THE INFLUENCE OF WEARING A LUMBAR SUPPORT BELT UPON JAVELIN THROWING PERFORMANCE

Six male javelin throwers (mean ±SD age 25 ± 4 years: height 1.82 ± 0.06 m; weight 891 ± 105 N) were filmed at 150 Hz throwing an 800g javelin from a polyflex athletic track with and without a lumbar support belt, to allow three- dimensional kinematic analysis. Two typical throws at similar run up velocities were analysed. Wearing the belt was associated with significantly greater peak velocity at the shoulder relative to the hip when the hyperextended torso flexed forwards to release the javelin (P=0.046). With the belt there was not a significant increase in the velocity of the arm segments or javelin release velocity, attitude angle, release height, though an insignificant increase of 1.45m in mean distance occurred (P>0.05) possibly due to javelin aerodynamic factors

GROUND REACTION FORCES OCCURING DURING THE DELIVERY STRIDE OF JAVELIN THROWING

Five male javelin throwers (mean ± SD: age 24 ± 3 years; height 1.83 ± 0.06 m; body weight 888 ± 117 N) performed outdoors. Two Kistler force platforms were mounted beneath an outdoor polyflex runway (0.017 m depth) with positioning adjustment for each subject's delivery stride length. For the back foot the mean (±SD) peak vertical ground reaction force was 2.31 ± 0.41 BW, and maximum total force was 2.36 ± 0.50 BW. For the front foot the mean peak vertical force was 5.63 ± 1.31 BW, the braking force was 4.50 ± 0.96 BW and maximum total force was 7.05 ± 1.57 BW. At the beginning of the delivery stride, when the back foot contacted the ground, the mean peak vertical loading rate was 115 ± 35 BW/s which was less than the front foot loading rate of 192 ± 64 BWs/s

RELATIONSHIP OF SHOE IMPACT, BRAKING AND PROPULSIVE FORCE

INTRODUCTION -Van Mechelen (1992) reported that runners having no preference for shoe brand sustained significantly fewer injuries This work aimed to investigate the influence of shoe type on ground reaction force during jogging. Ground reaction forces (vertical, anterior-posterior, mediolateral) were measured as the subjects right foot struck a 9581 Kistler force platform mounted in an outdoor profiex artificial track surface. Forces were sampled and stored using Orthodata Provec software running on a Viglen 386 computer system. Twelve sports students, six male (age 20.17 ±0.75 years; height 180 ±0,07m; weight 81.2 ± 7.0Kg (mean ±S.D)) and six female (age 19.7 ± 0.52 years; height 1.58 ± 0.15m; weight 61.0 ± 8.2Kg (mean ±S,D.)) were the subjects of the study. Following shoe habituation subjects jogged at preferred pace naturally in mild, dry conditions across the platform at least five consecutive times wearing each pair of shoes. Males wore 6 new pairs of shoes (Adidas Response Lite; Adidas Torsion Advance; Tech Performance; Puma Disc system TX4000; Puma Viento; Mizuno Mondo Elite) and females four pairs of shoes (Adidas Response Lite; Adidas Lady Tech Performance; Puma T-400; Puma liberte 11) in an individual random order. Jogging speeds were measured using infrared timing devices positioned 1m before and 1m after the force platform. Peak Forces were read subsequently from the computer screen using cursor measurement to locate peak forces. Following initial evaluation analysis was focused on the vertical and anterior-posterior torees. Mean peak vertical impact and maximal forces, mean peak braking and propulsive forces were expressed relative to each subject's body weight (BW), RESULTS -For the male subjects the mean peak vertical force range for alt shoes was 2.9 -3,OBW, impact force 2,5 -2.8BW, braking 0.62 -0.70BW, and propulsive OAO -OA4BW. For the females the mean peak range was vertical force 2.75 -2.78BW, impact force 2.1 -2.5BW, braking 0.57 -0.59BW, and propulsive 0.37 -0.41 BW. In both the male and female subjects a low mean peak braking force and low mean peak vertical impact force was associated with a high mean peak propulsive force (male: Adidas Tech Performance Braking 0.616BW, Impact 2.531 BW, Propulsive OA43BW; female: Adidas Response Lite Braking 0.572BW, Impact 2.072BW, Propulsive OA09BW). Similarly a high mean peak braking force and high mean peak impact force was associated with a low mean peak propulsive force (male: Puma Disc system TX4000 Braking 0.700BW, Impact 2.768BW, Propulsive OA02BW; female: Adidas Lady Tech Performance Braking 0.591 BW, Impact 2A82BW, Propulsive 0 379BW). Differences were significant (P < 005) CONCLUSION -For two shoe designs the existence of a lower vertical impact force and low braking force is associated with greater propulsive force

