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.
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.
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.
Radial and oblique impact testing of alpine helmets onto snow surfaces
- Authors: Patton, Declan , Mohammadi, Reza , Halldin, Peter , Kleiven, Svein , McIntosh, Andrew
- Date: 2023
- Type: Text , Journal article
- Relation: Applied Sciences (Switzerland) Vol. 13, no. 6 (2023), p.
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- Description: Recent studies have found that alpine helmets reduce the risk of focal injuries associated with radial impacts, which is likely due to current alpine helmet standards requiring helmets to be drop-tested on flat anvils with only linear acceleration pass criteria. There is a need to evaluate the performance of alpine helmets in more realistic impacts. The current study developed a method to assess the performance of alpine helmets for radial and oblique impacts on snow surfaces in a laboratory setting. Snow samples were collected from a groomed area of a ski slope. Radial impacts were performed as drop tests onto a stationary snow sample. Oblique impacts were performed as drop tests onto a snow sample moving horizontally. For radial impacts, snow sample collection time was found to significantly (p = 0.005) influence mean peak linear headform acceleration with an increase in ambient temperature softening the snow samples. For oblique tests, the recreational alpine sports helmet with a rotation-damping system (RDS) significantly (p = 0.002) reduced mean peak angular acceleration compared to the same helmets with no RDS by approximately 44%. The ski racing helmet also significantly (p = 0.006) reduced mean peak angular acceleration compared to the recreational alpine sports helmet with no RDS by approximately 33%, which was attributed to the smooth outer shell of the ski racing helmet. The current study helps to bridge the knowledge gap between real helmet impacts on alpine snow slopes and laboratory helmet impacts on rigid surfaces. © 2023 by the authors.
Combining epidemiology and biomechanics in sports injury prevention research : A new approach for selecting suitable controls
- Authors: Finch, Caroline , Ullah, Shahid , McIntosh, Andrew
- Date: 2011
- Type: Text , Journal article
- Relation: Sports Medicine Vol. 41, no. 1 (2011), p. 59-72
- Relation: http://purl.org/au-research/grants/nhmrc/565900
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- Description: Several important methodological issues need to be considered when designing sports injury case-control studies. Major design goals for case-control studies include the accounting for prior injury risk exposure, and optimal definitions of both cases and suitable controls are needed to ensure this. This article reviews methodological aspects of published sports injury case-control studies, particularly with regard to the selection of controls. It argues for a new approach towards selecting controls for case-control studies that draws on an interface between epidemiological and biomechanical concepts. A review was conducted to identify sport injury case-control studies published in the peer-review literature during 1985-2008. Overall, 32 articles were identified, of which the majority related to upper or lower extremity injuries. Matching considerations were used for control selection in 16 studies. Specific mention of application of biomechanical principles in the selection of appropriate controls was absent from all studies, including those purporting to evaluate the benefits of personal protective equipment to protect against impact injury. This is a problem because it could lead to biased conclusions, as cases and controls are not fully comparable in terms of similar biomechanical impact profiles relating to the injury incident, such as site of the impact on the body. The strength of the conclusions drawn from case-control studies, and the extent to which results can be generalized, is directly influenced by the definition and recruitment of cases and appropriate controls. Future studies should consider the interface between epidemiological and biomechanical concepts when choosing appropriate controls to ensure that proper adjustment of prior exposure to injury risk is made. To provide necessary guidance for the optimal selection of controls in case-control studies of interventions to prevent sports-related impact injury, this review outlines a new case-control selection strategy that reflects the importance of biomechanical considerations, which ensures that controls are selected based on the presence of the same global injury mechanism as the cases. To summarize, the general biomechanical principles that should apply to the selection of controls in future case-control studies are as follows: (i) each control must have been exposed to the same global injury mechanism as the case, (e.g. head impact, fall onto outstretched arm); and (ii) intrinsic (individual) factors (e.g. age, sex, skill level) that might modify the person's response to the relevant biomechanical loads are adjusted when either selecting the controls or are in the analysis phase. The same considerations for control selection apply to other study designs such as matched cohort studies or case-crossover studies. © 2011 Adis Data Information BV. All rights reserved.
