Accuracy between optical and inertial motion capture systems for assessing trunk speed during preferred gait and transition periods     

Martin Kokholm Fleron  Niels Christian Hauerbach Ubbesen  Francesco Battistella  David Leandro Dejtiar 《Sports biomechanics / International Society of Biomechanics in Sports》2019,18(4):366-377

Motion capture through inertial sensors is becoming popular, but its accuracy to describe kinematics during changes in walking speed is unknown. The aim of this study was to determine the accuracy of trunk speed extracted using an inertial motion system compared to a gold standard optical motion system, during steady walking and stationary periods. Eleven participants walked on pre-established paths marked on the floor. Between each lap, a 1-second stationary transition period at the initial position was included prior to the next lap. Resultant trunk speed during the walking and transition periods were extracted from an inertial (240 Hz sampling rate) and an optical system (120 Hz sampling rate) to calculate the agreement (Pearson’s correlation coefficient) and relative root mean square errors between both systems. The agreement for the resultant trunk speed between the inertial system and the optical system was strong (0.67 < r ≤ 0.9) for both walking and transition periods. Moreover, relative root mean square error during the transition periods was greater in comparison to the walking periods (>40% across all paths). It was concluded that trunk speed extracted from inertial systems have fair accuracy during walking, but the accuracy was reduced in the transition periods.  相似文献   

Conditioning exercises in ski jumping: biomechanical relationship of squat jumps,imitation jumps,and hill jumps     

Silvio Lorenzetti  Fabian Ammann  Sabrina Windmüller  Ramona Häberle  Sören Müller  Micah Gross 《Sports biomechanics / International Society of Biomechanics in Sports》2019,18(1):63-74

As hill jumps are very time-consuming, ski jumping athletes often perform various imitation jumps during training. The performed jumps should be similar to hill jumps, but a direct comparison of the kinetic and kinematic parameters has not been performed yet. Therefore, this study aimed to correlate 11 common parameters during hill jumps (Oberstdorf Germany), squat jumps (wearing indoor shoes), and various imitation jumps (rolling 4°, rolling flat, static; jumping equipment or indoor shoes) on a custom-built instrumented vehicle with a catch by the coach. During the performed jumps, force and video data of the take-off of 10 athletes were measured. The imitation and squat jumps were then ranked. The main difference between the hill jumps and the imitation and squat jumps is the higher maximal force loading rate during the hill jumps. Imitation jumps performed on a rolling platform, on flat ground were the most similar to hill jumps in terms of the force–time, and leg joint kinematic properties. Thus, non-hill jumps with a technical focus should be performed from a rolling platform with a flat inrun with normal indoor shoes or jumping equipment, and high normal force loading rates should be the main focus of imitation training.  相似文献   

Ankle taping can reduce external ankle joint moments during drop landings on a tilted surface     

Nahoko Sato  Hiroyuki Nunome  Luke S. Hopper  Yasuo Ikegami 《Sports biomechanics / International Society of Biomechanics in Sports》2019,18(1):28-38

Ankle taping is commonly used to prevent ankle sprains. However, kinematic assessments investigating the biomechanical effects of ankle taping have provided inconclusive results. This study aimed to determine the effect of ankle taping on the external ankle joint moments during a drop landing on a tilted surface at 25°. Twenty-five participants performed landings on a tilted force platform that caused ankle inversion with and without ankle taping. Landing kinematics were captured using a motion capture system. External ankle inversion moment, the angular impulse due to the medio-lateral and vertical components of ground reaction force (GRF) and their moment arm lengths about the ankle joint were analysed. The foot plantar inclination relative to the ground was assessed. In the taping condition, the foot plantar inclination and ankle inversion angular impulse were reduced significantly compared to that of the control. The only component of the external inversion moment to change significantly in the taped condition was a shortened medio-lateral GRF moment arm length. It can be assumed that the ankle taping altered the foot plantar inclination relative to the ground, thereby shortening the moment arm of medio-lateral GRF that resulted in the reduced ankle inversion angular impulse.  相似文献   