The effect of neoprene athletic supports on cricket bowling and javelin throwing

This study investigated the technique of the individual, using an integrated biomechanical approach, to assess injury potential and performance. The effects of five neoprene athletic supports were investigated for the cricket bowl and javelin throw. A significant improvement in distance thrown and an increase in linear speed of body segmental movements were found for a lumbar support belt during the javelin throw. A two-handed overhead throwing activity was designed to investigate the effect of this lumbar support belt during the hyperextension - flexion movement of the torso. Significant differences in the distances thrown and segmental timing during the belt condition were found for both novice and experienced athletes. An integrated approach (three-dimensional cinematography, ground reaction forces and electromyography) was then used to analyse the effect of this lumbar support belt during the delivery phase of both sporting activities. The rate at which the torso uncoiled, (the relative peak shoulder to peak hip speed) was found to be significantly different during the belt condition for both activities. The results of these experiments suggest that the lumbar support belt enabled a more efficient transfer of speed to the upper body. A significant improvement in distance thrown during the lumbar support belt condition was found for the javelin throw

Genetics and pathophysiology of mammalian sulfate biology

Nutrient sulfate is essential for numerous physiological functions in mammalian growth and development. Accordingly, disruptions to any of the molecular processes that maintain the required biological ratio of sulfonated and unconjugated substrates are likely to have detrimental consequences for mammalian physiology. Molecular processes of sulfate biology can be broadly grouped into four categories: firstly, intracellular sulfate levels are maintained by intermediary metabolism and sulfate transporters that mediate the transfer of sulfate across the plasma membrane; secondly, sulfate is converted to 3′-phosphoadenosine 5′-phosphosulfate (PAPS), which is the universal sulfonate donor for all sulfonation reactions; thirdly, sulfotransferases mediate the intracellular sulfonation of endogenous and exogenous substrates; fourthly, sulfate is removed from substrates via sulfatases. From the literature, we curated 91 human genes that encode all known sulfate transporters, enzymes in pathways of sulfate generation, PAPS synthetases and transporters, sulfotransferases and sulfatases, with a focus on genes that are linked to human and animal pathophysiology. The predominant clinical features linked to these genes include neurological dysfunction, skeletal dysplasias, reduced fecundity and reproduction, and cardiovascular pathologies. Collectively, this review provides reference information for genetic investigations of perturbed mammalian sulfate biology

Using a simulation model for knowledge elicitation and knowledge management

The work reported in this paper is part of a project simulating maintenance operations in an automotive engine production facility. The decisions made by the people in charge of these operations form a crucial element of this simulation. Eliciting this knowledge is problematic. One approach is to use the simulation model as part of the knowledge elicitation process. This paper reports on the experience so far with using a simulation model to support knowledge management in this way. Issues are discussed regarding the data available, the use of the model, and the elicitation process itself. © 2004 Elsevier B.V. All rights reserved

Ground reaction force, spinal kinematics and their relationship to lower back pain and injury in cricket fast bowling: A review

BACKGROUND: Fast bowlers display a high risk of lower back injury and pain. Studies report factors that may increase this risk, however exact mechanisms remain unclear. OBJECTIVE: To provide a contemporary analysis of literature, up to April 2016, regarding fast bowling, spinal kinematics, ground reaction force (GRF), lower back pain (LBP) and pathology. METHOD: Key terms including biomechanics, bowling, spine and injury were searched within MEDLINE, Google Scholar, SPORTDiscuss, Science Citation Index, OAIster, CINAHL, Academic Search Complete, Science Direct and Scopus. Following application of inclusion criteria, 56 studies (reduced from 140) were appraised for quality and pooled for further analysis. RESULTS: Twelve times greater risk of lumbar injury was reported in bowlers displaying excessive shoulder counter-rotation (SCR), however SCR is a surrogate measure which may not describe actual spinal movement. Little is known about LBP specifically. Weighted averages of 5.8 ± 1.3 times body weight (BW) vertically and 3.2 ± 1.1 BW horizontally were calculated for peak GRF during fast bowling. No quantitative synthesis of kinematic data was possible due to heterogeneity of reported results. CONCLUSIONS: Fast bowling is highly injurious especially with excessive SCR. Studies adopted similar methodologies, constrained to laboratory settings. Future studies should focus on methods to determine biomechanics during live play