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Objective: To examine the likelihood of head acceleration events (HAEs) as a function of previously identified risk factors: match time, player status (starter or substitute) and pitch location in elite-level men's and women's rugby union matches., Methods: Instrumented mouthguard data were collected from 179 and 107 players in the men's and women's games and synchronised to video-coded match footage. Head peak resultant linear acceleration (PLA) and peak resultant angular acceleration were extracted from each HAE. Field location was determined for HAEs linked to a tackle, carry or ruck. HAE incidence was calculated per player hour across PLA recording thresholds with 95% CIs estimated. Propensity was calculated as the percentage of contact events that caused HAEs across PLA recording thresholds, with a 95% CI estimated. Significance was assessed by non-overlapping 95% CIs., Results: 29 099 and 6277 HAEs were collected from 1214 and 577 player-matches in the men's and women's games. No significant differences in match quarter HAE incidence or propensity were found. Substitutes had higher HAE incidence than starters at lower PLA recording thresholds for men but similar HAE propensity. HAEs were more likely to occur in field locations with high contact event occurrence., Conclusion: Strategies to reduce HAE incidence need not consider match time or status as a substitute or starter as HAE rates are similar throughout matches, without differences in propensity between starters and substitutes. HAE incidence is proportional to contact frequency, and strategies that reduce either frequency or propensity for contact to cause head contact may be explored., Competing Interests: GT and BJ have received research funding from Prevent Biometrics and World Rugby. KAS and MB have received research funding from World Rugby. LS, RT, ECF, DMS and JB are employed by or contracted as consultants to World Rugby. GT previously conducted consultancy work for World Rugby. KAS and SPTK are employed by the Rugby Football Union. SH receives funding for his PhD studies from the Rugby Football Union and Premiership Rugby. BJ is a consultant with Premiership Rugby and the Rugby Football League. MC is employed by Premiership Rugby and was previously employed by the Rugby Football Union. PO'H has previously been contracted by the Rugby Football Union and is employed by Marker Diagnostics UK, a company developing salivary biomarker testing for sport-related concussion., (Copyright © Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Objectives: To examine the propensity of tackle height and the number of tacklers that result in head acceleration events (HAEs) in elite-level male and female rugby tackles., Methods: Instrumented mouthguard data were collected from women (n=67) and men (n=72) elite-level rugby players from five elite and three international teams. Peak linear acceleration and peak angular acceleration were extracted from HAEs. Propensities for HAEs at a range of thresholds were calculated as the proportion of tackles/carries that resulted in an HAE exceeding a given magnitude for coded tackle height (low, medium, high) and number of tacklers. Propensity ratios with 95% CIs were calculated for tackle heights and number of tacklers., Results: High tackles had a 32.7 (95% CI=6.89 to 155.02) and 41.2 (95% CI=9.22 to 184.58) propensity ratio to cause ball carrier HAEs>30 g compared with medium tackles for men and women, respectively. Low tackles had a 2.6 (95% CI=1.91 to 3.42) and 5.3 (95% CI=3.28 to 8.53) propensity ratio to cause tackler HAEs>30 g compared with medium tackles for men and women, respectively. In men, multiple tacklers had a higher propensity ratio (6.1; 95% CI=3.71 to 9.93) than singular tacklers to cause ball carrier HAEs>30 g but a lower propensity ratio (0.4; 95% CI=0.29 to 0.56) to cause tackler HAEs>30 g. No significant differences were observed in female tacklers or carriers for singular or multiple tacklers., Conclusion: To limit HAE exposure, rule changes and coaching interventions that promote tacklers aiming for the torso (medium tackle) could be explored, along with changes to multiple tackler events in the male game., Competing Interests: GT has received research funding from World Rugby and Prevent Biometrics and has previously conducted consultancy work for World Rugby. LS, RT, ÉCF and DMS are employed by or contracted as consultants for World Rugby., (Copyright © Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Objectives: Tackles making contact above the sternum increase concussion and head injury assessment (HIA) risk in Rugby Union. The sport has introduced harsher sanctions to change tackler behaviours to reduce this risk. This increased high tackle sanction numbers, though