Collecting health and exposure data in Australian olympic combat sports : Feasibility study utilizing an electronic system
- Authors: Bromley, Sally , Drew, Michael , Talpey, Scott , McIntosh, Andrew , Finch, Caroline
- Date: 2018
- Type: Text , Journal article
- Relation: Journal of Medical Internet Research Vol. 20, no. 10 (2018), p. 1-11
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- Description: Background: Electronic methods are increasingly being used to manage health-related data among sporting populations. Collection of such data permits the analysis of injury and illness trends, improves early detection of injuries and illnesses, collectively referred to as health problems, and provides evidence to inform prevention strategies. The Athlete Management System (AMS) has been employed across a range of sports to monitor health. Australian combat athletes train across the country without dedicated national medical or sports science teams to monitor and advocate for their health. Employing a Web-based system, such as the AMS, May provide an avenue to increase the visibility of health problems experienced by combat athletes and deliver key information to stakeholders detailing where prevention programs May be targeted. Objective: The objectives of this paper are to (1) report on the feasibility of utilizing the AMS to collect longitudinal injury and illness data of combat sports athletes and (2) describe the type, location, severity, and recurrence of injuries and illnesses that the cohort of athletes experience across a 12-week period. Methods: We invited 26 elite and developing athletes from 4 Olympic combat sports (boxing, judo, taekwondo, and wrestling) to participate in this study. Engagement with the AMS was measured, and collected health problems (injuries or illnesses) were coded using the Orchard Sports Injury Classification System (version 10.1) and International Classification of Primary Care (version 2). Results: Despite >160 contacts, athlete engagement with online tools was poor, with only 13% compliance across the 12-week period. No taekwondo or wrestling athletes were compliant. Despite low overall engagement, a large number of injuries or illness were recorded across 11 athletes who entered data—22 unique injuries, 8 unique illnesses, 30 recurrent injuries, and 2 recurrent illnesses. The most frequent injuries were to the knee in boxing (n=41) and thigh in judo (n=9). In this cohort, judo players experienced more severe, but less frequent, injuries than boxers, yet judo players sustained more illnesses than boxers. In 97.0% (126/130) of cases, athletes in this cohort continued to train irrespective of their health problems. Conclusions: Among athletes who reported injuries, many reported multiple conditions, indicating a need for health monitoring in Australian combat sports. A number of factors May have influenced engagement with the AMS, including access to the internet, the design of the system, coach views on the system, previous experiences with the system, and the existing culture within Australian combat sports. To increase engagement, there May be a requirement for sports staff to provide relevant feedback on data entered into the system. Until the Barriers are addressed, it is not feasible to implement the system in its current form across a larger cohort of combat athletes.
Associations between helmet use and brain injuries amongst injured pedal- and motor-cyclists: A case series analysis of trauma centre presentations
- Authors: McIntosh, Andrew , Curtis, Kate , Rankin, Tiffany , Cox, Marie , Pang, Toh Yen , McCrory, Paul , Finch, Caroline
- Date: 2013
- Type: Text , Journal article
- Relation: Journal of the Australasian College of Road Safety Vol. 24, no. 2 (April 2013), p. 11-20
- Relation: http://purl.org/au-research/grants/nhmrc/565900
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- Description: Abstract: A retrospective case-series study of pedal- and motorcyclists presenting to a major metropolitan trauma centre over an 18 month period was undertaken. The injury data were coded according to a number of outcome variables, including intracranial injury of AIS severity >/= 2. Helmet use was coded. After stratification by rider type, data were analysed to examine the relationships between helmet use and injury using logistic regression. A total of 220 injured motorcycle riders and 137 injured pedal cyclists met the study's inclusion criteria, with 195 motorcycle riders and passengers (88.6%) and 87 pedal cyclists (63.5%) wearing helmets. Helmets were associated with a significant reduction (p<0.05) in the likelihood of head and intracranial injury in both rider groups. Associated with helmet use was a reduction in intracranial injury likelihood of 66% for both helmeted motorcycle riders and pedal cyclists. The study is further evidence of the benefits offered by helmets.
