运动员行军足

1921年Deuschlander首先描述了这种在负荷过重特别是在扁平足基础上长途步行或急行军后发生的跖骨骨折。本病多发生于男性青年。骨折常位于第二或第三跖骨,很少两骨同时受累。其发生的主要原因是足机能疲劳状态下负荷过重的力学因素所致。一个或数个跖骨疏松带发生结构变化和多发性微骨折是病理过程产生的基础。 近年来作者观察到苏联运动员3人发生了行军足,其中男2人,女1人,年龄为     

提踵状态下足纵弓应力分布有限元分析

根据实拍女性提踵状态下第一跖纵弓MRI成像,综合考虑骨、软骨、足底肌、腱膜等各种材料特性,通过Ansys有限元分析软件建模和Novelpedar实测足底压力分布变化值,计算得出提踵步态周期各个阶段的第一跖纵弓应力。发现第一跖骨、楔骨、距舟关节和腱膜等处出现相对较高的应力值,从力学角度解释了由于提踵动作引起的常见足病部位,验证了其产生的原因和所建立分析模型的可靠性。     

青少年男排运动员腕骨形态结构的CT图像分析

为了探讨排球运动对手部骨关节形态结构的影响,分析了青少年男排运动员腕骨CT图像的结构特点。选取省级青年队专业排球运动员9人(排球组),非排球运动员11人(对照组)。用64排螺旋CT对手腕部进行扫描并三维重建,测量各腕骨体积及CT值(骨密度)。结果显示:与对照组各腕骨相比,排球组右手手舟骨和小多角骨,左手手舟骨、大多角骨和小多角骨体积均显著增加(P<0.05);排球组右手三角骨、豌豆骨、大多角骨、钩骨以及左手钩骨CT值明显小于对照组(P<0.05);排球组左手各腕骨体积及CT值与右手相比差异无显著性(P>0.05)。结果说明:排球运动可使青少年男性运动员部分腕骨体积增大,骨密度降低;排球运动员非扣球手腕骨形态结构与扣球手发生相似的改变。     

平足儿童足底压力分析与运动矫治

目的：探讨儿童正常足与扁平足的足底压力差异,为运动矫治提供参考。方法：对13—14岁在较小学生进行足印测量,根据足印足弓空白区宽度将被检者分为正常足、轻度扁平足和重度扁平足,采用足底压力分布测试系统对三组被检者足底压力进行测量。结果：轻度和重度扁平足儿童足掌和足后最的接触面积均小于正常足儿童,P〈0．05;而足弓区接触面积辊度和重度扁平足儿童均大于正常足儿童,P〈0．05。轻度和重度扁平足儿童前掌和足弓所受冲量均大于正常足儿童,而后跟所受冲量则小正常足儿童,P〈0．05。结论：扁平足在着地时压力中心更为密集,其足弓和足掌所受的冲量较大,可通过足趾收展、屈曲练习或足趾抓弹珠、足趾夹铅笔、足背抬沙袋等运动锻炼进行矫治。     

足弓形态与运动关系的研究

足弓形态与运动关系的研究郑岩岚，蔡春华（华南师范大学）１言前人们一直认为良好的足弓是跑跳的基础，高足弓的人比低足弓者在运动中更易发挥水平。然而张月芳对运动员扁平足调查的结果认为：运动员扁平足的发生率高于普通人，并且扁平足者”的运动能力不低于正常足者。...     

普通大学女生扁平足与平衡能力的关系研究

目的研究扁平足对平衡能力的影响,为运动选材提供理论依据。方法选取60名普通大学女生,运用足印法和三线法筛选出扁平足和正常足;再采用神经肌肉控制康复训练与评估系统(HUBER360)分别进行双足和单足平衡能力的测试。结果普通女大学生扁平足的检出率为35%;左右侧扁平足发生率(P>0.05)和正常足与扁平足的平衡能力(P>0.05),差异均不具有显著性。结论女大学生扁平足检出率偏高,对普通大学女生的双足以及单足平衡能力均没有不良影响;扁平足女生应选择合适的鞋子,在长时间步行、站立后应对足弓进行放松,多参加一些高抬腿和弹跳的运动锻炼。     