it is unknown whether sanction severity is associated with injury risk., Methods: The sanction decision made by match officials for tackles resulting in 157 HIA1 removals, of which 91 were confirmed concussions, was evaluated. The propensity of sanction types, ranging from no foul play to red card, was compared after calculating concussion and HIA1 numbers per 1000 tackles of each sanction, using total tackle number of each sanction type from one season of two elite professional competitions., Results: HIA1 removal and concussion risk increased as sanction severity increased. Red-carded tackles were 271.5 (95% CI 143.8 to 512.6) times more likely to result in concussions than legal tackles. Tacklers and ball carriers were more likely to experience concussions from sanctioned high tackles, with tackler risk 28.5 (95% CI 13.5 to 59.9) times higher for sanctioned high tackles compared with legal tackles, and ball carrier risk elevated 133.7-fold (95% CI 65.5 to 272.8) after sanctioned high tackles., Conclusion: Sanctioned high tackles significantly increase concussion and HIA1 risk to both tacklers and ball carriers. Current decision-making frameworks that guide sanction decisions do identify tackle behaviours that elevate clinical risk. Both tacklers and ball carriers would be less likely to experience concussions and head injuries if the frequency of illegal high tackles is decreased., Competing Interests: Competing interests: RT is employed in a consulting role with World Rugby, the governing body for the sport of Rugby Union globally. JB receives research funding from and manages the global concussion monitoring system for WR. SH has received research funding from World Rugby for other research studies on the sport. BH is employed as a video analyst with World Rugby. ECF is the Chief Medical Officer of World Rugby., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Objectives: Assess the validity and feasibility of current instrumented mouthguards (iMGs) and associated systems., Methods: Phase I; four iMG systems (Biocore-Football Research Inc (FRI), HitIQ, ORB, Prevent) were compared against dummy headform laboratory criterion standards (25, 50, 75, 100 g ). Phase II; four iMG systems were evaluated for on-field validity of iMG-triggered events against video-verification to determine true-positives, false-positives and false-negatives (20±9 player matches per iMG). Phase III; four iMG systems were evaluated by 18 rugby players, for perceptions of fit , comfort and function . Phase IV; three iMG systems (Biocore-FRI, HitIQ, Prevent) were evaluated for practical feasibility (System Usability Scale (SUS)) by four practitioners., Results: Phase I; total concordance correlation coefficients were 0.986, 0.965, 0.525 and 0.984 for Biocore-FRI, HitIQ, ORB and Prevent. Phase II; different on-field kinematics were observed between iMGs. Positive predictive values were 0.98, 0.90, 0.53 and 0.94 for Biocore-FRI, HitIQ, ORB and Prevent. Sensitivity values were 0.51, 0.40, 0.71 and 0.75 for Biocore-FRI, HitIQ, ORB and Prevent. Phase III; player perceptions of fit , comfort and function were 77%, 6/10, 55% for Biocore-FRI, 88%, 8/10, 61% for HitIQ, 65%, 5/10, 43% for ORB and 85%, 8/10, 67% for Prevent. Phase IV; SUS (preparation-management) was 51.3-50.6/100, 71.3-78.8/100 and 83.8-80.0/100 for Biocore-FRI, HitIQ and Prevent., Conclusion: This study shows differences between current iMG systems exist. Sporting organisations can use these findings when evaluating which iMG system is most appropriate to monitor head acceleration events in athletes, supporting player welfare initiatives related to concussion and head acceleration exposure., Competing Interests: Competing interests: GT, JT and DW have received Prevent Biometrics iMGs free of charge for use with Leeds Rhinos RLFC for a research project. BJ, MAD, KT are employed by Leeds Rhinos in a consultancy capacity. GT, JT and ÉCF use Prevent Biometrics iMG for research projects funded by World Rugby. GT submitted a funded research proposal for a different study to Prevent Biometrics during the review process of this article, which was subsequently successful. ÉCF is employed by World Rugby. BJ, JT, DW, KT, CO, KAS, GP, SH, MAD, GT are involved in the Rugby Football League Tackle and Contact Kinematic Load & Exposure (TaCKLE) project. BJ and KT will be involved in the procurement of iMGs for the TaCKLE project. BJ, GP are employed in a consultancy capacity by the Rugby Football League. KAS is employed by the Rugby Football Union. MB and SR lead the Virginia Tech Helmet Lab. Leeds Rhinos, World Rugby and Virginia Tech are research partners of Prevent Biometrics., (© Author(s) (or their employer(s)) 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

Competing Interests: Competing interests: None declared.

