The biomechanics of the triple jump: A review

Abstract

The purpose of this paper is to review the published opinions of coaches and the findings of scientists concerning the techniques used in the triple jump, and to identify promising avenues for future research on the subject. A model is developed to identify those factors that have a causal role in determining the official distance of a triple jump. This model is then used as a basis for the subsequent review. The review itself considers each of the biomechanical factors identified in the model, some additional factors reported in the literature, and selected characteristics of triple jumping techniques. It is concluded that research on triple jump techniques has been sparse and has had little impact on practice. Identification of the individual attributes that determine the optimum ratio of the phase distances for a given athlete, the loads to which the supporting legs are subjected and the control of balance during a triple jump are seen as challenging and potentially useful topics of future research.     

极点对青少年竞走技术的影响

通过极点对青少年竞走技术影响的调查分析，对竞走比赛中是否存在极点、极点反应对竞走技术有何影响等进行研究，为教练员、运动员在训练和比赛时提供参考。     

竞走运动的足底压力及身体姿态特征分析

竞走作为一项流行运动与人类其他行走方式有着根本的区别。本研究的目的是描述竞走过程中的动力学和运动学指标与正常走各指标的差异,探讨受限于竞走规则的动作是否会造成对竞走运动员的潜在伤害。研究选取14名优秀竞走运动员作为测试对象,使用Rs-SCaB测力板和3台SONY摄像机采集竞走和正常走的动力学和运动学指标,采用配对T检验的统计学方法来比较两种行走方式的指标差异。在竞走中,足跟外侧（H1）和足跟内侧（Hm）压力峰值、地面反作用力第一、第二压力峰值和谷值大小、压力中心曲线在前后方向和左右方向的位移等指标都显著大于正常走。支撑腿着地时伸直的膝关节引起了足跟外侧（H1）和足跟内侧（Hm）压强峰值的增大;竞走中较大的水平速度、较大的水平冲力和较快的踝关节背伸速度分别造成了地面反作用力第一、第二峰值和谷值的增大;更多的大脚趾肌肉用力和较大的髋关节内收动作造成了竞走时足底压力中心曲线在前后方向和内外方向的位移增大。竞走时较大的足跟部位压力峰值和较大的踝关节外翻角度以及大脚趾肌群的过度利用可能是由竞走规则导致的潜在伤病因素。     

Kinematic characteristics of elite men's and women's 20 km race walking and their variation during the race

The aim of this study was to analyse the important kinematic variables in elite men's and women's 20 km race walking. Thirty men and 30 women were analysed from video data recorded during the World Race Walking Cup. Video data were also recorded at four points during the European Cup Race Walking and 12 men and 12 women analysed from these data. Two camcorders operating at 50 Hz recorded at each race for 3D analysis. The two main performance determinants of speed were step length and cadence. Men were faster than women because of their greater step lengths but there was no difference in cadence. A reduction in step length was the initial cause of slowing down with later decreases in speed caused by reductions in cadence. Shorter contact times were important in optimising both step length and cadence, and faster athletes tended to have longer flight times than slower athletes. It was less clear which other kinematic variables were critical for successful walking, particularly with regard to joint angles. Different associations were found for some key variables in men and women, suggesting that their techniques may differ due to differences in height and mass.     

The influence of hip mobility and quadriceps fatigue on sagittal spinal posture and muscle activation in rugby scrum performance

Rugby Union scrumming puts the spine under a high degree of loading. The aim of the current study was to determine how sagittal hip range of motion and quadriceps fatigue influence force output, spinal posture, and activation of the trunk and quadriceps muscles in rugby scrumming. Measures of sagittal hip flexion/extension range of motion were collected from 16 male varsity and club first XV level participants. Sagittal spine motion (electromagnetic motion capture), trunk and quadriceps activation (electromyography), and applied horizontal compressive force (force plate) were measured during individual machine scrumming. Participants performed a 5-trial scrum block involving 5?s of contact with 1–2?min recovery between each trial. They then performed a fatiguing protocol (wall sit to failure) and immediately returned to the scrum machine to perform another five trials. Though there was no significant influence of fatigue on the horizontal compressive force applied during contact (P?=?.83), there was a 52% increase in cervical flexion (P?P?P?相似文献   

The biomechanics of soccer: A review

Abstract

The purpose of this investigation was to determine whether combining two mental preparation strategies would be more effective in enhancing performances than a single strategy. Subjects (n = 40) practiced on a basketball free throw task (20 shots) using one of the following mental preparation strategies: (a) imagery, (b) relaxation, (c) relaxation plus imagery, (d) placebo control. To simulate game conditions, subjects were allowed only 10 s in which to use their mental preparation strategy. After the practice session, subjects shot 20 test free throws using their designated technique. Results indicated a significant main effect with the imagery group performing significantly better than the placebo control group although there were no specific differences between the three experimental groups. The results are discussed in terms of potential variables mediating the effectiveness of imagery in enhancing sport performance, and future directions for research are offered.     