扁平足综合测定法的X光鉴定分析

随着体育运动的发展,各运动项目都要求运动员具有较高的先天素质,运动员的形态是几大素质中比较重要的一项,因为形态的不足会直接导致运动能力的下降。要想在较低的条件达到较高的运动技术水平,是比较困难的。目前,各运动队在选材中排斥“扁平足的运动员”,认为扁平足对跳跃和持久运动有较大的不良影响,运动中易出现下肢、特別是小腿和足的早期疲劳现象。但是,近来国内有些研究人员做了大量的调查分析,认为运动员有扁平足对运动没有太大的不良影响。这是由于有许多从事跳跃、赛跑运动、并有很高运动年限和运动水平的运动员都相对地     

内翻式落地足跖骨力学反应研究

根据足三维有限元模型探究跖骨在不同角度内翻状态下力学状态变化。研究结果显示内翻态峰值应力集中于第五跖骨基底,体现了落地时前掌跖骨应力分布。该模型大致反映了足部结构在非正常落地时前掌支撑力学功能,并为损伤原理提供一定指导。     

郁闷的足舟骨

虽然足舟骨坚固异常,但对于体重大,从事激烈运动的人来说,足舟骨也是十分脆弱的骨骼,姚明的连续左脚足舟骨应力性骨折已经证明了这点。     

体育锻炼的自我身体监督

在青少年发育过程中，人们往往对脚的发育不够重视，或缺少锻炼，或锻炼强度过大，使发育出现问题，其中扁平足就是青少年生长发育过程中常出现的问题之一。一、扁平足的判断学生赤脚蘸水，在干燥的水泥地面上留下足的印记。前脚掌与后脚掌水的印记断开，可以判断为高足弓；足弓印记连在一起，但没有超过脚的中指连线，属于正常足弓；超过中指连线，即可视为扁平足；如果足的印记前后脚掌通连，并且几乎同宽，即视为平足。平足和扁平足之间以一指间距分为轻度、中度、重度三个级别的扁平足。一般情况下，具有高足弓的学生足的弹性较好，跑跳…     

Foot posture alteration and recovery following a full marathon run

Prolonged running results in lowering of the foot arch and a low arch is associated with subsequent chronic injuries. Foot posture alteration and recovery following a marathon run remain unknown. Therefore, the present study aimed to evaluate foot posture alteration following a full marathon run. The three-dimensional foot posture data of 11 collegiate runners were obtained using an optical foot scanner system before, and immediately, 1 day, 3 days, and 8 days after a full marathon. The navicular height and arch height ratio significantly decreased from before to immediately, 1 day, 3 days, and 8 days after the marathon (navicular height: before, 44.2?±?5.0?mm; immediately after, 39.4?±?5.5?mm; 1 day, 37.7?±?6.2?mm; 3 days, 38.7?±?5.5?mm; 8 days, 37.6?±?5.7?mm; arch height ratio: before, 18.4?±?1.9; immediately after, 16.5?±?2.5; 1 day, 15.7?±?2.5; 3 days, 16.2?±?2.6; 8 days, 15.6?±?2.2, P?, respectively). By contrast, the dorsal height significantly increased from before and immediately after to 1 day after the marathon, and then significantly decreased until 8 days after the marathon (P?). These results indicate that the recovery patterns of the dorsal and navicular heights following a marathon did not coincide; the dorsal height rose temporally at 1 day after and subsequently decreased, but the navicular height decreased throughout the 8-day period after the marathon. More than one week may be necessary for sufficient foot alignment recovery from marathon-induced changes.     

A biomechanical comparison of the topspin and backspin forehand approach shots in tennis

Three‐dimensional (3‐D) high‐speed cinematographic techniques were used to record topspin and backspin forehand approach shots hit down‐the‐line by high‐performance players. The direct linear transformation (DLT) technique was used in the 3‐D space reconstruction from 2‐D images recorded via laterally placed phase‐locked cameras operating at 200 Hz. A Mann‐Whitney U‐test was calculated for the different aspects of the topspin and backspin shots to test for significance (P<0.05).

