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1.
Abstract

The aim of this study was to investigate the effect of using poles on foot–ground interaction during trail running with slopes of varying incline. Ten runners ran on a loop track representative of a trail running field situation with uphill (+9°), level and downhill (?6°) sections at fixed speed (3.2 m.s?1). Experimental conditions included running with (WP) and without (NP) the use of poles for each of the three slopes. Several quantitative and temporal foot–ground interaction parameters were calculated from plantar pressure data measured with a portable device. Using poles induced a decrease in plantar pressure intensity even when the running velocity stayed constant. However, the localisation and the magnitude of this decrease depended on the slope situations. During WP level running, regional analysis of the foot highlighted a decrease of the force time integral (FTI) for absolute (FTIabs; ?12.6%; P<0.05) and relative values (FTIrel; ?14.3%; P<0.05) in the medial forefoot region. FTIabs (?14.2%; P<0.05) and duration of force application (Δt; ?13.5%; P<0.05) also decreased in the medial heel region when WP downhill running. These results support a facilitating effect of pole use for propulsion during level running and for the absorption phase during downhill running.  相似文献   

2.
排球运动员步态支撑期的足底压力特征   总被引：1，自引：0，他引：1  
通过测试得到排球运动员步态中足底压力的主要特征,并比较膝关节损伤运动员与无膝关节损伤运动员的足底压力特征,尝试分析膝关节损伤对足底压力产生的变化,为排球运动员正常步态数据提供可信的参考标准。选取北京体育大学竞技体育学院排球专项学生共48人(26男、22女)作为研究对象。运用FOOTSCAN足底压力分布测量系统和QUALISYS-MCU500红外运动测试系统的6个摄像头采集足底压力及步态基本运动学参数,测量被试者赤足状态下的步态。要求被试者以自己正常的步速行走,左右脚分别测试3次。将足部分为10个解剖分区:第L趾骨(T1)、第2-5趾骨(T2-T5)、第1跖骨(M1)、第2跖骨(M2)、第3跖骨(M3)、第4跖骨(M4)、第5跖骨(M5)、足中部(MF)、足跟内侧(HM)和足跟外侧(HL)。选取各个分区的接触开始时刻、接触结束时刻、最大压强时刻、接触时间作为时间指标。根据足底压力数据,男女排球运动员在步态支撑时期不同阶段的比例分别为:着地阶段(6.2%男,6.4%女)、前足接触阶段(5.5%男,6.6%女)、整足接触阶段(43.44%男,40.4%女)、离地阶段(42.9%男,46.5%女)。膝关节损伤运动员受伤腿足中部足底压强峰值明显低于未受伤腿。  相似文献   

3.
Abstract

Plantar pressure characteristics during fencing movements may provide more specific information about the influence of foot loading on overload injury patterns. Twenty-nine experienced fencers participated in the study. Three fencing-specific movements (lunge, advance, retreat) and normal running were performed with three different shoe models: Ballestra (Nike, USA), Adistar Fencing Lo (Adidas, Germany), and the fencers' own shoes. The Pedar system (Novel, Munich, Germany) was used to collect plantar pressures at 50 Hz. Peak pressures, force–time integrals and contact times for five foot regions were compared between four athletic tasks in the lunge leg and supporting leg. Plantar pressure analysis revealed characteristic pressure distribution patterns for the fencing movements. For the lunge leg, during the lunge and advance movements the heel is predominantly loaded; during retreat, it is the hallux. For the supporting leg, during the lunge and advance movements the forefoot is predominantly loaded; during retreat, it is the hallux. Fencing-specific movements load the plantar surface in a distinct way compared with running. An effective cushioning in the heel and hallux region would help to minimize foot loading during fencing-specific movements.  相似文献   