Effect of movement speed on trunk and hip exercise performance

Abstract

The influence of speed on trunk exercise technique is poorly understood. The aim of this study was to analyse the effect of movement speed on the kinematics and kinetics of curl-up, sit-up and leg raising/lowering exercises. Seventeen healthy, recreationally trained individuals (13 females and 4 males) volunteered to participate in this study. Four different exercise cadences were analysed: 1 repetition/4 s, 1 repetition/2 s, 1 repetition/1.5 s and 1 repetition/1 s. The exercises were executed on a force plate and recorded by three cameras to conduct a 3D photogrammetric analysis. The cephalo-caudal displacement of the centre of pressure and range of motion (ROM) of six joints describing the trunk and hip movements were measured. As sit-up and curl-up speed increased, hip and knee ROM increased. Dorsal-lumbar and upper trunk ROM increased with speed in the curl-up. Faster cadence in the sit-up exercise had minimal effect on trunk ROM: only the upper trunk ROM decreased significantly. In the leg raising/lowering exercise there was a decrease in the pelvic tilt and hip ROM, and increased knee flexion ROM. During higher speed exercises, participants modified their technique to maintain the cadence. Thus, professionals would do well to monitor and control participants' technique during high-speed exercises to maintain performance specificity. Results also suggest division of speed into two cadence categories, to be used as a reference for prescribing exercise speed based on preferred outcome goals.     

The biomechanics of javelin throwing: a review

In this paper, the scientific literature and that on the sports sciences relevant to javelin throwing is critically reviewed. This is particularly timely because of the change in the specification of the javelin for the men's event, which was introduced by the IAAF in 1986. A full discussion of the aerodynamics of the javelin is presented with due consideration of the change in pitching moment characteristics that the rules change had brought about. The uses and limitations of current computer programs for simulating javelin flight, in order to estimate optimal release parameters, are profiled. Consideration is also given to the effects of wind velocity, air density, javelin weight and the flutter and spin of the javelin on its flight. The review further considers the optimization of release parameters, drawing upon computer simulations and field-based data. The effects of release speed, release height, release angle, release angle of attack and release pitch rate are assessed. The javelin throwing technique is discussed in relation to cinematographically derived data, including an evaluation of experimental procedures. The importance to successful performance of the grip, the run-up and transition phases, the cross over and delivery strides are each reviewed. Finally, some prognoses as to the direction of future research into this complex throwing skill are offered.     

核心力量在竞走训练中的作用探析

通过文献资料法、专家访谈法,总结归纳核心力量训练的理论基础,阐述其在竞走训练中的重要作用,同时提出竞走运动员核心力量训练的原则,旨在为当前从事竞走训练方面的学者和专家提供参考。     

第27届奥运会女子20公里竞走王丽萍、刘宏宇关键技术解析

国际田联的“竞走定义”规范了竞走比赛的技术动作标准。如果运动员违反“竞走定义”受到3名不同裁判员的严重警告，将被取消比赛资格，因此“竞走定义”成为竞走的关键技术。在第27届奥运会上王丽萍荣获女子20公里竞走项目金牌，但仍受到2名裁判员的严重警告。世界杯赛和世界锦标赛的双赛冠军刘洪宇，在第27届奥运会女子20公里比赛中于16公里处，因受到3名不同裁判员的严重警告，被取消比赛资格，失去争夺金牌的机会。因此，对王丽萍、刘宏宇竞走关键技术的解析是必要的，对符合“竞走定义”的技术给予巩固，对违反“竞走定义”的技术给予改进。     

北京奥运会女子20 km竞走中外优秀运动员比赛特征对比分析

对北京奥运会女子20 km竞走比赛中外优秀运动员犯规特征和速度特征进行对比分析研究,结果表明:我国运动员腾空性质犯规仍是技术犯规的主要问题,技术发挥不稳定;比赛最高速度与最低速度变化较大,体力分配不均;比赛后半程体能下降过快.     

