A one-season prospective study of injuries and illness in elite junior tennis
- Authors: Pluim, Babette , Loeffen, F. , Clarsen, Ben , Bahr, Roald , Verhagen, Evert
- Date: 2016
- Type: Text , Journal article
- Relation: Scandinavian Journal of Medicine and Science in Sports Vol. 26, no. 5 (2016), p. 564-571
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- Description: The objective of this study was to estimate the incidence and prevalence of injury and illness among elite junior tennis players. A cohort of 73 players (11-14 years) in the 2012-2013 Dutch national high-performance program was followed for 32 weeks; all participants completed the study. The OSTRC Questionnaire on Health Problems was used to record self-reported injuries and illnesses and to record training and match exposure. Main outcome measures were average prevalence of overuse injury and illness and incidence density of acute injury. On average, players practiced 9.1h/week (SD 0.6; range 2.3-12.0) and had 2.2h of match play (SD 0.6; range 2.3-12.0). During the course of the study, 67 players reported a total of 187 health problems. The average weekly prevalence of all health problems was 21.3% (95% CI: 19.2-22.9), of which 12.1% (95% CI: 10.9-13.3) constituted overuse injuries and 5.8% (95% CI: 4.6-6.9) illnesses. The incidence of acute injuries was 1.2/1000h of tennis play (95% CI: 0.7-1.7). The high occurrence of overuse injuries among elite junior tennis players suggests that an early focus on preventative measures is warranted, with a particular focus on the monitoring and management of workload. © 2016 John Wiley & Sons A/S.
Analysis of a severe head injury in World Cup alpine skiing
- Authors: Yamazaki, Junya , Gilgien, Matthias , Kleiven, Svein , McIntosh, Andrew , Nachbauer, Werner , Muller, Erich , Bere, Tone , Bahr, Roald , Krosshaug, Tron
- Date: 2015
- Type: Text , Journal article
- Relation: Medicine and Science in Sports and Exercise Vol. 47, no. 6 (2015), p. 1113-1118
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- Description: Traumatic brain injury (TBI) is the leading cause of death in alpine skiing. It has been found that helmet use can reduce the incidence of head injuries between 15% and 60%. However, knowledge on optimal helmet performance criteria in World Cup alpine skiing is currently limited owing to the lack of biomechanical data from real crash situations. Purpose: This study aimed to estimate impact velocities in a severe TBI case in World Cup alpine skiing. Methods: Video sequences from a TBI case in World Cup alpine skiing were analyzed using a model-based image matching technique. Video sequences from four camera views were obtained in full high-definition (1080p) format. A three-dimensional model of the course was built based on accurate measurements of piste landmarks and matched to the background video footage using the animation software Poser 4. A trunk-neck-head model was used for tracking the skier's trajectory. Results: Immediately before head impact, the downward velocity component was estimated to be 8 m.s(-1). After impact, the upward velocity was 3 m.s(-1), whereas the velocity parallel to the slope surface was reduced from 33 m.s(-1) to 22 m.s(-1). The frontal plane angular velocity of the head changed from 80 radIsj1 left tilt immediately before impact to 20 rad.s(-1) right tilt immediately after impact. Conclusions: A unique combination of high-definition video footage and accurate measurements of landmarks in the slope made possible a high-quality analysis of head impact velocity in a severe TBI case. The estimates can provide crucial information on how to prevent TBI through helmet performance criteria and design.
Head impact velocities in FIS World Cup snowboarders and freestyle skiers : Do real-life impacts exceed helmet testing standards?
- Authors: Steenstrup, Sophie , Mok, Kam-Ming , McIntosh, Andrew , Bahr, Roald , Krosshaug, Tron
- Date: 2018
- Type: Text , Journal article
- Relation: British Journal of Sports Medicine Vol. 52, no. 1 (2018), p. 32-40
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- Description: Introduction Prior to the 2013-2014 season, the International Ski Federation (FIS) increased the helmet testing speed from a minimum requirement of 5.4 to 6.8 m/s for alpine downhill, super-G and giant slalom and for freestyle ski cross, but not for the other freestyle disciplines or snowboarding. Whether this increased testing speed reflects impact velocities in real head injury situations on snow is unclear. We therefore investigated the injury mechanisms and gross head impact biomechanics in four real head injury situations among World Cup (WC) snowboard and freestyle athletes and compared these with helmet homologation laboratory test requirements. The helmets in the four cases complied with at least European Standards (EN) 1077 (Class B) or American Society for Testing and Materials (ASTM) F2040. Methods We analysed four head injury videos from the FIS Injury Surveillance System throughout eight WC seasons (2006-2014) in detail. We used motion analysis software to digitize the helmet's trajectory and estimated the head's kinematics in two dimensions, including directly preimpact and postimpact. Results All four impacts were to the occiput. In the four cases, the normal-to-slope preimpact velocity ranged from 7.0(±SD 0.2) m/s to 10.5±0.5 m/s and the normalto-slope velocity change ranged from 8.4±0.6 m/s to 11.7±0.7 m/s. The sagittal plane helmet angular velocity estimates indicated a large change in angular velocity (25.0±2.9 rad/s to 49.1±0.3 rad/s). Conclusion The estimated normal-to-slope preimpact velocity was higher than the current strictest helmet testing rule of 6.8 m/s in all four cases. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved.
