THE USE OF MOTION ANALYSIS AS A COACHING AID TO IMPROVE THE INDIVIDUAL TECHNIQUE IN SPRINT HURDLES

Biomechanical data are oflen presented as a group average, which may not always help individual athletes to improve their own performance. The purpose of this study was to analyse techniques in sprint hurdles within the athlete and find critical individual aspects, which influence performance. The hurdle clearance of three athletes (eight trials each) were videotaped with four video camera recorders and analysed three-dimensionally. There were several statistically significant correlations between the critical overall horizontal velocity and other variables, especially for one athlete. Such trends in individual performance presented ideas to coaches, athletes and also to researchers, regarding what happened in less successful runs and which technical points were worth individual attention in training

VARIATION IN MOTION ANALYSIS OF SPRINT HURDLES: PART 1CO-ORDINATE DEVIATION IN 3-DIMENSIONAL RECONSTRUCTION

INTRODUCTION. An understanding of the different variation sources in experimental sport research is fundamental to technical analysis (Yeadon, 1994). Individual variable level variation in the event of sprint hurdles was presented by Salo el al. (1995). The aim of this study was to investigate the variation al the digitised co-ordinate level. METHODS Hurdle c1earances were videotaped with two genlocked cameras (50 Hz, at a 90 degree angle from the hurdle symmetrically on both sides of the lane). Two randomly selected trials (female and male) were digitised eight times by the same operator using APAS. The separate raw co-ordinates (u, v) of both camera views and the raw 30 co-ordinates (after OLT) 01 all digitised trials were transformed to Excel software. Standard deviation (SO) for the all 18 body landmarks were calculated separately for every single analysed field. The lowest SO of each condition and each co-ordinate direction (including diagonal combination) was selected as a base unit. All other SOs were standardised to these base units. RESULTS The mean SO of each landmark over all digitised fjelds in u-and v-directions ranged fram 2.3 to 8.7 (female) and from 2.6 to 7.1 (male) relative SO units. This variation resulted in SO of 0.017, 0.009, 0.016 and 0.025 m in X-, y-, z-and diagonal directions, respectively, for the female athlete as a maxirna mean of an individual landmark in the 30 re-construction. The respective SO values for the male trial were 0.017, 0.012, 0.018 and 0.027m. The maximum variation of an individual landmark in a single field of one view was 22.5 SO-units (female) and 30.0 SO-units (male). However, most of the landmarks had less than 4 SO-units variation in most of the analysed fields. DISCUSSION The lowest SO was selected for the base unit, as this presented the most accurate situation which an operator was able to reach in repeated digitising. Generally at an average level, the variation of raw 3D coordinates can be considered acceptable. However, there were c1early problematic situations, when landmarks gained up to 30 times more variation in a single field than the best situation. The influence of this huge variation on variables depends upon whether it appears at a critical moment. In this study, the largest variation occurred in an air phase around the highest point of the flight path. For the male athlete, the trailleg and the ipsilateral arm were obstructed by the trunk for the other camera view. This had only a slight eHect on the maximum height of the centre of mass (GM) (SO= 0.01 m). However, the distance of the GM peak to the hurdle varied significantly (SO= 0.11 m). Oue to lower trail leg path Ihe same problem did not occur for the female athlete (SO= 0.00 and 0.01 m, respectively). Based on this study, it is elear that large variation occurs in manual digitising at the co-ordinate level and this variation can have critica! and important effects for variable values. REFERENCES Salo, A., Grimshaw, P.N. & Viitasalo, J.T. (1995). The repeatabIlity of motion analysis and the reproducibility of athletes in sprint hurdles. In: XlIIISBS Symposium. Abstracts. Thunder Bay, Ontario, Canada. Yeadon, M.A., & Ghallis, J.H. (1994). The future of pertormance-related sports biomechanics research. Journal 01 Sports Sciences, 12, 3-32

AN EXPERT SYSTEM FOR TALENT SEARCHING IN LONG DISTANCE RUNNING

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Balancing profitability of energy production, societal impacts and biodiversity in offshore wind farm design

