Optimisation of performance in running jumps

Running jumps such as the high jump and the long jump involve complex movements of the human body. The factors affecting performance include approach conditions, strength of the athlete and the muscle activation timings at each joint. In order to investigate the mechanics of jumping performances and the effect of these factors, an eight-segment, subject specific, torque-driven computer simulation model of running jumps was developed, evaluated and used to optimise performances of jumps for height and distance. Wobbling masses within the shank, thigh and trunk segments, and the ground-foot interface were modelled as non-linear spring-damper systems. The values for the stiffness and damping constants were determined through optimisation. The inertia data were obtained from anthropometric measurements on the subject using the inertia model of Yeadon (1990b). Joint torques predicted by the simulation model were expressed as a function of angular velocity and angle using data collected from an isovelocity dynamometer. The simulation model was evaluated by comparing the actual performances with simulations using kinematic and kinetic data collected. Movement of the wobbling masses was found to be in the region of 40 mm in the shank and thigh and 90 mm in the trunk. This movement resulted in a lower, more realistic initial peak in the ground reaction force. Co-contraction was found to occur at the joints during impact in order to increase the initial level of eccentric activation and also the rise time to maximum eccentric activation. Differences of 2% and 1% in the height and distance achieved were obtained between actual performances and simulations. An optimisation procedure was used to maximise the height reached and distance travelled by the mass centre, in simulations of jumps for height and distance respectively, by varying the torque generator activation time histories at each joint. An increase of 12% in the height reached by the mass centre in the jump for height and 14% in the distance reached by the mass centre in the jump for distance were achieved

Diane Wilson interview for a Wright State University History Course

On February 24, 2011 Cassie Higgins interview Diane Wilson, President of the American Tissue Association, for a class project dealing with oral histories and capturing the history of the Miami Valley. In the interview Diane talked about growing up in Everit[sic] Washington, moving to Dayton with her husband, and working at Community Tissue Services

KNEE JOINT KINEMATIC VARIABILITY OF THE TOUCHDOWN LEG DURING THE MAXIMAL VELOCITY PHASE OF SPRINT RUNNING

This study aimed to develop insight into knee joint kinematic variability of the touchdown leg during the maximal velocity phase of sprint running. Joint centre coordinate data were obtained for running trials performed by seven male athletes. Between and within athlete coefficient of variations were derived for step and sagittal plane knee joint angle variables. The minimum knee joint angle produced the largest between (13.3%) and within (8.4%) athlete variability and was related to velocity by an inverted U profile. The slowest and fastest athletes produced relatively higher step velocity variability than the intermediate athletes. The discrepancy in the within athlete step and knee joint kinematic variability of performers achieving similar gait-related objectives suggested a need to consider idiosyncratic kinematic patterns in developing sprint running performance

THE KINEMATIC SIMILARITY OF THE TRIPLE JUMP AND ASSOCIATED TRAINING DRILLS

The triple jump is a complex sporting movement consisting of three phases with the aim of maximising total jump distance. The ground contacts preceding the hop, step and jump phases largely determine the subsequent flight distances. The transition between the hop and step phases is said to be the most critical element in triple jumping performance (Jurgens, 1998) and the minimisation of horizontal momentum losses during ground contacts has been linked to successful performance (Hay, 1992). Triple jumpers employ a variety of drills to help facilitate the effective execution of the ground contacts between each of the phases. These drills attempt to expose the performer to the physical demands of the movement and to replicate the movement patterns that occur thereby serving the specificity training principle identified by Matveyev (1981). The first aim of this study was to quantify the losses in horizontal momentum during the hop-step transition and hence to assess the subsequent effect on performance. The second aim of the study was to identify which of the training drills used by triple jumpers most closely match the movement patterns utilised within a triple jump performance during this critical transition

INTRA-LIMB KINEMATIC STRATEGIES OF MAXIMUM VELOCITY PHASE SPRINT RUNNING PERFORMANCES

This study aimed to develop insight into the intra-limb kinematic strategies underpinning athlete- and step-based sprint running performances. Joint centre coordinate data were automatically tracked for maximum velocity phase sprint running trials of six well-trained athletes. The fastest athlete initiated the stance phase with a 16.0º and 3.4º more extended ankle and knee, and a corresponding 5.8º more flexed hip joint compared to the slowest athlete (

