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

Evaluation, Gap Analysis, and Potential Expansion of the Finnish Marine Protected Area Network

Peer reviewe

Identifying areas prone to coastal hypoxia - the role of topography

Hypoxia is an increasing problem in marine ecosystems around the world. While major advances have been made in our understanding of the drivers of hypoxia, challenges remain in describing oxygen dynamics in coastal regions. The complexity of many coastal areas and lack of detailed in situ data have hindered the development of models describing oxygen dynamics at a sufficient spatial resolution for efficient management actions to take place. It is well known that the enclosed nature of seafloors and reduced water mixing facilitates hypoxia formation, but the degree to which topography contributes to hypoxia formation and small-scale variability of coastal hypoxia has not been previously quantified. We developed simple proxies of seafloor heterogeneity and modeled oxygen deficiency in complex coastal areas in the northern Baltic Sea. According to our models, topographical parameters alone explained similar to 80 % of hypoxia occurrences. The models also revealed that less than 25 % of the studied seascapes were prone to hypoxia during late summer (August-September). However, large variation existed in the spatial and temporal patterns of hypoxia, as certain areas were prone to occasional severe hypoxia (O-2 <2 mg L-1), while others were more susceptible to recurrent moderate hypoxia (O-2 <4.6 mg L-1). Areas identified as problematic in our study were characterized by low exposure to wave forcing, high topographic shelter from surrounding areas and isolation from the open sea, all contributing to longer water residence times in seabed depressions. Deviations from this topographical background are probably caused by strong currents or high nutrient loading, thus improving or worsening oxygen status, respectively. In some areas, connectivity with adjacent deeper basins may also influence coastal oxygen dynamics. Developed models could boost the performance of biogeochemical models, aid developing nutrient abatement measures and pinpoint areas where management actions are most urgently needed.Peer reviewe

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

Substrate limitation of a habitat-forming genus Fucus under different water clarity scenarios in the northern Baltic Sea

Canopy-forming macroalgae living on rocky bottoms provide valuable ecosystem services but long-term eutrophication has narrowed their distribution and depth zonation in the Baltic Sea. The spatial distribution of macroalgae is shaped by many factors, such as light, salinity, nutrients and wave exposure. In addition, the lack of suitable hard substrates limits the distribution of algae in many areas. Analysing how the spatial distribution of macroalgae is modified by changes in environmental conditions is relevant for focusing management actions. To quantify the resultant distribution under various environmental and management scenarios, both current environmental conditions and substrate limitation need to be considered. We estimated the potential distribution area of bladderwrack Fucus spp. under 11 water transparency scenarios in 9 Finnish sea areas differing in morphology and eutrophication status. The prevailing averaged long-term water transparency conditions were interpreted from satellite images. Ten scenarios were calculated based on hypothetical changes in euphotic depth from −50% to +50% of the present. Species distribution modelling was used to assess the potential distribution areas of Fucus. In addition, to quantify the influence of substrate limitation, we estimated the average substrate limitation with two correction methods: (i) by using field data from underwater videos within the predicted distribution areas and (ii) by using a habitat model representing the distribution of reefs (i.e. rocky bottoms) in the study area. The decrease of euphotic depth by 50% from the present level narrowed the distribution area of Fucus by 24–53% in the Southwestern archipelago, 55–70% in the Gulf of Finland, 37–66% in the Bothnian Sea and 59–100% in Kvarken. An increase in euphotic depth significantly broadened the spatial distribution of Fucus. Decreasing share of suitable hard substrate along depth gradient however hinders broadening of the distribution area. If all areas were suitable for growth, a 50% increase in euphotic depth would expand the distribution area by 124–803%, depending on area. When only suitable substrates were taken into account, this percentage remained at 9–270%. We conclude that substrate limitation needs to be taken into account when estimating macroalgal species distribution in the marine environment. We show how this can be done also when comprehensive bottom substrate maps are not available. Our results are valuable when setting the targets for environmental management plans, and for balancing the local management measures in a cost effective manner. Highlights • Benthic light conditions affect the distribution of canopy-forming macroalgae Fucus. • Also substrate limits the distribution and zonation of Fucus. • Scenario modelling and substrate correction methods were utilised. • Sea areas differ in substrate composition which affects potential distribution area. • Substrate limitation is more pronounced in inner than in outer archipelago

Cormorants have negligible seascape-scale impacts on benthic vegetation communities