The global demand for renewable energy is on the rise. Expansion of onshore wind energy is in many parts of the world limited by societal acceptance, and also ecological impacts are a concern. Here, pragmatic methods are developed for the integration of high-dimensional spatial data in offshore wind energy planning. Over 150 spatial data layers are created, which either oppose or support offshore wind energy development, and represent ecological, societal, and economic factors. The method is tested in Finland, where interest in developing offshore wind energy is growing. Analyses were done using a spatial prioritization approach, originally developed for the prioritization of high dimensional ecological data, and rarely used in planning offshore wind energy. When all criteria are integrated, it is possible to find a balanced solution where offshore wind farms cause little disturbance to biodiversity and society, while at the same time yielding high profitability for wind energy production. Earlier proposed areas for offshore wind farms were also evaluated. They were generally well suited for wind power, with the exception of a couple of areas with comparatively high environmental impacts. As an outcome, new areas well suited for large scale wind power deployment were recognized, where construction costs would be moderate and disturbance to biodiversity, marine industries and people limited. A novel tradeoff visualization method was also developed for the conflicts and synergies of offshore energy deployment, which could ease the dialogue between different stakeholders in a spatial planning context. Overall, this study provides a generic and transparent approach for well-informed analysis of offshore wind energy development potential when conflict resolution between biodiversity, societal factors and economic profits is needed. The proposed approach is replicable elsewhere in the world. It is also structurally suitable for the planning of impact avoidance and conflict resolution in the context of other forms of construction or resource extraction.Peer reviewe

Changes in BMI and physical activity from youth to adulthood distinguish normal-weight, metabolically obese adults from those who remain healthy

HighlightsAdults with MONW have a lower BMI during youth until young adulthood, but higher BMI after this than adults with metabolically healthy normal weight. Adults with MONW have a greater decrease in physical activity from youth to adulthood than other adults. Healthy lifestyle is important in the prevention of metabolic disorders, particularly in individuals who are slim in childhood.BackroundIndividuals with metabolically obese normal-weight (MONW) have higher risk of cardiovascular events than those with obesity but a metabolically healthy status. Etiological factors leading to MONW are not well known. We hypothesized distinct trajectories of changes in BMI and physical activity may modify metabolic risk and distinguish individuals with MONW from those who remain healthy.MethodsWe compared the mean levels of BMI and physical activity at eight time points (1980, 1983, 1986, 1989, 1992, 2001, 2007, 2011) between MONW and healthy normal-weight adults using linear mixed-model analysis. The analyses included 1180 participants of the Cardiovascular Risk in Young Finns study, a population-based study that represents six different age cohorts 3, 6, 9, 12, 15 and 18 years of age at baseline.ResultsIndividuals with adult MONW had significantly lower BMI in childhood and young adulthood, but their BMI increased more than in other adults after this age (pConclusionsRelative leanness in youth and subsequent weight gain in young adulthood, and a gradual decrease in physical activity levels from youth to adulthood, predispose normal-weight individuals to metabolic impairments. The results highlight the importance of a healthy lifestyle in the prevention of metabolic disorders, particularly in individuals who are slim in childhood.</p

Changes in BMI and physical activity from youth to adulthood distinguish normal-weight, metabolically obese adults from those who remain healthy

Highlights: Adults with MONW have a lower BMI during youth until young adulthood, but higher BMI after this than adults with metabolically healthy normal weight. Adults with MONW have a greater decrease in physical activity from youth to adulthood than other adults. Healthy lifestyle is important in the prevention of metabolic disorders, particularly in individuals who are slim in childhood. Background: Individuals with metabolically obese normal-weight (MONW) have higher risk of cardiovascular events than those with obesity but a metabolically healthy status. Etiological factors leading to MONW are not well known. We hypothesized distinct trajectories of changes in BMI and physical activity may modify metabolic risk and distinguish individuals with MONW from those who remain healthy. Methods: We compared the mean levels of BMI and physical activity at eight time points (1980, 1983, 1986, 1989, 1992, 2001, 2007, 2011) between MONW and healthy normal-weight adults using linear mixed-model analysis. The analyses included 1180 participants of the Cardiovascular Risk in Young Finns study, a population-based study that represents six different age cohorts 3, 6, 9, 12, 15 and 18 years of age at baseline. Results: Individuals with adult MONW had significantly lower BMI in childhood and young adulthood, but their BMI increased more than in other adults after this age (p<0.001for interaction between time and MONW status). Physical activity decreased relatively more since youth in individuals with adult MONW (p<0.001). Conclusions: Relative leanness in youth and subsequent weight gain in young adulthood, and a gradual decrease in physical activity levels from youth to adulthood, predispose normal-weight individuals to metabolic impairments. The results highlight the importance of a healthy lifestyle in the prevention of metabolic disorders, particularly in individuals who are slim in childhood.publishedVersionPeer reviewe