that exhibits a highly time-dependent stiffness. The forefoot stiffness is compared with the bending stiffness of running shoes. For each of four shoes tested, the shoe stiffness is relatively constant and generally much lower than the mean human forefoot stiffness. Since forefoot stiffness and shoe bending stiffness act in parallel (i.e., are additive), the total forefoot stiffness of the shod foot is dominated by that of the human foot.
Article
Synthetic playing surfaces with rubber or sand infill are now used on many athletic fields such as soccer, football and rugby. Although these surfaces may come closer to the mechanical characteristics of a true grass playing surface than the older turf designs, their potential effects on lower extremity biomechanics and related injury rates necessitate further study. The purpose of this study was to examine the effects of two surfaces (natural grass versus turf) on in-shoe foot loading patterns during cutting. Seventeen male football players were tested on a slalom course. An in-shoe pressure distribution measurement insole was used in the right shoe (14 stud, molded cleat) of each athlete. Individual cutting steps were extracted from each slalom trial and peak pressure and relative load calculated in nine distinct plantar regions of the foot. The turf condition had significantly higher peak pressures within the central forefoot (turf: 646.6+/-172.6 kPa, grass: 533.3+/-143.4 kPa, P=0.017) and lesser toes (turf: 429.3+/-200.9 kPa, grass: 348.1+/-119.0 kPa, P=0.043) compared to grass. In contrast, the relative load within the medial forefoot (turf: 27.2+/-5.3%, grass: 30.2+/-6.6%, P=0.031) and lateral midfoot (turf: 3.4+/-1.8%, grass: 4.1+/-2.3%, P=0.029) were higher during the grass condition. No differences between the grass and turf were found in maximal effort sprint times performed prior to the testing trials. This study demonstrates that playing surface significantly affects plantar loading during sport related activities. Further epidemiological investigation is warranted to determine the effects of playing surfaces on sport specific injury mechanisms.
Article
In this study, we evaluated the protective functions of cloth sport shoes, including cushioning and lateral stability. Twelve male students participated in the study (mean +/- s: age 12.7 +/- 0.4 years, mass 40.7 +/- 5.9kg, height 1.50 +/- 0.04m). Cloth sport shoes, running shoes, basketball shoes, crosstraining shoes, and barefoot conditions were investigated in random sequence. Human pendulum and cutting movement tests were used to assess cushioning performance and lateral stability, respectively. For cushioning, the running shoes (2.06 body weight, BW) performed the best, while the cross-training shoes (2.30 BW) and the basketball shoes (2.37 BW) both performed better than the cloth sport shoes (2.55 BW) and going barefoot (2.63 BW). For the lateral stability test, range of inversion--eversion was found to be from 3.6 to 4.9 degrees, which was far less than that for adult participants (> 20 degrees). No significant differences were found between conditions. All conditions showed prolonged durations from foot-strike to maximum inversion (66-95 ms), which was less vigorous than that for adult participants (< 40 ms) and was unlikely to evoke intrinsic stability failure. In conclusion, the cloth sport shoe showed inferior cushioning capability but the same lateral stability as the other sports shoes for children.
Time-motion analysis and physiological data of elite under-19-year-old basketball players during competition
  • N B Abdelkrim
  • S E Fazaa
  • J E Ati
Abdelkrim, N. B., Fazaa, S. E., & Ati, J. E. (2007). Time-motion analysis and physiological data of elite under-19-year-old basketball players during competition. British Journal of Sports Medicine, 41, 69-75.
Evaluating outsole traction of footwear
  • G A Valiant
Valiant, G. A. (1994). Evaluating outsole traction of footwear. In Proceedings of the Eighth Biennial Conference of the Canadian Society for Biomechanics (pp. 18-24). Calgary: University of Calgary.