4.
This study performed an analysis of the push-off forces of elite-short-track speed skaters using a new designed instrumented short-track speed skate with the aim to improve short-track skating performance. Four different skating strokes were distinguished for short-track speed skaters at speed. The strokes differed in stroke time, force level in both normal and lateral directions, and the centre of pressure (COP) on the blade. Within the homogeneous group of male elite speed skaters (N = 6), diversity of execution of the force patterns in the four phases of skating was evident, while skating at the same velocities. The male participants (N = 6) with a better personal record (PR) kept the COP more to the rear of their blades while hanging into the curve (r = 0.82, p < 0.05), leaving the curve (r = 0.86, p < 0.05), and entering the straight (r = 0.76, p < 0.10). Furthermore, the male skaters with a better PR showed a trend of a lower lateral peak force while entering the curve (r = 0.74, p < 0.10). Females showed a trend towards applying higher body weight normalised lateral forces than the males, while skating at imposed lower velocities.  相似文献   

5.
In the current project, we aim to provide speed skaters with real-time feedback on how to improve their skating performance within an individual stroke. The elite skaters and their coaches wish for a system that determines the mechanical power per stroke. The push-off force of the skater is a crucial variable in this power determination. In this study, we present the construction and calibration of a pair of wireless instrumented klapskates that can continuously and synchronously measure this push-off force in both the lateral direction and normal direction of the skate and the centre of pressure of these forces. The skate consists of a newly designed rigid bridge (0.6 kg), embedding two three-dimensional force sensors (Kistler 9602, Kistler Group, Winterthur, Switzerland), which fits between most individual skate shoes and Maple skate blades. The instrumented klapskates were calibrated on a tensile testing machine, where they proved to be unaffected to temperature conditions and accurate up to an RMS of 42 N (SEM = 1 N) in normal and up to an RMS of 27 N (SEM = 1 N) in lateral direction. Furthermore, the centre of pressure of these forces on the blade was determined up to a mean error of 10.1 mm (SD = 6.9 mm). On-ice measurements showed the possibility of recording with both skates simultaneously and synchronously, straights as well as curves. The option to send data wirelessly and real-time to other devices makes it possible to eventually provide skaters and coaches with visual real-time feedback during practice.  相似文献   

6.
The purpose of this paper was to present and evaluate a methodology to determine the contribution of bilateral leg and pole thrusts to forward acceleration of the centre of mass (COM) of cross-country skiers from multi-dimensional ground reaction forces and motion capture data. Nine highly skilled cross-country (XC) skiers performed leg skating and V2-alternate skating (V2A) under constant environmental conditions on snow, while ground reaction forces measured from ski bindings and poles and 3D motion with high-speed cameras were captured. COM acceleration determined from 3D motion analyses served as a reference and was compared to the results of the proposed methodology. The obtained values did not differ during the leg skating push-off, and force–time curves showed high similarity, with similarity coefficients (SC) >0.90 in the push-off and gliding phases. In V2A, leg and pole thrusts were shown to contribute 35.1 and 65.9% to the acceleration of the body, respectively. COM acceleration derived from ground reaction forces alone without considering the COM position overestimated the acceleration compared to data from motion analyses, with a mean difference of 17% (P < 0.05) during leg push-off, although the shapes of force–time curves were similar (SC = 0.93). The proposed methodology was shown to be appropriate for determining the acceleration of XC skiers during leg skating push-off from multi-dimensional ground reaction forces and the COM position. It was demonstrated that both the COM position and ground reaction forces are needed to find the source of acceleration.  相似文献   