Background: Psychological factors including self-reported readiness to return to sport (RTS) after anterior cruciate ligament reconstruction (ACLR) measured with the Anterior Cruciate Ligament Return to Sport After Injury (ACL-RSI) scale have been shown to correlate with RTS. Physical deficits have been shown to exist in the later stages after ACLR rehabilitation. No previous studies have investigated the relationship between self-reported readiness to RTS and objective physical measures of power and strength., Purpose: To investigate the relationship between ACL-RSI scores and measures of strength and power scores after ACLR., Study Design: Case control study; Level of evidence, 3., Methods: This study recruited 452 male athletes who had undergone primary ACLR. Each athlete completed the ACL-RSI questionnaire, isokinetic strength testing, and jump testing approximately 9 months after surgery., Results: ACL-RSI scores showed a trivial or weak correlation with strength and power measures at 9 months after surgery ( r = 0.06-0.16). Similar results were found for the relationship between ACL-RSI scores and limb symmetry index for strength and power measures ( r = 0.04-0.15). Comparing the strength and power measures of athletes with higher (≥90) ACL-RSI scores (n = 93) versus athletes with lower (≤75) ACL-RSI scores (n = 92) showed no significant differences except for isokinetic hamstring strength, but with a trivial effect size ( P = .040; effect size = 0.15)., Conclusion: Self-reported readiness to RTS as measured by the ACL-RSI had little or no relationship with athletes' strength and power measures, and there was no meaningful difference in strength and power between athletes with higher and lower ACL-RSI scores at 9 months after ACLR. The findings suggest that psychological recovery and physical recovery after ACLR are different constructs, and strategies to measure and address each construct separately may be necessary to ensure successful RTS after ACLR.

Background: Video review has become an important tool in professional sporting codes to help sideline identification and management of players with a potential concussion., Aim: To assess current practices related to video review of concussion in professional sports internationally, and compare protocols and diagnostic criteria used to identify and manage potential concussions., Methods: Current concussion management guidelines from professional national and international sporting codes were reviewed. Specific criteria and definitions of video signs associated with concussion were compared between codes. Rules and regulations adopted across the codes for processes around video review were also assessed., Results: Six sports with specific diagnostic criteria and definitions for signs of concussion identified on video review participated in this study (Australian football, American football, world rugby, cricket, rugby league and ice hockey). Video signs common to all sports include lying motionless/loss of responsiveness and motor incoordination . The video signs considered by the majority of sports as most predictive of a diagnosis of concussion include motor incoordination, impact seizure, tonic posturing and lying motionless. Regulatory requirements, sideline availability of video, medical expertise of video reviewers and use of spotters differ across sports and geographical boundaries. By and large, these differences reflect a pragmatic approach from each sport, with limited underlying research and development of the video review process in some instances., Conclusions: The use of video analysis in assisting medical staff with the diagnosis or identification of potential concussion is well established across different sports internationally. The diagnostic criteria used and the expertise of the video review personnel are not clearly established, and research efforts would benefit from a collaborative harmonisation across sporting codes., Competing Interests: Competing interests: GAD is an Honorary member of the AFL Concussion Working Group. MM is an Honorary member of the AFL Concussion Working Group. PB is Chief Medical Officer of NRL. PC is Head of Health, Safety & Laws, AFL. RJE is Co-Chair, NHL NHLPA Concussion Subcommittee and Chair of the MLS Concussion Committee. ECF is Member of World Rugby concussion working group. GWF is a member of the World Rugby Concussion Working Group. GG is Medical Director, Major League Baseball. PRH is AFL Medical Director. TH is State Medical Officer, Cricket Australia. NM is General Manager, Competitions and Operations, Football, NRL. WM is Medical Director, National Hockey League. JO is Chief Medical Officer, Cricket Australia. MR is Chief Medical Officer, World Rugby. AKS is Chief Medical Officer, NFL. GSS is Senior Adviser, NFL Department of Health and Safety. AV is Consultant for Mild Traumatic Brain Injury, Major League Baseball. PM is an Honorary member of the AFL Concussion Working Group. ICJME disclosure forms have been provided., (© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: The use of video to assist professional sporting bodies with the diagnosis of sport-related concussion (SRC) has been well established; however, there has been little consistency across sporting codes with regards to which video signs should be used, and the definitions of each of these signs., Aim: The aims of this study were to develop a consensus for the video signs considered to be most useful in the identification