What is the definition of sports-related concussion : A systematic review
- Authors: McCrory, Paul , Feddermann-Demont, Nina , Dvorak, Jiri , Cassidy, David , McIntosh, Andrew , Vos, Pieter , Echemendia, Ruben , Meeuwisse, Willem , Tarnutzer, Alexander
- Date: 2017
- Type: Text , Journal article , Review
- Relation: British Journal of Sports Medicine Vol. 51, no. 11 (2017), p. 877-887
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- Description: Objectives: Various definitions for concussion have been proposed, each having its strengths and weaknesses. We reviewed and compared current definitions and identified criteria necessary for an operational definition of sports-related concussion (SRC) in preparation of the 5th Concussion Consensus Conference (Berlin, Germany). We also assessed the role of biomechanical studies in informing an operational definition of SRC. Design: This is a systematic literature review. Data sources: Data sources include MEDLINE, Embase, Cumulative Index to Nursing and Allied Health Literature, Cochrane Central Register of Clinical Trials and SPORT Discus (accessed 14 September 2016). Eligibility criteria for selecting studies: Eligibility criteria were studies reporting (clinical) criteria for diagnosing SRC and studies containing SRC impact data. Results: Out of 1601 articles screened, 36 studies were included (2.2%), 14 reported on criteria for SRC definitions and 22 on biomechanical aspects of concussions. Six different operational definitions focusing on clinical findings and their dynamics were identified. Biomechanical studies were obtained almost exclusively on American football players. Angular and linear head accelerations linked to clinically confirmed concussions demonstrated considerable individual variation. Summary/conclusions: SRC is a traumatic brain injury that is defined as a complex pathophysiological process affecting the brain, induced by biomechanical forces with several common features that help define its nature. Limitations identified include that the current criteria for diagnosing SRC are clinically oriented and that there is no gold/standard to assess their diagnostic properties. A future, more valid definition of SRC would better identify concussed players by demonstrating high predictive positive/negative values. Currently, the use of helmet-based systems to study the biomechanics of SRC is limited to few collision sports. New approaches need to be developed to provide objective markers for SRC. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved.
Manual handling in aged care : Impact of environment-related interventions on mobility
- Authors: Coman, Robyn , Caponecchia, Carlo , McIntosh, Andrew
- Date: 2018
- Type: Text , Journal article , Review
- Relation: Safety and Health at Work Vol. 9, no. 4 (2018), p. 372-380
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- Description: The manual handling of people (MHP) is known to be associated with high incidence of musculoskeletal disorders for aged care staff. Environment-related MHP interventions, such as appropriate seated heights to aid sit-to-stand transfers, can reduce staff injury while improving the patient’s mobility. Promoting patient mobility within the manual handling interaction is an endorsed MHP risk control intervention strategy. This article provides a narrative review of the types of MHP environmental controls that can improve mobility, as well as the extent to which these environmental controls are considered in MHP risk management and assessment tools. Although a range of possible environmental interventions exist, current tools only consider these in a limited manner. Development of an assessment tool that more comprehensively covers environmental strategies in MHP risk management could help reduce staff injury and improve resident mobility through auditing existing practices and guiding the design of new and refurbished aged care facilities.
The effects of low arched feet on lower limb gait kinematics in children
- Authors: Twomey, Dara , McIntosh, Andrew
- Type: Text , Journal article
- Relation: Foot Vol.22, no. (2), p.60-65
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- Description: Background: The effects of foot posture on the dynamic function of the lower limb during gait remains relatively unknown. Objectives: The purpose of this study was to investigate lower limb kinematics between the normal and low arched foot during the gait cycle, particularly in the transverse plane. Method: Twenty-four children, twelve with normal and twelve with low arched feet, aged 11-12 years underwent a lower limb three dimensional gait analysis. Temporo-spatial parameters and patterns and ranges of motion of kinematic data were examined for the pelvis, hip, knee and ankle throughout the gait cycle. Results: Overall, there were very few differences found in the kinematics of the lower limbs between the normal and low arched group. Increased external hip rotation (6-7°) in the low arched group was the only bilateral significant difference (p < 0.05) between the two foot groups. No significant differences existed in any temporo-spatial parameters between the two groups. Conclusions: The increased external hip rotation and greater external foot progression angle in the low arched foot highlights the need to examine gait comprehensively to establish cause or effect of these differences observed and hence determine appropriate treatment. © 2011 Elsevier Ltd. All rights reserved.