热习服对瑜伽初习者特定动作中气体代谢指标变化的影响     

蒋街良  陈赛红 《广州体育学院学报》2019,(4):102-105

采用Qualisys（Oqus700+）三维运动捕捉系统对4名广东省优秀短距离自由泳运动员出发技术测试,并用Visual 3D三维运动软件对准备姿势阶段、离台阶段、入水阶段、水下阶段和出水阶段的技术指标进行分析,阐述这四名运动员出发技术的运动学特征,试图为进一步提高其技术水平、稳步提高他们的比赛成绩提供参考。  相似文献   

对竞技健美操C组跳与跃类0.9分值难度动作的运动学分析   总被引：2，自引：1，他引：2  

杨锋 《山东体育学院学报》2006,22(3):85-89

用高速摄像解析方法,对竞技健美操C组中的有代表意义的跳与跃类0.9分值难度动作进行运动学分析,深入探究其动作技术原理,找出该动作的正确技术要领和关键技术,提供有关运动学参数,旨在为健美操的动作技术发展提供依据.  相似文献   

棒球投手肩关节旋转运动特征研究   总被引：4，自引：0，他引：4  

何勇 《山东体育学院学报》2006,22(3):107-109

棒球比赛中,投手是一支球队的灵魂,在很大程度上决定全局的比赛。肩部力量素质和活动范围是投手有效投球的基础,在很大程度上决定投球技术、机能的发挥。肩关节既是躯干和上肢的连结点,又是上肢运动的支点,是保证上肢完成三维活动的重要结构[1]。因此,肩关节在棒球运动中发挥着  相似文献   

A biomechanical comparison of successful and unsuccessful power clean attempts     

Kristof Kipp  Carolyn Meinerz 《Sports biomechanics / International Society of Biomechanics in Sports》2017,16(2):272-282

Although the power clean is an almost ubiquitous exercise in the strength and conditioning setting, relatively little is known about the biomechanics of successful and unsuccessful power clean lift attempts. The purpose of this study was to determine biomechanical differences between successful and unsuccessful power clean lift attempts in male collegiate athletes. Fifteen male lacrosse players (Age: 20.1 ± 1.2; Height: 1.78 ± 0.07 m; Body mass: 80.4 ± 8.1 kg; Relative one-repetition maximum power clean: 1.25 ± 0.13 kg/kg) were videotaped during a lifting session that required the completion of maximal effort power cleans to establish a one-repetition maximum. The position of the barbell was digitised and used to calculate the displacement, velocity, acceleration, and acceleration vector of the barbell. The results revealed that unsuccessful attempts were characterised by differences during the second pull phase. Unsuccessful lifts exhibited greater peak forward barbell displacement, lower backward barbell velocities, and lower resultant acceleration angles during the second pull. Strength and conditioning coaches should therefore emphasise limited forward motion of the barbell during the second pull and instruct athletes to generate a more backward-directed force during the second pull in order to lift greater loads during testing and subsequent lifting sessions.  相似文献   

Side-to-side differences in lower extremity biomechanics during multi-directional jump landing in volleyball athletes     

Komsak Sinsurin  Sarun Srisangboriboon  Roongtiwa Vachalathiti 《European Journal of Sport Science》2017,17(6):699-709