THE USE OF TRIPLE JUMP TRAINING DRILLS IN REPLICATING MOVEMENT COORDINATION PATTERNS

The purpose of this study was to investigate how effective triple jump training drills are at replicating the lower extremity coordination patterns utilised during the triple jump. Relative motion plots and a modified version of the vector coding technique were used to quantify the coordination patterns of the lower extremities in the triple jump and four related training drills. Differences were found to exist in the coordination patterns between the triple jump and static, but not dynamic, drills and these differences were mainly in the swing (free) leg. The results of this study suggest that if the primary purpose of the training drills is to replicate the movement patterns utilised in the triple jump then dynamic drills are more effective than static drills. In addition, coaches should focus on the use of the free leg during these training drill

AN IMAGE-BASED APPROACH TO OBTAINING ANTHROPOMETRIC MEASUREMENTS FOR ATHLETE-SPECIFIC INERTIA MODELLING

This study aimed to develop and evaluate an image-based method of obtaining anthropometric measurements for athlete-specific inertia modelling. Anthropometric measurements were obtained directly from five athletic performers and indirectly from digitization of whole-body still images. The direct and image-based measurements were used in Yeadon’s (1990) inertia model. The mean absolute accuracy in predicted whole-body mass achieved using the direct and image-based approach was 2.10% and 2.87%, respectively. The presented approach provided a successful alternative to direct measurement for obtaining anthropometric measurements for inertia modelling of athletic performers. The method offers a valuable solution for obtaining measurements from elite athletic performers for whom time-consuming data collections may be undesirabl

The Effect of Clinical Pilates on Functional Movement in Recreational Runners

AbstractBiomechanical imbalances and inefficient functional movements are considered contributing factors to running-related injuries. Clinical Pilates uses a series of exercises focused on retraining normal movement patterns. This study investigated whether a 6-week course of Clinical Pilates improves functional movement and thereby, potentially, reduces the risk of running-related injuries associated with movement dysfunction. A modified functional movement screen was used to analyze the functional movement ability of forty runners. Forty participants completed a 6-week course of Clinical Pilates delivered by a Clinical Pilates instructor. The movement screen was carried out 3 times for each runner: 6 weeks pre-intervention (baseline), within one week pre-intervention (pre) and within one week post-intervention (post). Repeated-measures analysis of variance and post-hoc tests found significant increases in scores between baseline and post (mean±SD; 13.4±2.4 vs. 17.0±1.7, p&lt;0.01) and pre and post (mean±SD; 13.5±2.5 vs. 17.0±1.7, p&lt;0.01), but no significant difference between baseline and pre (p=0.3). A 6-week course of Clinical Pilates significantly improves functional movement in recreational runners, and this may lead to a reduction in the risk of running-related injuries.</jats:p

THE EFFECT OF PACE ON STRIDE CHARACTERISTICS AND VARIABILITY IN SPRINT RUNNING

The purpose of this study was to investigate the influence of sprint running pace on stride characteristics and their associated variability. Stride characteristics were determined for four experienced male track athletes during sprint running trials at three specified paces. The influence of pace on the stride length and frequency were investigated along with the within subject coefficient of variation for the step frequency / length ratio and the stride velocity. Stride length and stride frequency were shown to influence velocity the greatest at the slowest and fastest paces respectively. Variability of the stride frequency / length ratio was shown to increase with pace whereas the variability of the stride velocity was shown to decrease with pace. Variability within the stride characteristics suggests athletes adopt a flexible control strategy which can adapt to potential perturbations

THE CONTROL OF ROTATION DURING RUGBY UNION GOAL KICKING

INTRODUCTION: While the basic kicking technique in ball sports is well understood, there has been limited research conducted on the biomechanics of rugby union goal kicking. Specifically, the movement characteristics which contribute to kicking accuracy have not been well defined. It is probable that the control of body rotation plays an important role in determining kicking accuracy. The quantity of rotation is characterised by the extent of angular momentum but surprisingly this quantity has seldom been used in analysis of kicking technique. This study aims to investigate how rugby players control rotation during execution of. the kicking action and to determine the relationship between segmental angular momentum contributions and kicking accuracy