7.
Foot loading characteristics during three fencing-specific movements   总被引：1，自引：1，他引：0  
Plantar pressure characteristics during fencing movements may provide more specific information about the influence of foot loading on overload injury patterns. Twenty-nine experienced fencers participated in the study. Three fencing-specific movements (lunge, advance, retreat) and normal running were performed with three different shoe models: Ballestra (Nike, USA), Adistar Fencing Lo (Adidas, Germany), and the fencers' own shoes. The Pedar system (Novel, Munich, Germany) was used to collect plantar pressures at 50 Hz. Peak pressures, force-time integrals and contact times for five foot regions were compared between four athletic tasks in the lunge leg and supporting leg. Plantar pressure analysis revealed characteristic pressure distribution patterns for the fencing movements. For the lunge leg, during the lunge and advance movements the heel is predominantly loaded; during retreat, it is the hallux. For the supporting leg, during the lunge and advance movements the forefoot is predominantly loaded; during retreat, it is the hallux. Fencing-specific movements load the plantar surface in a distinct way compared with running. An effective cushioning in the heel and hallux region would help to minimize foot loading during fencing-specific movements.  相似文献   

8.
优秀速滑运动员弯道蹬冰技术动作结构的模式特征研究   总被引：7，自引：0，他引：7  
建立优秀速滑运动员弯道蹬冰技术动作结构的模式特征 ,对技术动作的诊断和评价具有重要意义。通过运动生物力学方法从三维角度对世界优秀运动员的弯道蹬冰技术进行研究 ,认为 :步长间滑步长度和滑步宽度的组合应遵循 3.6∶1的原则 ;蹬冰过程中人体重心的纵向位移幅度明显大于横向 ,并非传统认识中的横向移动幅度大于纵向 ;优秀速滑运动员运用Clap式冰刀时的展膝程度并非传统认识上的充分伸直 ,而与采用传统冰刀时的展膝程度相似 ;提供了用起蹬条件作为判断和评价运动员蹬冰初始条件的方法 ,并推测了下肢关节的有效蹬伸范围  相似文献   

9.
ABSTRACT

We examined the association between footfall pattern and characteristics of lower limb muscle function and compared lower limb muscle function between forefoot and rearfoot runners. Fifteen rearfoot and 16 forefoot runners were evaluated using ultrasonography of the gastrocnemii and tibialis anterior while strike index and heel strike angle quantified footfall pattern. Higher strike index was associated with lower medial gastrocnemius echo intensity (p = 0.05), lower lateral gastrocnemius echo intensity (p = 0.04), smaller tibialis anterior pennation angle (p = 0.05), and longer lateral gastrocnemius fascicle length (p = 0.04). Larger heel strike angle was associated with smaller medial gastrocnemius cross-sectional area (p = 0.04), shorter lateral gastrocnemius fascicle length (p < 0.01), and lower plantar flexion moment (p < 0.01). Larger plantar flexion moment was associated with lesser medial gastrocnemius echo intensity (p = 0.04), lesser lateral gastrocnemius echo intensity (p = 0.03), and greater lateral gastrocnemius fascicle length (p = 0.02). A smaller plantar flexion moment, larger heel strike angle, lower tibialis anterior echo intensity, larger tibialis anterior pennation angle, and smaller lateral gastrocnemius pennation angle were observed in rearfoot compared to forefoot runners (p < 0.05). Lower limb muscle architecture is associated with footfall pattern and ankle mechanics during running.

Abbreviation: EMG: electromyographic; MG: medial gastrocnemius; LG: lateral gastrocnemius; TA: tibialis anterior; EI: echo intensity; CSA: cross-sectional area; PA: pennation angle; FL: fascicle length; FT: fat thickness  相似文献   

10.
This study aimed (1) to profile the plantar loading characteristics when performing the basketball lay-up in a realistic setting and (2) to determine the number of trials necessary to establish a stable mean for plantar loading variables during the lay-up. Thirteen university male basketball players [age: 23.0 (1.4) years, height: 1.75 (0.05) m, mass: 68.4 (8.6) kg] performed ten successful basketball lay-ups from a stationary position. Plantar loading variables were recorded using the Novel Pedar-X in-shoe system. Loading variables including peak force, peak pressure, and pressure–time integral were extracted from eight foot regions. Performance stability of plantar loading variables during the take-off and landing steps were assessed using the sequential averaging technique and intra-class correlation coefficient (ICC). High plantar loadings were experienced at the heel during the take-off steps, and both the heel and forefoot regions upon landing. The sequential estimation technique revealed a five–eight trial range to achieve a stable mean across all plantar loading variables, whereas ICC analysis was insensitive to inter-trial differences of repeated lay-up performances. Future studies and performance evaluation protocols on plantar loading during basketball lay-ups should include at least eight trials to ensure that the measurements obtained are sufficiently stable.  相似文献   