我国竞走项目青少年阶段训练安排的现状分析

对我国竞走项目青少年阶段训练安排现状进行研究后认为:竞走项目青少年阶段训练安排存在训练理念落后、内容单调、早期专项化、过量训练以及训练模式成人化等问题。建议:通过教练员能力培养、改变青少年教练员考核标准、改良三级训练体制、针对青少年阶段生理与心理特征设计有的放矢的训练计划等策略来提高青少年竞走运动员训练目标的长远性与训练过程的系统性,避免教练员因急功近利而导致的青少年训练早期专项化与过量训练现象。     

Effect of attending to a ball during a side-cut maneuver on lower extremity biomechanics in male and female athletes

Many sports associated with anterior cruciate ligament (ACL) injury require athletes attend to a ball during participation. We investigated effects of attending to a ball on lower extremity mechanics during a side-cut maneuver and if these effects are consistent for males and females. Sagittal and frontal plane hip and knee kinematics and joint moments were measured during side-cut maneuvers in 19 male and 19 female National Collegiate Athletic Association division III basketball players. Participants also experienced two side-cut conditions that required attention to a ball. Our results did not indicate that the effect of attention varies with gender. However, during side-cut conditions while attending to a ball, internal knee adductor moment was 20% greater (p = 0.03) and peak knee flexion angle was 4° larger (p < 0.01). Females demonstrated 5° less hip flexion (p = 0.046), 12° less knee flexion (p < 0.01), and 4° more knee abduction (p = 0.026) at initial contact during all side-cut conditions than males. Attention to a ball may affect lower extremity mechanics relevant to ACL injury. The validity of laboratory studies of lower extremity mechanics for sports that include attention to a ball may be increased if participants are required to attend to a ball during the task.     

Reliability of lower limb biomechanics in two sport-specific sidestep cutting tasks

The purpose of this study was to assess the within- and between-session reliability of lower limb biomechanics in two sport-specific sidestep cutting tasks performed by elite female handball and football (soccer) athletes. Moreover, we aimed at determining the minimum number of trials necessary to obtain a reliable measure. Nineteen elite female handball and 22 elite female football (soccer) athletes (M ± SD: 22 ± 4 yrs old, 168 ± 5 cm, 66 ± 8 kg) were tested. The reliability was quantified by intra-class correlations (ICCs), typical error and Spearman’s rank correlation. Only minor improvements in ICC values were seen when increasing the number of trials from 3 to 5. Based on trials 1–3, all variables showed good to excellent within-session reliability (M ICC: 0.91, 95% CI: 0.89–0.93), fair to good between-session reliability (M ICC: 0.73, 95% CI: 0.70–0.76), moderately positive between-session rank correlation coefficients (M: 0.72, 95% CI: 0.69–0.76). A few frontal plane biomechanical variables displayed lower between-session reliability in the football task compared with the handball task. The moderately positive between-session ranking and practically small typical error implies that the measurements could reliably reproduce the ranking of individuals in multiple-session studies. Adequate reliability could be attained from 3 trials, with only minor improvements when adding more trials.     

The biomechanics of twisting somersaults Part III: Aerial twist

A simulation model and a rigid body model are used to evaluate aerial twisting techniques. It is found that when somersault is not present, a number of cycles of segment counter‐rotation are required to produce one twist. When somersault is present, twist may be introduced by producing tilt using asymmetrical movements of the arms, chest or hips about the sagittal plane. The same asymmetrical movements may be used to remove tilt, although the effectiveness of these techniques is dependent upon body configuration and the direction of somersault.     

The child and exercise: an overview

In this paper the complex topic of 'the child and exercise' is approached from a multidisciplinary angle. Research concerned with effects of exercise on growth and development is reviewed. In spite of traditional beliefs, there is not enough evidence to support the view that regular and intense physical training promotes an increase in body size, nor is there any physiological evidence that severe training has any harmful effect on the body. Exercise capacity and aerobic power increase gradually throughout childhood. Investigations have shown that children aged 10 years or younger do not react with an increased VO2 max as one would expect from endurance activities. The trainability of endurance seems to depend on the biological maturity level of growing children. After puberty the effects of endurance training are similar to those reported for adults. Just how much physical activity is necessary or optimal during the growing years is not known because individual variation is great. Even fewer results are available on the trainability of anaerobic capacity. The trainability of other factors such as strength, speed, flexibility and coordination is amply discussed. Finally some thoughts are given to young female athletes, both early and late maturers, with respect to their sport performance and expectancies.     

