Three-dimensional mechanics of the rugby tackle, does the ball carrier alter their movement into contact in response to the tackler’s position?

Author(s):  
Suzi Edwards ◽  
Timana Tahu ◽  
Matthew Buchanan ◽  
Ross Tucker ◽  
Gordon Fuller ◽  
...  

In rugby league and rugby union, the ball carrier is vulnerable to injury during a tackle. The height of the tackle has been associated with injury risk. The extent to which a ball carrier may alter their approach entering a tackle in response the tackler’s body height is unknown. This exploratory study aimed to identify if, when and how, the ball carrier modified their motion when being tackled in response to tackling instructions given to the tackler. Three-dimensional analysis was completed on 15 adult male rugby union/league players performing a front-on, one-on-one tackle at differing tackle heights. Repeated measure factorial analyses of variance were used to test for differences (P < 0.05). The ball carrier used two movement strategies: (1) increasing their stability by flexing their trunk, knee, and hips more when entering mid/high torso tackles; (2) offloading the ball or performing an evasive movement strategy by positioning themselves in a more upright body position when being tackled at a lower torso tackle height. This preliminary evidence suggests it may be beneficial for a coach to provide different instructions to the ball carrier to modify their movement strategies when being tackled in response to the height of the tackler to improve their performance and decrease their potential injury risk.

2021 ◽  
Author(s):  
Andrew J Gardner ◽  
Grant Iverson ◽  
Suzi Edwards ◽  
Ross Tucker

Abstract Background The tackle is the in-game activity carrying the greatest risk for concussion in Rugby. A recent evaluation of tackle characteristics in Rugby Union precipitated a rule modification to reduce head impact risk during tackles. This study aims to replicate the work conducted in Rugby Union by examining the association between tackle characteristics and head injury events in professional Rugby League. Methods We reviewed and coded 446 tackles resulting in a head injury assessment (HIA) and 5,694 tackles that did not result in a head injury from two National Rugby League (NRL) seasons. Tackle height, body position of players, and contact area on an opponent’s body were evaluated, with the propensity of each situation to cause an HIA calculated as HIAs per 1000 events. Results The propensity for tacklers to sustain a head injury was 0.99 HIAs per 1000 tackles, 1.74-fold greater than for the ball carrier (0.57 HIAs per 1,000 tackles). There was a 3.2-fold higher risk for an HIA when the tackler was upright compared to bent-at-the-waist. The greatest risk of a tackler HIA occurred when head contact was very low (knee, boot) or high (head and elbow). HIAs were most common following head-to-head impacts. The lowest propensity for tackler HIA was found when the tackler’s head was in proximity with the ball carrier’s torso. Conclusions The result of this study replicated the findings in professional rugby union. This has implications for the injury prevention initiatives implemented to reduce HIA risk because the majority of injuries are sustained by the player initiating the action.


Author(s):  
Suzi Edwards ◽  
Timana Tahu ◽  
Matthew Buchanan ◽  
Ross Tucker ◽  
Gordon Fuller ◽  
...  

The tackle is the in-game activity with the greatest risk for injury in collision sports. Qualitative match analysis has associated injury risk with tackle technique (e.g. tackle height, head position before contact). This exploratory study used gold-standard three-dimensional (3D) motion capture to investigate whether prior instructions to a tackler to execute different torso tackle types altered their tackle technique. Fifteen amateur-level rugby code players performed four sets of 10 tackle trials after instructions from an expert coach: two Australian National Rugby League (NRL) coaching manual instructions on upper and lower torso tackle height (UpperNRL, LowerNRL); and two novel variants that altered the tackler’s contact with the ball carrier’s upper torso ( UpperPop) via a vertical ‘pop action’, or mid-torso ( MidTorso) via increasing the contact height to the mid-torso. 3 D motion capture confirmed a favourable ‘head up and forward’ gaze focus on ball carrier before contact and a ‘straight back’ posture was more evident in UpperPop instruction than other instructions, with the least flexion for the head, trunk, trunk-pelvis, thoracolumbar and lumbopelvic (p < 0.01). MidTorso also attained a more optimal ‘head up and forward’ and a ‘straight back’ posture than a LowerNRL (p < 0.001). ‘Leg drive on contact’ revealed ankle, hip (p < 0.01) and thigh angles (p < 0.05) differences, likely to reflect the UpperPop ‘pop action’ instruction than other instructions. For coaches, this study demonstrated that amateur-level rugby-code players could follow instruction from an expert coach to execute tackling techniques within a session. Inclusion of tackle specific coaching instruction training program may be a viable injury reduction strategy.