11.
ABSTRACT

Previous research suggests that landing mechanics may be affected by the mechanics of the preceding jump take-off. The purpose of the present study was to investigate whether jump take-off mechanics influence the subsequent landing mechanics. Female volleyball (n = 17) and ice hockey (n = 19) players performed maximal vertical jumps with forefoot and heel take-off strategies. During forefoot and heel jumps, participants were instructed to shift their weight to their forefoot or heel, respectively, and push through this portion of the foot throughout the jump. Jump mechanics were examined using 3D motion analysis, where lower extremity net joint moment (NJM) work, NJM, and segment angles were compared between forefoot and heel jumps using multivariate ANOVA. During jump take-off, participants performed more positive ankle plantar flexor and knee extensor NJM work in forefoot compared to heel jumps (P < 0.05). From initial foot contact to foot flat, participants performed more negative ankle plantar flexor and hip extensor NJM work during heel compared to forefoot jumps (P < 0.05). The present results demonstrate that using a heel take-off strategy results in a different distribution of lower extremity NJM work and NJM during landing compared to landings following forefoot jumps.  相似文献   

12.
Excessive foot pronation during gait is a risk factor in medial tibial stress syndrome (MTSS). Arch-support foot-orthoses are commonly used to manage overpronation, but it is unknown whether it is effective to manage MTSS. The present study investigated the effects of bilateral foot orthoses during running on dynamic foot-pressure distribution patterns in recreational runners with MTSS. Fifty novice (started within the last 4 months) runners diagnosed with MTSS (20.7?±?2.2 years; 71.1?±?8.6?kg; 1.78?±?0.07?m; mean?±?SD) and 50 anthropometrically-matched healthy novice runners (21.9?±?2.4 years; 71.4?±?8.8?kg; 1.73?±?0.07?m) participated in this study. The dynamic foot-pressure distribution during running with and without bilateral arch-support foot-orthoses was measured using pedobarography. MTSS novice runners have more medially directed pressures during the touchdown phase of the forefoot flat (p?=?0.009) and heel off (p?=?0.009), and a lateral pressure distribution during forefoot push-off phase (p?=?0.007) during running than healthy runners. When using the arch-support foot-orthoses the foot-pressure distribution during all phases was not significantly different from that seen in participants without MTSS. These findings indicate that during running the medial shift of foot pressures during the loading response phase and the lateral shift during the propulsion phase of foot roll-over in MTSS are effectively corrected by using arch-support foot-orthoses. The use of such arch-support orthoses may thus be an effective tool to normalize foot-pressure distribution patterns during running, indicating the potential to treat and prevent MTSS in recreational runners.  相似文献   

13.
The forward skating start is a fundamental skill for ice hockey players, yet extremely challenging given the low traction of the ice surface. The technique for maximum skating acceleration of the body is not well understood. The aim of this study was to evaluate kinematic ice hockey skating start movement technique in relation to a skater’s skill level. A 10-camera motion capture system placed on the ice surface recorded “hybrid-V” skate start movement patterns of high and low calibre male ice hockey players (n = 7, 8, respectively). Participants’ lower body kinematics and estimated body centre of mass (CoM) movement during the first four steps were calculated. Both skate groups had similar lower body strength profiles, yet high calibre skaters achieved greater velocity; skating technique differences most likely explained the performance differences between the groups. Unlike over ground sprint start technique, skating starts showed greater concurrent hip abduction, external rotation and extension, presumably for ideal blade-to-ice push-off orientation for propulsion. Initial analysis revealed similar hip, knee and ankle joint gross movement patterns across skaters, however, further scrutiny of the data revealed that high calibre skaters achieved greater vertical CoM acceleration during each step that in turn allowed greater horizontal traction, forward propulsion, lower double-support times and, accordingly, faster starts with higher stride rates.  相似文献   

