Aim: The aim of the present study was to determine the validity of position, distance traveled and instantaneous speed of team sport players as measured by a commercially available local positioning system (LPS) during indoor use. In addition, the study investigated how the placement of the field of play relative to the anchor nodes and walls of the building affected the validity of the system.Method: The LPS (Catapult ClearSky T6, Catapult Sports, Australia) and the reference system [Qualisys Oqus, Qualisys AB, Sweden, (infra-red camera system)] were installed around the field of play to capture the athletes' motion. Athletes completed five tasks, all designed to imitate team-sports movements. The same protocol was completed in two sessions, one with an assumed optimal geometrical setup of the LPS (optimal condition), and once with a sub-optimal geometrical setup of the LPS (sub-optimal condition). Raw two-dimensional position data were extracted from both the LPS and the reference system for accuracy assessment. Position, distance and speed were compared.Results: The mean difference between the LPS and reference system for all position estimations was 0.21 ± 0.13 m (n = 30,166) in the optimal setup, and 1.79 ± 7.61 m (n = 22,799) in the sub-optimal setup. The average difference in distance was below 2% for all tasks in the optimal condition, while it was below 30% in the sub-optimal condition. Instantaneous speed showed the largest differences between the LPS and reference system of all variables, both in the optimal (≥35%) and sub-optimal condition (≥74%). The differences between the LPS and reference system in instantaneous speed were speed dependent, showing increased differences with increasing speed.Discussion: Measures of position, distance, and average speed from the LPS show low errors, and can be used confidently in time-motion analyses for indoor team sports. The calculation of instantaneous speed from LPS raw data is not valid. To enhance instantaneous speed calculation the application of appropriate filtering techniques to enhance the validity of such data should be investigated. For all measures, the placement of anchor nodes and the field of play relative to the walls of the building influence LPS output to a large degree.

This file was downloaded from the institutional repository Brage NIH -brage.bibsys.no/nih Luteberget, L. S., Spencer, M. (2017 Abstract:International female team handball is a physically demanding sport and is intermittent in nature.The aim of the study was to profile high intensity events (HIE) in international female team handball matches, with regards to playing positions. Methods: Twenty female national team handball players were equipped with inertial movement units (OptimEye S5, Catapult Sports, Australia) in 9 official international matches. Players were categorized in four different playing positions: backs, wings, pivots, and goalkeepers (GK). Player Load™, accelerations (Acc), changes of direction (CoD), decelerations (Dec), and the sum of the latter three, HIE, were extracted from data raw-files, using the manufacture's software. All Acc, Dec, CoD, and HIE >2.5 m·s -1 were included. Data were log-transformed and differences were standardized for interpretation of magnitudes and reported with effect size (ES) statistic. Results: Mean number of events was 0.7 ± 0.4 Acc·min -1 , 2.3 ± 0.9 Dec·min -1 , and 1.0 ± 0.4 CoD·min -1 . Substantial differences between playing positions, ranging from small to very large, were found in the three parameters. Backs showed a most likely greater frequency for HIE·min -1 (5.0 ± 1.1 HIE·min -1 ), than all other playing positions. Differences between playing positions was also apparent in Player Load·min -1 . Conclusion: The present study shows that HIE in international female team handball are position specific, and that the overall intensity is dependent on the positional role within a team. Specific HIE and intensity profiles from match play provide useful information for a better understanding of the overall game demands and for each playing position.

Dette er siste tekst-versjon av artikkelen, og den kan inneholde små forskjeller fra forlagets pdf-versjon. Forlagets pdf-versjon finner du på journals.humankinetics.com: http://dx.doi.org/10. 1123/ijspp.2015-0732 This is the final text version of the article, and it may contain minor differences from the journal's pdf version. profiles. Activity levels were substantially lower in the five minutes after a player's most intense period, and were partly restored in the subsequent 5-minute period. Discussion:Possible explanations for the observed declines in activity profiles for the team and individual players include fatiguing players, situational factors and pacing. However, underlying mechanisms were not accounted for, and these assumptions are therefore based on previous team-sport studies.

Many elite sport organisations have introduced structured talent identification and development (TID) initiatives in youth sports to better facilitate elite sport performance. However, selection mechanisms for TID programmes (e.g., junior international team) are biased towards relatively older athletes and limited studies exist with Scandinavian contexts. Therefore, the aim of this study was to explore the relative age effect (RAE) in youth, junior and senior male and female international team selections among Norwegian handball players (n = 657). A Chi-square goodness-of-fit test assessed whether a skewed birthdate distribution occurred at the youth, junior and senior international team levels and odds-ratios were calculated for RAE distribution. Moreover, a Kruskal-Wallis test was used to assess differences between the number of international youth, junior and senior level appearances by birth quartiles. Significant uneven birth date distributions were shown for youth (χ2(7) = female 40.383 and male 105.716, p <0.001) and junior (χ2(7) = female 27.427 and male 30.948, p <0.001) international players, favouring the relatively older player (odds-ratio of 1.9–8.3). At the senior level, no uneven distribution was identified. The comparison of the number of matches in each age category and the quartile of birth showed a difference in the women’s youth category, where players in quartile 8 had a significantly lower number of appearances compared to quartile 1. The results form part of a growing body of knowledge about selection mechanisms in sport, which favours relatively older athletes within Norwegian Handball. Such findings are important for policy and practice for informing TID programmes for inclusive selection opportunities for all players.

The reliability of IMA counts was good when data were displayed as total, high, or medium/high counts. A good reliability for PlayerLoad and associated variables was evident. The CV of the previously mentioned variables was well below the SWD, suggesting that OptimEye's inertial measurement unit and its software are sensitive for use in team handball.