An assessment of the utility and functionality of wearable head impact sensors in Australian Football
- Authors: McIntosh, Andrew , Willmott, Catherine , Patton, Declan , Mitra, Biswadev , Brennan, James , Dimech-Betancourt, Bleydy , Howard, Teresa , Rosenfeld, Jeffrey
- Date: 2019
- Type: Text , Journal article
- Relation: Journal of Science and Medicine in Sport Vol. 22, no. 7 (2019), p. 784-789
- Full Text: false
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- Description: Objectives: To assess the utility and functionality of the X-Patch® as a measurement tool to study head impact exposure in Australian Football. Accuracy, precision, reliability and validity were examined. Designs: Laboratory tests and prospective observational study. Methods: Laboratory tests on X-Patch® were undertaken using an instrumented Hybrid III head and neck and linear impactor. Differences between X-Patch® and reference data were analysed. Australian Football players wore the X-Patch® devices and games were video-recorded. Video recordings were analysed qualitatively for head impact events and these were correlated with X-Patch® head acceleration events. Wearability of the X-Patch® was assessed using the Comfort Rating Scale for Wearable Computers. Results: Laboratory head impacts, performed at multiple impact sites and velocities, identified significant correlations between headform-measured and device-measured kinematic parameters (p < 0.05 for all). On average, the X-Patch®-recorded peak linear acceleration (PLA) was 17% greater than the reference PLA, 28% less for peak rotational acceleration (PRA) and 101% greater for the Head Injury Criterion (HIC). For video analysis, 118 head acceleration events (HAE) were included with PLA ≥30 g across 53 players. Video recordings of X-Patch®-measured HAEs (PLA ≥30 g) determined that 31.4% were direct head impacts, 9.3% were indirect impacts, 44.1% were unknown or unclear and 15.3% were neither direct nor indirect head impacts. The X-Patch® system was deemed wearable by 95–100% of respondents. Conclusions: This study reinforces evidence that use of the current X-Patch® devices should be limited to research only and in conjunction with video analysis.
Does padded headgear prevent head injury in rugby union football?
- Authors: McIntosh, Andrew , McCrory, Paul , Finch, Caroline , Best, John , Chalmers, David , Wolfe, Rory
- Date: 2009
- Type: Text , Journal article
- Relation: Medicine and Science in Sports and Exercise Vol. 41, no. 2 (2009), p. 306-313
- Relation: http://purl.org/au-research/grants/nhmrc/565900
- Full Text: false
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- Description: BACKGROUND: Concussion is a serious problem in many contact sports, including rugby union football. The study's primary aim was to measure the efficacy of padded headgear in reducing the rates of head injury or concussion. METHODS: A cluster randomized controlled trial with three arms was conducted with rugby union football teams as the unit of randomization. Teams consisted of males participating in under 13-, 15-, 18-, and 20-yr age group competitions. The interventions were "standard" and "modified" padded headgear. Headgear wearing and injury were measured for each study team at each game over two seasons. RESULTS: Eighty-two teams participated in year 1 and 87 in year 2. A total of 1493 participants (10,040 player hours) were in the control group, 1128 participants (8170 player hours) were assigned to the standard headgear group, and 1474 participants (10,650 player hours) were assigned to the modified headgear group. The compliance rates were low in all groups, but 46% of participants wore standard headgear. An intention-to-treat analysis showed no differences in the rates of head injury or concussion between controls and headgear arms. Incidence rate ratios for standard headgear wearers referenced to controls were 0.95 and 1.02 for game and missed game injuries. Analyses of injury rates based on observed wearing patterns also showed no significant differences. Incidence rate ratios for standard headgear wearers referenced to nonwearers were 1.11 and 1.10 for game and missed game injuries. CONCLUSIONS: Padded headgear does not reduce the rate of head injury or concussion. The low compliance rates are a limitation. Although individuals may choose to wear padded headgear, the routine or mandatory use of protective headgear cannot be recommended. © 2009 by the American College of Sports Medicine.