14.
Abstract

Researchers and clinicians have suggested that overuse injuries to the lower back and lower extremities of figure skaters may be associated with the repeated high impact forces sustained during jump landings. Our primary aim was to compare the vertical ground reaction forces (GRFs) in freestyle figure skaters (n = 26) and non-skaters (n = 18) for the same barefoot single leg landing on a force plate from a 20 cm platform. Compared with non-skaters, skaters exhibited a significantly greater normalised peak GRF (3.50 ± 0.47 × body weight for skaters vs. 3.13 ± 0.45 × body weight for non-skaters), significantly shorter time to peak GRF (81.21 ± 14.01 ms for skaters vs. 93.81 ± 16.49 ms for non-skaters), and significantly longer time to stabilisation (TTS) of the GRF (2.38 ± 0.07 s for skaters vs. 2.22 ± 0.07 s for non-skaters). Skaters also confined their centre of pressure (CoP) to a significantly smaller mediolateral (M–L) (25%) and anterior–posterior (A–P) (40%) range during the landing phase, with the position of the CoP located in the mid to forefoot region. The narrower and more forward position of the CoP in skaters may at least partially explain the greater peak GRF, shorter time to peak, and longer TTS. Training and/or equipment modification serve as potential targets to decrease peak GRF by distributing it over a longer time period. More comprehensive studies including electromyography and motion capture are needed to fully characterise the unique figure skater landing strategy.  相似文献   

15.
短道速度滑冰技术动作分析   总被引：9，自引：0，他引：9  
对运动员的比赛动作进行了运动生物力学分析 ,得知在弯道弧顶 7m长的距离内 ,在高速滑跑的情况下 ,所有运动员都没有完整的单步 ,多数运动员以右单支撑进入该区域 ,以双支撑离开该区域。从身体姿势看 ,蹲屈姿势低 ,上体姿势高。所有运动员都以较低的上体姿势进入弧顶段而以较高姿势离开。身体倾角和蹬冰角越小 ,滑速越快。从弯道弧顶段的平均速度来看 ,女运动员 5 0 0 m的平均速度比 10 0 0 m要快 ,单支撑蹬冰阶段的平均速度比双支撑蹬冰阶段快 ,单支撑阶段的纵向蹬冰是弯道增速的主要动力来源。双支撑阶段的侧蹬冰仍是提高弯道速度的重要手段。双支撑阶段浮腿着冰较早 ,而蹬冰腿迟迟不进行侧蹬冰是导致速度下降的主要原因  相似文献   

16.
承受大赛压力的能力问题已严重影响着我国速滑运动员临场技术水平的正常发挥。温哥华冬奥会日趋临近,中国速度滑冰实现金牌零的突破的愿望越来越强烈,速滑运动员的压力也会随着时间的推移而增加。阐述了速滑运动员的压力表现、成因、调节特点、调节的原则和方法,认为与普通的压力调节不同,速滑运动员的压力调节必须适时地加压和减压,从进行外部施压和提高速滑运动员的内在抗压能力等多方面论述了速度滑冰运动员抗压力能力的培养,以期对速滑运动员积极备战温哥华冬奥会和速滑项目的可持续发展提供借鉴。  相似文献   