Side-to-side differences of lower extremities may influence the likelihood of injury. Moreover, adding the complexity of jump-landing direction would help to explain lower extremity control during sport activities. The aim was to determine the effects of limb dominance and jump-landing direction on lower extremity biomechanics. Nineteen female volleyball athletes participated. Both dominant limbs (DLs) and non-dominant limbs (NLs) were examined in single-leg jump-landing tests in four directions, including forward (0°), diagonal (30° and 60°), and lateral (90°) directions. Kinematic marker trajectories and ground reaction forces were collected using a 10 camera Vicon system and an AMTI force plate. Repeated measures ANOVA (2?×?4, limb?×?direction) was used to analyse. The finding showed that, at peak vertical GRF, a significant interaction of limb dominance and direction effects was found in the hip flexion angle and lower extremity joint kinetics (p?<?.05). NLs and DLs exhibited significantly different strategies while landing in various directions. Significantly higher increase of ankle dorsiflexion angle was observed in lateral direction compared to other directions for both DLs and NLs (p?<?.05). Increasingly using ankle dorsiflexion was observed from the forward to the lateral direction for both DLs and NLs. However, NLs and DLs preferentially used different strategies of joint moment organization to respond to similar VGRFs in various directions. The response pattern of DLs might not be effective and may expose DLs to a higher injury risk, especially with regard to landing with awkward posture compared with NLs.  相似文献   

Soreness-related changes in three-dimensional running biomechanics following eccentric knee extensor exercise     

Max R. Paquette  Shelby A. Peel  Brian K. Schilling  Dan A. Melcher  Richard J. Bloomer 《European Journal of Sport Science》2017,17(5):546-554

Runners often experience delayed onset muscle soreness (DOMS), especially of the knee extensors, following prolonged running. Sagittal knee joint biomechanics are altered in the presence of knee extensor DOMS but it is unclear how muscle soreness affects lower limb biomechanics in other planes of motion. The purpose of this study was to assess the effects of knee extensor DOMS on three-dimensional (3D) lower limb biomechanics during running. Thirty-three healthy men (25.8?±?6.8 years; 84.1?±?9.2?kg; 1.77?±?0.07?m) completed an isolated eccentric knee extensor damaging protocol to elicit DOMS. Biomechanics of over-ground running at a set speed of 3.35?m?s^?1±5% were measured before eccentric exercise (baseline) and, 24?h and 48?h following exercise in the presence of knee extensor DOMS. Knee flexion ROM was reduced at 48?h (P?=?0.01; d?=?0.26), and peak knee extensor moment was reduced at 24?h (P?=?0.001; d?=?0.49) and 48?h (P?<?0.001; d?=?0.68) compared to baseline. Frontal and transverse plane biomechanics were unaffected by the presence of DOMS (P?>?0.05). Peak positive ankle and knee joint powers and, peak negative knee joint power were all reduced from baseline to 24?h and 48?h (P?<?0.05). These findings suggest that knee extensor DOMS greatly influences sagittal knee joint angular kinetics and, reduces sagittal power production at the ankle joint. However, knee extensor DOMS does not affect frontal and transverse plane lower limb joint biomechanics during running.  相似文献   

The effects of barbell load on countermovement vertical jump power and net impulse     

Peter D. Mundy  Neal A. Smith  Mike A. Lauder  Jason P. Lake 《Journal of sports sciences》2017,35(18):1781-1787

The aim of this study was to examine the effects of barbell load on countermovement vertical jump (CMJ) power and net impulse within a theoretically valid framework, cognisant of the underpinning force, temporal, and spatial components. A total of 24 resistance-trained rugby union athletes (average ± SD: age: 23.1 ± 3.4 years; height: 1.83 ± 0.05 m; body mass (BM): 91.3 ± 10.5 kg) performed maximal CMJ under 5 experimental conditions in a randomised, counterbalanced order: unloaded, and with additional loads of 25%, 50%, 75%, and 100% of BM. Peak power and average power were maximised during the unloaded condition, both decreasing significantly (P < 0.05) as load increased. Net impulse was maximised with 75% of BM, which was significantly greater (P < 0.05) than the unloaded and 100% of BM conditions. Net mean force and mean velocity were maximised during the unloaded condition and decreased significantly (P < 0.05) as load increased, whereas phase duration increased significantly (P < 0.05) as load increased. As such, the interaction between barbell load and the underpinning force, time, and displacement components should be considered by strength and conditioning coaches when prescribing barbell loads.  相似文献