Head injury mechanisms in FIS World Cup alpine and freestyle skiers and snowboarders
- Authors: Steenstrup, Sophie , Bakken, Arnhild , Bere, Tone , Patton, Declan , Bahr, Roald
- Date: 2018
- Type: Text , Journal article
- Relation: British Journal of Sports Medicine Vol. 52, no. 1 (2018), p. 61-69
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- Description: Introduction Head injuries represent a concern in skiing and snowboarding, with traumatic brain injuries being the most common cause of death. Aim To describe the mechanisms of head and face injuries among World Cup alpine and freestyle skiers and snowboarders. Methods We performed a qualitative analysis of videos obtained of head and face injuries reported through the International Ski Federation Injury Surveillance System during 10 World Cup seasons (2006-2016). We analysed 57 head impact injury videos (alpine n=29, snowboard n=13, freestyle n=15), first independently and subsequently in a consensus meeting. Results During the crash sequence, most athletes (84%) impacted the snow with the skis or board first, followed by the upper or lower extremities, buttocks/pelvis, back and, finally, the head. Alpine skiers had sideways (45%) and backwards pitching falls (35%), with impacts to the rear (38%) and side (35%) of the helmet. Freestyle skiers and snowboarders had backwards pitching falls (snowboard 77%, freestyle 53%), mainly with impacts to the rear of the helmet (snowboard 69%, freestyle 40%). There were three helmet ejections among alpine skiers (10% of cases), and 41% of alpine skiing injuries occurred due to inappropriate gate contact prior to falling. Athletes had one (47%) or two (28%) head impacts, and the first impact was the most severe (71%). Head impacts were mainly on snow (83%) on a downward slope (63%). Conclusion This study has identified several characteristics of the mechanisms of head injuries, which may be addressed to reduce risk.
No association between rate of torque development and onset of muscle activity with increased risk of hamstring injury in elite football
- Authors: van Dyk, Nicol , Bahr, Roald , Burnett, Angus , Verhagen, Evert , Von Tiggelen, D. , Witvrouw, Erik
- Date: 2018
- Type: Text , Journal article
- Relation: Scandinavian Journal of Medicine and Science in Sports Vol. 28, no. 10 (2018), p. 2153-2163
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- Description: Hamstring injuries remain a significant burden in sports that involve high-speed running. In elite male football, hamstring injury has repeatedly been identified as the most common non-contact injury, representing 12% of all injuries. As the incidence remains high, investigations are aimed at better understanding how to improve prevention efforts. Intrinsic risk factors such as strength have been investigated extensively in a cohort of professional football players; however, other intrinsic measures of neuromuscular function have not been studied in this cohort. This study aims to investigate the association between timing of hamstring muscle activity onset and the rate of torque development during the early phase of isokinetic strength testing with risk of hamstring injury in professional football players in a prospective cohort study. All teams (n = 18) eligible to compete in the premier football league in Qatar underwent a comprehensive strength assessment during their annual periodic health evaluation at Aspetar Orthopaedic and Sports Medicine Hospital in Doha, Qatar. Variables included rate of torque development and timing of muscle activity onset. A total of 367 unique players (60.6% of all QSL players) competed for 514 player seasons (103 players competed both seasons) and sustained 65 hamstring injuries. There was no difference in the onset of muscle activity between the biceps femoris and medial hamstrings comparing the injured to uninjured players. For both onset of muscle activity and rate of torque development, there were no significant differences between any of the variables (P >.05), with small effect sizes detected across all the different variables (d < 0.3). Rate of torque development and onset of muscle activity were not associated with a risk of future hamstring injury. The use of these measures as part of a periodic health evaluation to identify risk of hamstring injury is unsupported.