17.
The purpose of this study was to determine whether there are differences in the perceived comfort, plantar pressure, and rearfoot motion between laced running shoes and elastic-covered running shoes. Fifteen male amateur runners participated in the study. Each participant was assigned laced running shoes and elastic-covered running shoes for use during the study. The perceived comfort, plantar loading, and rearfoot motion control of each type of shoes during running were recorded. When the laced running shoes and elastic-covered running shoes were compared, the elastic-covered running shoes were given a lower perceived comfort rating in terms of shoe length, width, heel cup fitting, and forefoot cushioning. The elastic-covered running shoes also recorded higher peak plantar pressure in the lateral side of the forefoot, as well as larger maximum rearfoot pronation. Overall, shoelaces can help runners obtain better foot-shoe fit. They increase the perceived comfort, and decrease the maximum pronation and plantar pressure. Moreover, shoelaces may help prevent injury in running by allowing better control of the aforementioned factors.  相似文献   

18.
In this study, we measured the vertical and horizontal take-off forces, plantar pressures and activation patterns of four muscles (vastus lateralis, gluteus maximus, tibialis anterior, gastrocnemius) in 10 ski jumpers in simulated laboratory conditions when wearing either training shoes or ski jumping boots. We found significant differences in vertical ( P ? 0.001), horizontal ( P ? 0.05) and resultant ( P ? 0.001) take-off velocities and vertical force impulse ( P ? 0.01). We found no significant differences in the jumpers' initial take-off positions; however, the jumping boots condition resulted in a smaller displacement in the final position of the following joint angles: ankle angle ( P ? 0.001), knee angle ( P ? 0.001), hip angle ( P ? 0.01) and shank angle relative to the horizontal ( P ? 0.01). This corresponds with less electromyographic activity during take-off in both the gastrocnemius (300 to 200 ms and 200 to 100 ms before take-off) and gluteus maximus (300 to 200 ms and 100 to 0 ms before take-off). During the early take-off in the jumping boots condition, significantly more pressure was recorded under the heel ( P ? 0.001), whereas the forefoot was more highly loaded at the end of the take-off. Differences in take-off velocity (representing the final output of the take-off) can be accounted for in the main by the different use of plantar flexion, emphasizing the role of the knee and hip extensors when wearing jumping boots. We conclude that the stiffness of the structure of the jumping boots may result in a forward shift of pressure, thus limiting the effective vertical force. To avoid this pressure shift, the pattern of movement of simulated take-offs should be carefully controlled, particularly when wearing training shoes.  相似文献   

19.
Little biomechanical research has been conducted recently on hockey skating despite the sport's worldwide appeal. One reason for this lack of biomechanical knowledge stems from the difficulty of collecting data. The lack of accuracy, the disputable realism of treadmills, and the large field of view required are some of the technical challenges that have to be overcome. The main objective of the current study was to improve our knowledge of the joint kinematics during the skating stroke. A second objective was to improve the data collection system we developed and the third was to establish if a kinematic progression exists in the hockey skating stroke similar to that in speed skating. Relative motions at the knee and ankle joints were computed using a joint coordinate system approach. The differences at the knee joints in push-offs indicated that the skating skill was progressively changing with each push-off. The relative stability of the ankle angles can be attributed to the design of the skate boots, which have recently become very rigid. Further research on ice hockey skating is warranted and should include more skaters and investigate the effect various starting strategies and variations in equipment have on skaters' performance.  相似文献   

20.
以上海市蹦床队5名一线男子运动员为研究对象，通过视频与足底压力同步测试的研究方法，对蹦床运动员的预跳和5个基本的技术动作进行测试，研究男子蹦床运动员在完成不同基本技术动作过程中足底压力的分布的特征及足底压力分布的一般规律。为蹦床运动员进行科学训练提供理论依据，为蹦床运动员运动技术诊断提供客观指标。研究结论：运动员完成不同基本技术动作足底压力分布特征规律相同，足底压力合力变化、压强峰值分布和压力中心变化无显著性差异。触网起跳过程双足压力合力呈单峰曲线网面达最低点时双足压力合力最大，双足压力合力最大值可达体重的3.04倍。压强峰值表现为双足第五趾骨区较高。运动员在起网蹬伸阶段双足呈现出压力中心偏移现象，与运动员起跳过程中双足用力不均有关。  相似文献   

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