A significant difference was recorded between topspin and backspin shots in the angle of the racket at the completion of the backswing. The racket was taken 0.48 rad past a line drawn perpendicular to the back fence for topspin trials, but only rotated 0.86 rad from a line parallel to the net in the backspin shot. Maximum racket velocities occurred prior to impact and were significantly higher in topspin (26.5 m s‐¹) compared to backspin (16.6 m s^‐1) trials. This resulted in the topspin trials recording a significantly higher ball velocity compared to backspin trials (27.6 m s^‐1 vs 21.7 m s^‐1). Pre‐impact racket trajectories revealed that in topspin shots the racket moved on an upward path of 0.48 rad while in backspin shots it moved down at an angle of 0.34 rad. In the topspin trials impact occurred significantly further forward of the front foot than in backspin shots (0.26 m vs 0.05 m) while the angle of the racket was the same for both strokes (0.14 rad behind a line parallel to the net). The mean angle of the racket‐face at impact was inclined backwards by 0.11 rad for backspin strokes and rotated forward by 0.13 rad for topspin strokes. Angles of incidence and reflection of the impact between the ball and the court showed that backspin trials had larger angles of incidence and reflection than topspin strokes.     

A descriptive study of step alignment and foot positioning relative to the tee by professional rugby union goal-kickers

This study describes foot positioning during the final two steps of the approach to the ball amongst professional rugby goal-kickers. A 3D optical motion capture system was used to test 15 goal-kickers performing 10 goal-kicks. The distance and direction of each step, as well as individual foot contact positions relative to the tee, were measured. The intra- and inter-subject variability was calculated as well as the correlation (Pearson) between the measurements and participant anthropometrics. Inter-subject variability for the final foot position was lowest (placed 0.03 ± 0.07 m behind and 0.33 ± 0.03 m lateral to the tee) and highest for the penultimate step distance (0.666 ± 0.149 m), performed at an angle of 36.1 ± 8.5° external to the final step. The final step length was 1.523 ± 0.124 m, executed at an external angle of 35.5 ± 7.4° to the target line. The intra-subject variability was very low; distances and angles for the 10 kicks varied per participant by 1.6–3.1 cm and 0.7–1.6°, respectively. The results show that even though the participants had variability in their run-up to the tee, final foot position next to the tee was very similar and consistent. Furthermore, the inter- and intra-subject variability could not be attributed to differences in anthropometry. These findings may be useful as normative reference data for coaching, although further work is required to understand the role of other factors such as approach speed and body alignment.     

Gender differences in foot shape: a study of Chinese young adults

One important extrinsic factor that causes foot deformity and pain in women is footwear. Women's sports shoes are designed as smaller versions of men's shoes. Based on this, the current study aims to identify foot shape in 1,236 Chinese young adult men and 1,085 Chinese young adult women. Three-dimensional foot shape data were collected through video filming. Nineteen foot shape variables were measured, including girth (4 variables), length (4 variables), width (3 variables), height (7 variables), and angle (1 variable). A comparison of foot measures within the range of the common foot length (FL) categories indicates that women showed significantly smaller values of foot measures in width, height, and girth than men. Three foot types were classified, and distributions of different foot shapes within the same FL were found between women and men. Foot width, medial ball length, ball angle, and instep height showed significant differences among foot types in the same FL for both genders. There were differences in the foot shape between Chinese young women and men, which should be considered in the design of Chinese young adults' sports shoes.     

Gender differences in foot shape: a study of Chinese young adults

One important extrinsic factor that causes foot deformity and pain in women is footwear. Women's sports shoes are designed as smaller versions of men's shoes. Based on this, the current study aims to identify foot shape in 1,236 Chinese young adult men and 1,085 Chinese young adult women. Three-dimensional foot shape data were collected through video filming. Nineteen foot shape variables were measured, including girth (4 variables), length (4 variables), width (3 variables), height (7 variables), and angle (1 variable). A comparison of foot measures within the range of the common foot length (FL) categories indicates that women showed significantly smaller values of foot measures in width, height, and girth than men. Three foot types were classified, and distributions of different foot shapes within the same FL were found between women and men. Foot width, medial ball length, ball angle, and instep height showed significant differences among foot types in the same FL for both genders. There were differences in the foot shape between Chinese young women and men, which should be considered in the design of Chinese young adults’ sports shoes.     