The biomechanics of twisting somersaults Part II: Contact twist

A simulation model and a rigid body model are used to investigate twisting initiated during the take‐off or contact phase. It is shown that it is possible to produce a full twist solely by building up angular momentum in the arms during the contact phase. This method is only half as effective as building up momentum in the whole body during contact. The introduction of twist into a somersault changes the somersault rate by less than 1%. By timing arm adduction appropriately, it is possible to take advantage of nutation and boost the initial value of the tilt angle and so obtain a greater twist rate. Twist may be stopped by the action of piking, since the motion changes from the twisting mode to the wobbling mode of rigid body motion. Transition to and from these two modes can be used to increase or decrease the tilt angle and twist rate.     

The penalty throw in water polo: A cinematographic analysis

Three‐dimensional (3‐D) high‐speed cinematography was used to record the penalty throw in water polo by six elite male (M) and six elite female (F) players. The direct linear transformation technique (DLT) was used in the 3‐D space reconstruction from 2‐D images recorded via laterally placed phase‐locked cameras operating at 200 Hz. Five of the twelve subjects lifted the ball from underneath at the start of the throw whilst the remaining subjects opted for a rotation lift. As the ball was brought behind the head the females used very little hip and shoulder rotation compared to the male players so that four of the six female subjects were square on to the target at the rear point. At the completion of the backswing the wrist was flexed to a similar angle (M‐162°; F‐158°); the elbow angle showed significantly greater flexion for females (85°) than males (107°).

During the forward swing, from rear point to release, the wrist joint of the female players flexed from a rear point angle of 158° to 148° at release. The wrist movement for male subjects was different from the females in that it flexed from 162° to 147°, 0.10 s prior to release and then extended to 159° at palmar release before again flexing to 156° at release. The amount of elbow extension during the forward swing was 48° for both groups; however, the females actually released the ball with the forearm vertical (89°) compared to the male forearm angle of 78°. Maximum angular velocity of the wrist and elbow occurred at release for 9 of the 12 subjects. Both the wrist and elbow joints (F‐148°; M‐156° at wrist and F‐126°; M‐148° at elbow) demonstrated greater flexion at release in female subjects, compared with males. Maximum linear endpoint velocities for the forearm and hand segments occurred at ball release resulting in mean ball velocities of 19.1 m s ^‐1 and 14.7 m s^{‐ 1} for male and female subjects respectively.     

Bend sprinting performance: new insights into the effect of running lane

Athletes in inner lanes may be disadvantaged during athletic sprint races containing a bend portion because of the tightness of the bend. We empirically investigated the veracity of modelled estimates of this disadvantage and the effect of running lane on selected kinematic variables. Three-dimensional video analysis was conducted on nine male athletes in lanes 8, 5 and 2 of the bend of an outdoor track (radii: 45.10, 41.41 and 37.72 m, respectively). There was over 2% (p < 0.05) reduction in mean race velocity from lane 8 (left step 9.56 ± 0.43 m/s, right step: 9.49 ± 0.41 m/s) to lane 5 (left step: 9.36 ± 0.51 m/s, right step: 9.30 ± 0.51 m/s), with only slight further reductions from lane 5 to lane 2 (left step: 9.34 ± 0.61 m/s, right step: 9.30 ± 0.63 m/s). Race velocity decreased mainly because of reductions in step frequency as radius decreased. These unique data demonstrate the extent of the disadvantage of inner lane allocation during competition may be greater than previously suspected. Variations in race velocity changes might indicate some athletes are better able to accommodate running at tighter radii than others, which should have implications for athletes’ training.     

十运会与雅典奥运会女子20 km竞走犯规分析

通过对十运会与雅典奥运会女子20km竞走比赛裁判判罚情况的对比,对我国竞走运动员犯规的性质、时间、频数等进行分析。结果表明:腾空性质犯规仍是技术犯规的主要问题,但屈膝性质犯规所占比例明显增多,犯规高峰期出现早,技术不稳定。