- Description: 2003008190
Head, face and neck injury in youth rugby: Incidence and risk factors
- Authors: McIntosh, Andrew , McCrory, Paul , Finch, Caroline , Wolfe, Rory
- Date: 2010
- Type: Text , Journal article
- Relation: British Journal of Sports Medicine Vol. 44, no. 3 (2010), p. 188-193
- Relation: http://purl.org/au-research/grants/nhmrc/565900
- Full Text: false
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- Description: OBJECTIVES: In this study, the incidence of head, neck and facial injuries in youth rugby was determined, and the associated risk factors were assessed. DESIGN: Data were extracted from a cluster randomised controlled trial of headgear with the football teams as the unit of randomisation. No effect was observed for headgear use on injury rates, and the data were pooled. SETTING: General school and club-based community competitive youth rugby in the 2002 and 2003 seasons. PARTICIPANTS: Young male rugby union football players participating in under-13, under 15, under 18 and under 21 years competitions. Eighty-two teams participated in year 1 and 87 in year 2. MAIN OUTCOME MEASURES: Injury rates for all body regions combined, head, neck and face calculated for game and missed game injuries. RESULTS: 554 head, face and neck injuries were recorded within a total of 28 902 h of rugby game exposure. Level of play and player position were related to injury risk. Younger players had the lowest rates of injury; forwards, especially the front row had the highest rate of neck injury; and inside backs had the highest rate of injuries causing the player to miss a game. Contact events, including the scrum and tackle, were the main events leading to injury. CONCLUSION: Injury prevention must focus on the tackle and scrum elements of a youth rugby game.
Use of field-based tests to identify risk factors for injury to fast bowlers in cricket
- Authors: Dennis, Rebecca , Finch, Caroline , McIntosh, Andrew , Elliott, Bruce
- Date: 2008
- Type: Text , Journal article
- Relation: British Journal of Sports Medicine Vol. 42, no. 6 (Jun 2008), p. 477-482
- Full Text: false
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- Description: Objective: To identify risk factors for injury to cricket fast bowlers using field-based tests. Design: Prospective cohort study. Setting: High performance Australian cricket. Participants: Ninety-one male adolescent and adult fast bowlers (aged 12-33 years). Assessment of risk factors: A field-based pre-participation screening, consisting of musculoskeletal, fitness and anthropometric assessments and analysis of bowling technique was undertaken. Bowlers were prospectively monitored over the 2003-4 season and bowling workload and injuries were recorded. Logistic regression was used to identify injury risk factors. Main outcome measurement: Repetitive microtrauma injury to the trunk, back or lower limb associated with fast bowling. Results: Two variables were identified as independent predictors of injury in the multivariate logistic regression analysis. Bowlers with hip internal rotation of <= 30 degrees on the leg ipsilateral to the bowling arm were at a significantly reduced risk of injury (OR 0.20, 95% CI 0.06 to 0.73) compared with bowlers with >40 degrees of rotation. Bowlers with an ankle dorsiflexion lunge of 12.1-14.0 cm on the leg contralateral to the bowling arm were at a significantly increased risk (OR 4.03, 95% CI 1.07 to 15.21) than bowlers with a lunge of >14 cm. Bowlers with a lunge of (12 cm were also at an increased risk, but not significantly so (OR 1.38, 95% CI 0.40 to 4.84). Conclusions: Biomechanical research is needed to investigate how these two intrinsic risk factors increase injury risk so that appropriate interventions can be developed.
SCAT3 changes from baseline and associations with X2 Patch measured head acceleration in amateur Australian football players
- Authors: Willmott, Catherine , McIntosh, Andrew , Howard, Teresa , Mitra, Biswadev , Dimech-Betancourt, Bleydy , Donovan, Jarrod , Rosenfeld, Jeffrey
- Date: 2018
- Type: Text , Journal article
- Relation: Journal of Science and Medicine in Sport Vol. 21, no. 5 (2018), p. 442-446
- Full Text: false
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- Description: Objectives: To investigate changes from baseline on SCAT3 as a result of football game exposure, and association with X2 Patch measured head acceleration events in amateur Australian footballers. Design: Prospective cohort. Methods: Peak linear acceleration (PLA) of the head (>10 g) was measured by wearable head acceleration sensor X2 Biosystems X-Patch in male (n = 34) and female (n = 19) Australian footballers. SCAT3 was administered at baseline (B) and post-game (PG). Results: 1394 head acceleration events (HEA) >10 g were measured. Mean and median HEA PLA were recorded as 15.2 g (SD = 9.2, range = 10.0–115.8) and 12.4 g (IQR = 11.0–15.6) respectively. No significant difference in median HEA PLA (g) was detected across gender (p = 0.55), however, more HEAs were recorded in males (p = 0.03). A greater number (p = 0.004) and severity (p < 0.001) of symptoms were reported PG than at B. No significant association between number of HEA or median PLA, and SCAT3 change scores (p > 0.05 for all), was identified for either gender. Conclusions: Increase in symptom severity post game was not associated with X2 measured HEA. Males sustained more HEA, however HEA PLA magnitude did not differ across gender. Further work on the validation of head acceleration sensors is required and their role in sports concussion research and medical management. © 2017 Sports Medicine Australia
The biomechanics of concussion in unhelmeted football players in Australia: A case-control study
- Authors: McIntosh, Andrew , Patton, Declan , Fréchède, Bertrand , Pierré, Paul-André , Ferry, Edouard , Barthels, Tobias
- Date: 2014
- Type: Text , Journal article
- Relation: BMJ Open Vol. 4, no. 5 (2014), p.