Early visual cues associated with a directional place kick in soccer

The purpose of this paper was to establish postural cues in kicking that may be of use to goalkeepers. Eight male soccer players (age 20.5 +/- 1.1 yrs; height 1.78 +/- 0.053 m; mass 75.18 +/- 9.66 kg) performed three types of kick: a low side-foot kick to the left hand corner of the goal, a low side-foot kick straight ahead, and a low instep kick straight ahead. Kicks were recorded by an optoelectronic motion analysis system at 240 Hz. At kicking foot take-off (about 200 ms before ball contact) the variables which were significantly different and could act as cues were support foot progression angle, pelvis rotation, and kicking hip and ankle flexion. The support foot progression angle was considered to be the most valuable of these variables as its angle coincided with the direction of ball projection. The other variables were less clear in their interpretation and so less valuable for a goalkeeper to use for decision making. Cues appearing after support foot contact were thought unlikely to be of value to a goalkeeper in their decision making. These include kicking leg knee flexion angle, and support leg shank and thigh angles.     

Experimental laboratory apparatus to analyze kinematics and 3D kinetics in rowing

In order to quantify internal forces and articular moments, by the inverse dynamics method, specially at lumbar level, an experimental laboratory apparatus to analyze kinematics and 3D kinetics of rowers was developed. It comprised a 3D motion analysis system, a Type C Concept II ergometer, three force-plates, six axes and two miniature mono-dimensional force transducers. The apparatus was designed for each hand, with two miniature transducers integrated into new steel handles to measure the force developed by each hand. Furthermore, the apparatus was also designed for each foot. Two force platforms were placed under two new foot stretchers to measure force and moment developed by each foot. The ergometer also has a sliding seat under which was placed a miniature force platform. A study of the rowing movement of a regional level competition rower demonstrated the relevance of the data. This study was concerned with the 3D kinetics parameters expressed in the medio-lateral, anterio-posterior and vertical axes. Some obtained data are novel or rarely associated together and enable a better understanding of the rower movement.     

尼科拉耶娃竞走技术诊断及分析

以国际田联规定的竞走定义为依据,采用现场技术动作录像及技术动作高速摄影的方法,对俄罗斯的尼科拉耶娃在1995年世界杯竞走赛的比赛技术进行诊断。技术诊断结果如下:(1)在10km赛程中能够保持稳定的步长,且步长与步频合理;(2)单步技术中腾空时间处于不可见腾空时限,且躯干角合理,身体重心上下起伏较小;(3)单步技术中前脚着地时脚掌与地面的仰角合理,支撑腿至垂直部位的膝角正确。     

A biomechanical comparison of the topspin and backspin forehand approach shots in tennis

Three-dimensional (3-D) high-speed cinematographic techniques were used to record topspin and backspin forehand approach shots hit down-the-line by high-performance players. The direct linear transformation (DLT) technique was used in the 3-D space reconstruction from 2-D images recorded via laterally placed phase-locked cameras operating at 200 Hz. A Mann-Whitney U-test was calculated for the different aspects of the topspin and backspin shots to test for significance (P less than 0.05). A significant difference was recorded between topspin and backspin shots in the angle of the racket at the completion of the backswing. The racket was taken 0.48 rad past a line drawn perpendicular to the back fence for topspin trials, but only rotated 0.86 rad from a line parallel to the net in the backspin shot. Maximum racket velocities occurred prior to impact and were significantly higher in topspin (26.5 m s-1) compared to backspin (16.6 m s-1) trials. This resulted in the topspin trials recording a significantly higher ball velocity compared to backspin trials (27.6 m s-1 vs 21.7 m s-1). Pre-impact racket trajectories revealed that in topspin shots the racket moved on an upward path of 0.48 rad while in backspin shots it moved down at an angle of 0.34 rad. In the topspin trials impact occurred significantly further forward of the front foot than in backspin shots (0.26 m vs 0.05 m) while the angle of the racket was the same for both strokes (0.14 rad behind a line parallel to the net). The mean angle of the racket-face at impact was inclined backwards by 0.11 rad for backspin strokes and rotated forward by 0.13 rad for topspin strokes. Angles of incidence and reflection of the impact between the ball and the court showed that backspin trials had larger angles of incidence and reflection than topspin strokes.