Cormorant populations in the Baltic Sea have rapidly expanded since the 1990s, raising concerns about their ecosystem impacts. Nutrient runoff from colonies, as well as cormorant predation on fish, can affect surrounding producer communities. Past studies have found cormorant impacts on producers in the immediate vicinity of colonies, but the importance of cormorants over a larger spatial scale is unknown, especially compared to other environmental variables. We used an extensive underwater vegetation inventory dataset (~18 000 data points along the Finnish coast) to determine the effects of cormorant colonies on macroalgae and plants. We compared community structure and species abundance/occurrence in near-colony (10 km from a colony) points, and determined the importance of cormorant influence (using an index incorporating colony size and distance from the colony) in near-colony sites. We found no significant differences in community structure between near-colony and control points in most habitats, and adding cormorant index only infinitesimally improved statistical models after incorporating other environmental factors. However, the abundance of several species did differ, in particular the foundation species bladderwrack (Fucus vesiculosus) and eelgrass (Zostera marina) were either less likely to occur in near-colony points or negatively correlated with cormorant index, possibly due to the effects of nutrient enrichment from colonies. Our findings confirm that cormorants can have effects on some producer species, but highlight that these effects are negligible when taking into account the scale and magnitude of other bottom up and top-down processes occurring in the Baltic Sea.</div

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

Physical activity and sedentary behaviour in relation to cardiometabolic risk in children: cross-sectional findings from the Physical Activity and Nutrition in Children (PANIC) Study

BACKGROUND: Lower levels of physical activity (PA) and sedentary behaviour (SB) have been associated with increased cardiometabolic risk among children. However, little is known about the independent and combined associations of PA and SB as well as different types of these behaviours with cardiometabolic risk in children. We therefore investigated these relationships among children. METHODS: The subjects were a population sample of 468 children 6–8 years of age. PA and SB were assessed by a questionnaire administered by parents and validated by a monitor combining heart rate and accelerometry measurements. We assessed body fat percentage, waist circumference, blood glucose, serum insulin, plasma lipids and lipoproteins and blood pressure and calculated a cardiometabolic risk score using population-specific Z-scores and a formula waist circumference + insulin + glucose + triglycerides - HDL cholesterol + mean of systolic and diastolic blood pressure. We analysed data using multivariate linear regression models. RESULTS: Total PA was inversely associated with the cardiometabolic risk score (β = -0.135, p = 0.004), body fat percentage (β = -0.155, p < 0.001), insulin (β = -0.099, p = 0.034), triglycerides (β = -0.166, p < 0.001), VLDL triglycerides (β = -0.230, p < 0.001), VLDL cholesterol (β = -0.168, p = 0.001), LDL cholesterol (β = -0.094, p = 0.046) and HDL triglycerides (β = -0.149, p = 0.004) and directly related to HDL cholesterol (β = 0.144, p = 0.002) adjusted for age and gender. Unstructured PA was inversely associated with the cardiometabolic risk score (β = -0.123, p = 0.010), body fat percentage (β = -0.099, p = 0.027), insulin (β = -0.108, p = 0.021), triglycerides (β = -0.144, p = 0.002), VLDL triglycerides (β = -0.233, p < 0.001) and VLDL cholesterol (β = -0.199, p < 0.001) and directly related to HDL cholesterol (β = 0.126, p = 0.008). Watching TV and videos was directly related to the cardiometabolic risk score (β = 0.135, p = 0.003), body fat percentage (β = 0.090, p = 0.039), waist circumference (β = 0.097, p = 0.033) and systolic blood pressure (β = 0.096, p = 0.039). Resting was directly associated with the cardiometabolic risk score (β = 0.092, p = 0.049), triglycerides (β = 0.131, p = 0.005), VLDL triglycerides (β = 0.134, p = 0.009), VLDL cholesterol (β = 0.147, p = 0.004) and LDL cholesterol (β = 0.105, p = 0.023). Other types of PA and SB had less consistent associations with cardiometabolic risk factors. CONCLUSIONS: The results of our study emphasise increasing total and unstructured PA and decreasing watching TV and videos and other sedentary behaviours to reduce cardiometabolic risk among children. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01803776

Increase in adiposity from childhood to adulthood predicts a metabolically obese phenotype in normal-weight adults

Normal weight is associated with a favorable cardiometabolic risk profile and low risk of type 2 diabetes and cardiovascular disease. However, some normal-weight individuals—the “metabolically obese normal weight” (MONW)—show a cardiometabolic risk profile similar to the obese. Previous studies have shown that older age, central body fat distribution, and unfavorable lifestyle increase the risk of MONW. However, the role of early-life factors in MONW remains unknown. We examined the associations of early-life factors with adult MONW in 1178 individuals from the Cardiovascular Risk in Young Finns study who were followed up from childhood to adulthood. The strongest early predictor for adult MONW was an increase in BMI from childhood to adulthood (p = 3.1 × 10−11); each 1 SD increase in BMI z-score from childhood to adulthood led to a 2.56-fold increase in the risk of adult MONW (CI 95% = 1.94–3.38). Other significant predictors of adult MONW were male sex (OR = 2.38, 95% = 1.63–3.47, p = 7.0 × 10−6), higher childhood LDL cholesterol (OR = 1.41 per 1 SD increase in LDL cholesterol, CI 95% = 1.14–1.73, p = 0.001), and lower HDL cholesterol (OR = 1.51 per 1 SD decrease in HDL cholesterol, CI 95% = 1.23–1.85, p = 5.4 × 10−5). Our results suggest that an increase in adiposity from childhood to adulthood is detrimental to cardiometabolic health, even among individuals remaining normal weight.</p