- Full Text: false
- Reviewed:
- Description: Objective: Concussion is a prevalent brain injury in sport and the wider community. Despite this, little research has been conducted investigating the dynamics of impacts to the unprotected human head and injury causation in vivo, in particular the roles of linear and angular head acceleration. Setting: Professional contact football in Australia. Participants: Adult male professional Australian rules football players participating in 30 games randomly selected from 103 games. Cases selected based on an observable head impact, no observable symptoms (eg, loss-of-consciousness and convulsions), no on-field medical management and no injury recorded at the time. Primary and secondary outcome measures: A data set for no-injury head impact cases comprising head impact locations and head impact dynamic parameters estimated through rigid body simulations using the MAthematical DYnamic MOdels (MADYMO) human facet model. This data set was compared to previously reported concussion case data. Results: Qualitative analysis showed that the head was more vulnerable to lateral impacts. Logistic regression analyses of head acceleration and velocity components revealed that angular acceleration of the head in the coronal plane had the strongest association with concussion; tentative tolerance levels of 1747 rad/s2 and 2296 rad/s2 were reported for a 50% and 75% likelihood of concussion, respectively. The mean maximum resultant angular accelerations for the concussion and no-injury cases were 7951 rad/s2 (SD 3562 rad/s2) and 4300 rad/s2 (SD 3657 rad/s2), respectively. Linear acceleration is currently used in the assessment of helmets and padded headgear. The 50% and 75% likelihood of concussion values for resultant linear head acceleration in this study were 65.1 and 88.5 g, respectively. Conclusions: As hypothesised by Holbourn over 70 years ago, angular acceleration plays an important role in the pathomechanics of concussion, which has major ramifications in terms of helmet design and other efforts to prevent and manage concussion.
The biomechanical determinants of concussion : Finite element simulations to investigate tissue-level predictors of injury during sporting impacts to the unprotected head
- Authors: Patton, Declan , McIntosh, Andrew , Kleiven, Svein
- Date: 2015
- Type: Text , Journal article
- Relation: Journal of Applied Biomechanics Vol. 31, no. 4 (2015), p. 264-268
- Full Text: false
- Reviewed:
- Description: Biomechanical studies of concussions have progressed from qualitative observations of head impacts to physical and numerical reconstructions, direct impact measurements, and finite element analyses. Supplementary to a previous study, which investigated maximum principal strain, the current study used a detailed finite element head model to simulate unhelmeted concussion and no-injury head impacts and evaluate the effectiveness of various tissue-level brain injury predictors: strain rate, product of strain and strain rate, cumulative strain damage measure, von Mises stress, and intracranial pressure. Von Mises stress was found to be the most effective predictor of concussion. It was also found that the thalamus and corpus callosum were brain regions with strong associations with concussion. Tentative tolerance limits for tissue-level predictors were proposed in an attempt to broaden the understanding of unhelmeted concussions. For the thalamus, tolerance limits were proposed for a 50% likelihood of concussion: 2.24 kPa, 24.0 s-1, and 2.49 s-1 for von Mises stress, strain rate, and the product of strain and strain rate, respectively. For the corpus callosum, tolerance limits were proposed for a 50% likelihood of concussion: 3.51 kPa, 25.1 s-1, and 2.76 s-1 for von Mises stress, strain rate, and the product of strain and strain rate, respectively. © 2015 Human Kinetics, Inc.