Reconstruction of head impacts in FIS World Cup alpine skiing
- Authors: Steenstrup, Sophie , Mok, Kam-Ming , McIntosh, Andrew , Bahr, Roald , Krosshaug, Tron
- Date: 2018
- Type: Text , Journal article
- Relation: British Journal of Sports Medicine Vol. 52, no. 11 (2018), p. 709-715
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- Description: Introduction Prior to the 2013/2014 season, the International Ski Federation (FIS) increased the helmet testing speed from 5.4 to 6.8 m/s for alpine downhill, super-G and giant slalom. Whether this increased testing speed reflects head impact velocities in real head injury situations on snow is unclear. We therefore investigated the injury mechanisms and gross head impact biomechanics in seven real head injury situations among World Cup (WC) alpine skiers. Methods We analysed nine head impacts from seven head injury videos from the FIS Injury Surveillance System, throughout nine WC seasons (2006-2015) in detail. We used commercial video-based motion analysis software to estimate head impact kinematics in two dimensions, including directly preimpact and postimpact, from broadcast video. The sagittal plane angular movement of the head was also measured using angle measurement software. Results In seven of nine head impacts, the estimated normal to slope preimpact velocity was higher than the current FIS helmet rule of 6.8 m/s (mean 8.1 (±SD 0.6) m/s, range 1.9±0.8 to 12.1±0.4 m/s). The nine head impacts had a mean normal to slope velocity change of 9.3±1.0 m/s, range 5.2±1.1 to 13.5±1.3 m/s. There was a large change in sagittal plane angular velocity (mean 43.3±2.9 rad/s (range 21.2±1.5 to 64.2±3.0 rad/s)) during impact. Conclusion The estimated normal to slope preimpact velocity was higher than the current FIS helmet rule of 6.8 m/s in seven of nine head impacts.
The IOC Centres of Excellence bring prevention to Sports Medicine
- Authors: Engebretsen, Lars , Bahr, Roald , Cook, Jill , Derman, Wayne , Emery, Carolyn , Finch, Caroline , Meeuwisse, Willem , Schwellnus, Martin , Steffen, Kathrin
- Date: 2014
- Type: Text , Journal article
- Relation: British Journal of Sports Medicine Vol. 48, no. 17 (2014), p. 1270-1275
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- Description: The protection of an athlete's health and preventing injuries and illnesses in sport are top priorities for the IOC and its Medical Commission. The IOC therefore partners with selected research centres around the world and supports research in the field of sports medicine. This has enabled the IOC to develop an international network of expert scientists and clinicians in sports injury and disease prevention research. The IOC wants to promote injury and disease prevention and the improvement of physical health of the athlete by: (1) establishing long-term research programmes on injury and disease prevention (including studies on basic epidemiology, risk factors, injury mechanisms and intervention), (2) fostering collaborative relationships with individuals, institutions and organisations to improve athletes' health, (3) implementing and collaborating with applied, ongoing and novel research and development within the framework and long-term strategy of the IOC and (4) setting up knowledge translation mechanisms to share scientific research results with the field throughout the Olympic Movement and sports community and converting these results into concrete actions to protect the health of the athletes. In 2009, the IOC also identified four research centres that had an established track record in research, educational and clinical activities to achieve these ambitions: (1) the Australian Centre for Research into Injury in Sport and its Prevention (ACRISP), Australia; (2) the Sport Injury Prevention Research Centre (SIPRC), Canada; (3) the Clinical Sport and Exercise Medicine Research (CSEM), South Africa and (4) the Oslo Sports Trauma Research Center (OSTRC), Norway. This paper highlights the work carried out by these four IOC Centres of Excellence over the past 6 years and their contribution to the world of sports medicine.
Towards the reduction of injury and illness in athletes : Defining our research priorities
- Authors: Finch, Caroline , Bahr, Roald , Drezner, Jonathan , Dvorak, Jiri , Engebretsen, Lars , Hewett, Timothy , Junge, Astrid , Khan, Karim , Macauley, Domhnall , Matheson, Gordon , McCrory, Paul , Verhagen, Evert
- Date: 2017
- Type: Text , Journal article , Review
- Relation: British Journal of Sports Medicine Vol. 51, no. 16 (2017), p. 1178-1182
- Relation: http://purl.org/au-research/grants/nhmrc/1058737
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