of a possible SRC and to develop a consensus definition for each of these video signs across the sporting codes., Methods: A brief questionnaire was used to assess which video signs were considered to be most useful in the identification of a possible concussion. Consensus was defined as >90% agreement by respondents. Existing definitions of these video signs from individual sports were collated, and individual components of the definitions were assessed and ranked. A modified Delphi approach was then used to create a consensus definition for each of the video signs., Results: Respondents representing seven sporting bodies (Australian Football League, Cricket Australia, Major League Baseball, NFL, NHL, National Rugby League, World Rugby) reached consensus on eight video signs of concussion. Thirteen representatives from the seven professional sports ranked the definition components. Consolidation and refinement of the video signs and their definitions resulted in consensus definitions for six video signs of possible concussion: lying motionless, motor incoordination, impact seizure, tonic posturing, no protective action-floppy and blank/vacant look ., Conclusions: These video signs and definitions have reached international consensus, are indicated for use by professional sporting bodies and will form the basis for further collaborative research., Competing Interests: Competing interests: GAD is an Honorary member of the Australian Football League (AFL) Concussion Working Group. MM is an Honorary member of the AFL Concussion Working Group. PB is Chief Medical Officer of National Rugby League (NRL). PC is Head of Health, Safety and Laws, AFL. RJE is Co-Chair, National Hockey League (NHL)/NHL Players Association Concussion Subcommittee and Chair of the MLS Concussion Committee. ECF is Member of World Rugby concussion working group. GWF is Member of World Rugby concussion working group. GG is Medical Director, Major League Baseball. PH is AFL Medical Director. TH is State Medical Officer, Cricket Australia. NM is General Manager, Competitions and Operations, Football, NRL. WM is NHL Medical Director. JO is Chief Medical Officer, Cricket Australia. MR is Chief Medical Officer, World Rugby. AKS is Chief Medical Officer, National Football League (NFL). GSS is Senior Advisor, NFL Department of Health and Safety. AV is a consultant for Mild Traumatic Brain Injury, Major League Baseball. PM is an Honorary member of the AFL Concussion Working Group. ICJME disclosure forms have been provided., (© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

After anterior cruciate ligament reconstruction (ACLR), there is a higher re-injury rate to the contralateral limb in athletes who undergo surgery using a bone-patellar-tendon-bone (BPTB) autograft than using a semitendinosus and gracilis hamstring tendon (HT) autograft. This may be influenced by differing lower-limb loading asymmetries present when athletes of each graft type return to play (RTP). The aim of this study was to compare bilateral countermovement jump (CMJ) phase-specific impulse asymmetries between athletes with BPTB and HT autografts 9 months post-ACLR, and to identify the relationship between impulse and isokinetic strength asymmetries. Male field sport athletes with a BPTB (n = 22) or HT (n = 22) autograft were tested approximately 9 months post-ACLR. An uninjured control group (n = 22) was also tested on a single occasion. Phase-specific bilateral absolute impulse asymmetries were calculated during the CMJ and compared between groups using Kruskal-Wallis and post-hoc testing. A linear regression model was used to assess the relationship between impulse asymmetries and isokinetic concentric knee extensor strength asymmetries. BPTB athletes demonstrated greater impulse asymmetries than HT athletes during the eccentric (P = 0.01) and concentric (P = 0.008) phases of the jump. Isokinetic strength asymmetry was a significant predictor of CMJ concentric impulse asymmetry in both BPTB (r 2  = 0.39) and HT athletes (r 2  = 0.18) but not eccentric impulse asymmetry in any group. The greater loading asymmetries demonstrated by BPTB than HT athletes 9 months after ACLR may contribute to the differing incidence rates of contralateral ACL injury. The findings suggest that graft-specific loading asymmetries should be targeted during rehabilitation prior to RTP., (© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

The 2017 Berlin Concussion in Sport Group Consensus Statement provides a global summary of best practice in concussion prevention, diagnosis and management, underpinned by systematic reviews and expert consensus. Due to their different settings and rules, individual sports need to adapt concussion guidelines according to their specific regulatory environment. At the same time, consistent application of the Berlin Consensus Statement's themes across sporting codes is likely to facilitate superior and uniform diagnosis and management, improve concussion education and highlight collaborative research opportunities. This document summarises the approaches discussed by medical representatives from the governing bodies of 10 different contact and collision sports in Dublin, Ireland in July 2017. Those sports are: American football, Australian football, basketball, cricket, equestrian sports, football/soccer, ice hockey, rugby league, rugby union and skiing. This document had been endorsed by 11 sport governing bodies/national federations at the time of