Player-to-player contact inherent in many unhelmeted sports means that head impacts are a frequent occurrence. Model-Based Image-Matching (MBIM) provides a technique for the assessment of three-dimensional linear and rotational motion patterns from multiple camera views of a head impact event, but the accuracy is unknown for this application. The goal of this study is to assess the accuracy of the MBIM method relative to reflective marker-based motion analysis data for estimating six degree of freedom head displacements and velocities in a staged pedestrian impact scenario at 40 km/h. Results showed RMS error was under 20 mm for all linear head displacements and 0.01–0.04 rad for head rotations. For velocities, the MBIM method yielded RMS errors between 0.42 and 1.29 m/s for head linear velocities and 3.53–5.38 rad/s for angular velocities. This method is thus beneficial as a tool to directly measure six degree of freedom head positional data from video of sporting head impacts, but velocity data is less reliable. MBIM data, combined in future with velocity/acceleration data from wearable sensors could be used to provide input conditions and evaluate the outputs of multibody and finite element head models for brain injury assessment of sporting head impacts. 相似文献
Background: There is a high incidence of concussion sustained by athletes participating in rugby union, many of which go unreported. A lack of sufficient knowledge about concussion injuries may explain athletes’ failure to report. Several rugby union-playing countries have developed injury education and prevention programmes to address this issue. Objective: The aim of the current review was to systematically assess the content and level of evidence on concussion education/prevention programmes in rugby union and to make recommendations for the quality, strength, and consistency of this evidence. Methods: We searched PubMed, PsycInfo, MEDLINE, SPORTDiscuss, Webofscience, and conducted a manual search for articles. Results: Ten articles were included for review. Of these, six focused on the BokSmart injury prevention programme in South Africa, two focused on the RugbySmart injury prevention programme in New Zealand, one was an analysis of prevention programmes, and one was a systematic review of rugby injury prevention strategies. Conclusions: Despite the initiative to develop concussion education and prevention programmes, there is little evidence to support the effectiveness of such programmes. There is evidence to support education of coaches and referees. In addition, there is scant evidence to suggest that education and rule changes may have the benefit of changing athlete behaviours resulting in a reduction in catastrophic injury. 相似文献
Rugby union is a sport governed by the impacts of high force and high frequency. Analysis of physiological markers following a game can provide an understanding of the physiological response of an individual and the time course changes in response to recovery.
Urine and saliva were collected from 11 elite amateur rugby players 24 h before, immediately after, and at 17, 25, 38, 62 and 86 h post-game. Myoglobin, salivary immunoglobulin A and cortisol were analysed by ELISA, whereas neopterin and total neopterin were analysed by high-performance liquid chromatography.
There was a significant post-game increase of all four markers. The increases were cortisol 4-fold, myoglobin 2.85-fold, neopterin 1.75-fold and total neopterin 2.3-fold when corrected with specific gravity. All significant changes occurred post-game only, with markers returning to and remaining at baseline within 17 h.
The intensity of the game caused significant changes in key physiological markers of stress. They provide an understanding of the stress experienced during a single game of rugby and the time course changes associated with player recovery. Neopterin provides a new marker of detecting an acute inflammatory response in physical exercise, while specific gravity should be considered for urine volume correction post-exercise. 相似文献
Abstract This study examined the consistency of pre-performance routines in international rugby union goal kickers on kicks of varying difficulty and under different amounts of situational pressure. Concentration times and physical preparation times were calculated from video recordings of the 572 place kicks taken during the 1999 Rugby Union World Cup. In contrast to the view that performers should seek consistent pre-performance routine times, the results revealed a strong positive relationship between kick difficulty and concentration time. Analysis of the effect of situational pressure, determined by the difference in score before the kick, revealed that players tended to have longer concentration times and shorter physical preparation times when the scores were close. There were no differences between the best and worst kickers in the tournament on routine time, consistency or rhythmicity. The view that increasing the temporal consistency of a routine will result in improved performance is challenged. 相似文献
The subjects were 31 successful schoolboy rugby players and 25 successful schoolboy hurlers; 34 non‐team members acted as controls. Thirty‐one anthropometric measurements were taken on each subject: height, weight, sitting height, five skeletal lengths, six skeletal diameters, 13 muscle circumferences and four skinfolds. The non‐players were significantly smaller than both the rugby players and the hurlers in weight, biacromial diameter, bideltoid, neck, chest, flexed arm, upper and lower thigh and calf circumferences. The non‐players were significantly smaller than the rugby players in arm length, femur diameter and waist, hip and relaxed arm circumferences. The non‐players were significantly smaller than the hurlers in femur length, biiliac and ankle diameters. There were no statistically significant differences between the rugby players and hurlers. Discriminant analysis produced a function containing terms for height, weight, fat free weight, humerus diameter and neck, bideltoid, forearm and calf circumferences which correctly assigned 83 (92%) of the subjects to ‘player’ and ‘non‐player’ categories. When the function was applied to the 15 members of the rugby team of a different school, 14 were placed in the ‘player’ category and one subject was given a borderline classification. It is concluded that there were differences in physique between the team members and non‐members and that the techniques used in the study were effective in quantifying them. 相似文献