Factors affecting motorcycle helmet use: Size selection, stability, and position
- Authors: Thai, Kim , McIntosh, Andrew , Pang, Toh Yen
- Date: 2015
- Type: Text , Journal article
- Relation: Traffic Injury Prevention Vol. 16, no. 3 (2015), p. 276-282
- Full Text: false
- Reviewed:
- Description: Methods: Observations and measurements of head dimensions, helmet position, adjustment, and stability were made on 216 motorcyclists. Helmet details were recorded. Participants completed a questionnaire on helmet usability and their riding history. Helmet stability was assessed quasistatically. Results: Differences between the dimensions of ISO headforms and equivalent sized motorcyclists’ heads were observed, especially head width. Almost all (94%) of the helmets were labeled to be compliant with AS/NZS 1698 (2006). The majority of riders were satisfied with the comfort, fit, and usability aspects of their helmets. The majority of helmets were deemed to have been worn correctly. Using quasistatic pull tests, it was found that helmet type (open-face or full-face) and the wearing correctness were among factors that affected the loads at which helmets became displaced. The forces required to displace the helmet were low, around 25 N. Conclusions: The size of the in-use motorcycle helmets did not correspond well to the predicted size based on head dimensions, although motorcyclists were generally satisfied with comfort and fit. The in vivo stability tests appear to overpredict that helmets will come off in a crash, based on the measured forces, tangential forces measured in the oblique impact tests, and the actual rate of helmet ejection. Objectives: One of the main requirements of a protective helmet is to provide and maintain appropriate and adequate coverage to the head. A helmet that is poorly fitted or fastened may become displaced during normal use or even ejected during a crash.
Boxing headguard performance in punch machine tests
- Authors: McIntosh, Andrew , Patton, Declan
- Date: 2015
- Type: Text , Journal article
- Relation: British Journal of Sports Medicine Vol. 49, no. 17 (2015), p. 1108-1112
- Full Text: false
- Reviewed:
- Description: Background: The paper presents a novel laboratory method for assessing boxing headguard impact performance. The method is applied to examine the effects of headguards on head impact dynamics and injury risk. Methods: A linear impactor was developed, and a range of impacts was delivered to an instrumented Hybrid III head and neck system both with and without an AIBA (Association Internationale de Boxe Amateur)- approved headguard. Impacts at selected speeds between 4.1 and 8.3 m/s were undertaken. The impactor mass was approximately 4 kg and an interface comprising a semirigid 'fist' with a glove was used. Results: The peak contact forces were in the range 1.9-5.9 kN. Differences in head impact responses between the Top Ten AIBA-approved headguard and bare headform in the lateral and forehead tests were large and/or significant. In the 8.3 m/s fist-glove impacts, the mean peak resultant headform accelerations for bare headform tests was approximately 130 g compared with approximately 85 g in the forehead impacts. In the 6.85 m/s bare headform impacts, mean peak resultant angular head accelerations were in the range of 5200-5600 rad/s
Mild traumatic brain injury among a cohort of rugby union players: predictors of time to injury
- Authors: Hollis, Stephanie , Stevenson, Mark , McIntosh, Andrew , Li, Ling , Heritier, Stephane , Shores, E Arthur , Collins, Michael , Finch, Caroline
- Date: 2011
- Type: Text , Journal article
- Relation: British Journal of Sports Medicine Vol. 45, no. 12 (2011), p. 997-999
- Full Text: false
- Reviewed:
- Description: This study reports the time to sustain a mild traumatic brain injury (mTBI) among a cohort of community rugby union players. Demographic and player characteristics were collected and players followed up for between one and three playing seasons. 7% of the cohort sustained an mTBI within 10 h of game time, increasing twofold to 14% within 20 h. The mean time to first mTBI was 8 h with an SD of 6.2 (median 6.8 h; IQR: 2.9–11.7 h). Players reporting a recent history of concussion were 20% more likely to sustain an mTBI after 20 h of game time compared with those with no recent history of concussion. Players were likely to sustain an mTBI in shorter time if they trained for <3 h/week (HR=1.48, p=0.03) or had a body mass index <27 (HR=1.77, p=0.007). The findings highlight modifiable characteristics to reduce the likelihood of shortened time to mTBI.