being published., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Context: Chronic athletic groin pain (AGP) is common in field sports and has been associated with abnormal movement control and loading of the hip and pelvis during play. A single-leg squat (SLS) is commonly used by clinicians to assess movement control, but whether it can provide insight into control during more dynamic sporting movements in AGP patients is unclear., Objective: To determine the relationships between biomechanical measures in an SLS and the same measures in a single-leg drop landing, single-leg hurdle hop, and a cutting maneuver in AGP patients., Design: Cross-sectional study., Setting: Biomechanics laboratory., Patients: 40 recreational field-sports players diagnosed with AGP., Intervention: A biomechanical analysis of each individual's SLS, drop landing, hurdle hop, and cut was undertaken., Main Outcome Measures: Hip, knee, and pelvis angular displacement and hip and knee peak moments. Pearson product-moment correlations were used to examine relationships between SLS measures and equivalent measures in the other movements., Results: There were no significant correlations between any hip or pelvis measure in the SLS with the same measures in the drop landing, hurdle hop, or cut (r = .03-.43, P > .05). Knee frontal- and transverse-plane angular displacement were related in the SLS and drop landing only, while knee moments were related in the SLS, drop-landing, and hurdle hop (r = .50-.67, P < .05)., Conclusion: For AGP patients, an SLS did not provide meaningful insight into hip and pelvis control or loading during sporting movements that are associated with injury development. The usefulness of an SLS test in the assessment of movement control and loading in AGP patients is thus limited. The SLS provided moderate insight into knee control while landing and therefore may be of use in the examination of knee-injury risk.

Background: Athletic groin pain remains a common field-based team sports time-loss injury. There are few reports of non-surgically managed cohorts with athletic groin pain., Aim: To describe clinical presentation/examination, MRI findings and patient-reported outcome (PRO) scores for an athletic groin pain cohort., Methods: All patients had a history including demographics, injury duration, sport played and standardised clinical examination. All patients underwent MRI and PRO score to assess recovery. A clinical diagnosis of the injured anatomical structure was made based on these findings. Statistical assessment of the reliability of accepted standard investigations undertaken in making an anatomical diagnosis was performed., Result: 382 consecutive athletic groin pain patients, all male, enrolled. Median time in pain at presentation was (IQR) 36 (16-75) weeks. Most (91%) played field-based ball-sports. Injury to the pubic aponeurosis (PA) 240 (62.8%) was the most common diagnosis. This was followed by injuries to the hip in 81 (21.2%) and adductors in 56 (14.7%) cases. The adductor squeeze test (90° hip flexion) was sensitive (85.4%) but not specific for the pubic aponeurosis and adductor pathology (negative likelihood ratio 1.95). Analysed in series, positive MRI findings and tenderness of the pubic aponeurosis had a 92.8% post-test probability., Conclusions: In this largest cohort of patients with athletic groin pain combining clinical and MRI diagnostics there was a 63% prevalence of PA injury. The adductor squeeze test was sensitive for athletic groin pain, but not specific individual pathologies. MRI improved diagnostic post-test probability. No hernia or incipient hernia was diagnosed., Clinical Trial Registration Number: NCT02437942., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Cutting ability is an important aspect of many team sports, however, the biomechanical determinants of cutting performance are not well understood. This study aimed to address this issue by identifying the kinetic and kinematic factors correlated with the time to complete a cutting maneuver. In addition, an analysis of the test-retest reliability of all biomechanical measures was performed. Fifteen (n = 15) elite multidirectional sports players (Gaelic hurling) were recruited, and a 3-dimensional motion capture analysis of a 75° cut was undertaken. The factors associated with cutting time were determined using bivariate Pearson's correlations. Intraclass correlation coefficients (ICCs) were used to examine the test-retest reliability of biomechanical measures. Five biomechanical factors were associated with cutting time (2.28 ± 0.11 seconds): peak ankle power (r = 0.77), peak ankle plantar flexor moment (r = 0.65), range of pelvis lateral tilt (r = -0.54), maximum thorax lateral rotation angle (r = 0.51), and total ground contact time (r = -0.48). Intraclass correlation coefficient scores for these 5 factors, and indeed for the majority of the other biomechanical measures, ranged from good to excellent (ICC >0.60). Explosive force production about the ankle, pelvic control during single-limb support, and torso rotation toward the desired direction of travel were all key factors associated with cutting time. These findings should assist in the development of more effective training programs aimed at improving similar cutting performances. In addition, test-retest reliability scores were generally strong, therefore, motion capture techniques seem well placed to further investigate the determinants of cutting ability.