2017 ◽  
Vol 51 (11) ◽  
pp. A70.2-A70 ◽  
Author(s):  
Ross Tucker ◽  
Ben Hester ◽  
Matthew Cross ◽  
Simon Kemp ◽  
Martin Raftery

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Andrew J. Gardner ◽  
Grant L. Iverson ◽  
Suzi Edwards ◽  
Ross Tucker

Abstract Background The tackle is the in-game activity carrying the greatest risk for concussion in rugby. A recent evaluation of tackle characteristics in rugby union precipitated a rule modification to reduce head impact risk during tackles. This study aims to replicate the work conducted in rugby union by examining the association between tackle characteristics and head injury events in professional rugby league. Methods There were 446 tackles resulting in a head injury assessment (HIA) and 5,694 tackles that did not result in a head injury from two National Rugby League (NRL) seasons that were reviewed and coded. Tackle height, body position of players, and contact area on an opponent’s body were evaluated, with the propensity of each situation to cause an HIA calculated as HIAs per 1000 events. Results The propensity for tacklers to sustain a head injury was 0.99 HIAs per 1000 tackles, 1.74-fold greater than for the ball carrier (0.57 HIAs per 1000 tackles). There was a 3.2-fold higher risk for an HIA when the tackler was upright compared to bent-at-the-waist. The greatest risk of a tackler HIA occurred when head contact was very low (knee, boot) or high (head and elbow). HIAs were most common following head-to-head impacts. The lowest propensity for tackler HIA was found when the tackler’s head was in proximity with the ball carrier’s torso. Conclusions The result of this study replicated the findings in professional rugby union. This has implications for the injury prevention initiatives implemented to reduce HIA risk because the majority of injuries are sustained by the tackler.


Author(s):  
Craig Barden ◽  
Kenneth L. Quarrie ◽  
Carly McKay ◽  
Keith A Stokes

AbstractInjury surveillance systems seek to describe injury risk for a given sport, in order to inform preventative strategies. This often leads to comparisons between studies, although these inferences may be inappropriate, considering the range of methods adopted. This study aimed to describe the injury epidemiology of seven youth sports, enabling valid comparisons of injury risk. Consistent methods were employed across seven sports [male American football, basketball, soccer, rugby league, rugby union; female soccer and rugby union] at a high school in England. A 24-hour time-loss injury definition was adopted. Descriptive statistics and injury incidence (/1000 match-hours) are reported. In total, 322 injuries were sustained by 240 athletes (mean age=17.7±1.0) in 10 273 player-match hours. American football had a significantly greater injury incidence (86/1000 h; 95% CI 61–120) than all sports except female rugby union (54/1000 h; 95% CI 37–76). Concussion was the most common injury (incidence range 0.0–26.7/1000 h), while 59% of injuries occurred via player contact. This study employed standardized data collection methods, allowing valid and reliable comparisons of injury risk between youth sports. This is the first known study to provide epidemiological data for female rugby union, male basketball and American football in an English youth population, enabling the development of preventative strategies.


2018 ◽  
Vol 53 (16) ◽  
pp. 1026-1033 ◽  
Author(s):  
Doug King ◽  
Patria A Hume ◽  
Natalie Hardaker ◽  
Cloe Cummins ◽  
Conor Gissane ◽  
...  

ObjectivesTo provide epidemiological data and related costs for sport-related injuries of five sporting codes (cricket, netball, rugby league, rugby union and football) in New Zealand for moderate-to-serious and serious injury claims.MethodsA retrospective analytical review using detailed descriptive epidemiological data obtained from the Accident Compensation Corporation (ACC) for 2012–2016.ResultsOver the 5 years of study data, rugby union recorded the most moderate-to-serious injury entitlement claims (25 226) and costs (New Zealand dollars (NZD$)267 359 440 (£139 084 749)) resulting in the highest mean cost (NZD$10 484 (£5454)) per moderate-to-serious injury entitlement claim. Rugby union recorded more serious injury entitlement claims (n=454) than cricket (t(4)=−66.6; P<0.0001); netball (t(4)=−45.1; P<0.0001); rugby league (t(4)=−61.4; P<0.0001) and football (t(4)=66.6; P<0.0001) for 2012–2016. There was a twofold increase in the number of female moderate-to-serious injury entitlement claims for football (RR 2.6 (95%CI 2.2 to 2.9); P<0.0001) compared with cricket, and a threefold increase when compared with rugby union (risk ratio (RR) 3.1 (95%CI 2.9 to 3.3); P<0.0001). Moderate-to-serious concussion claims increased between 2012 and 2016 for netball (RR 3.7 (95%CI 1.9 to 7.1); P<0.0001), rugby union (RR 2.0 (95% CI 1.6 to 2.4); P<0.0001) and football (RR 2.3 (95%CI 1.6 to 3.2); P<0.0001). Nearly a quarter of moderate-to-serious entitlement claims (23%) and costs (24%) were to participants aged 35 years or older.ConclusionsRugby union and rugby league have the highest total number and costs associated with injury. Accurate sport exposure data are needed to enable injury risk calculations.


2021 ◽  
Vol 7 (2) ◽  
pp. e001018
Author(s):  
Craig Barden ◽  
Keith A Stokes ◽  
Carly D McKay

ObjectivesThe implementation of the Activate injury prevention exercise programme has not been assessed in an applied context. This study aimed to (1) describe the knowledge and perceptions of school rugby coaches and players towards injury risk, prevention and Activate and (2) evaluate Activate implementation in schoolboy rugby using the reach, effectiveness, adoption, implementation and maintenance framework.MethodsBespoke electronic surveys were administered to coaches (including support staff) and players at participating English schools (2018–2020). Most questions and statements were answered using a 7-point Likert scale. At baseline, participants detailed their Activate awareness and perceptions of injury risk and prevention in schoolboy rugby. At postseason, participants reported Activate use throughout the study and their perceptions towards the programme.ResultsAt baseline, significant differences existed between coaches (n=106) and players (n=571) in Activate awareness (75% and 13% respectively; χ2=173.5, p<0.001). Coaches perceived rugby had a significantly greater injury risk than players, while holding more positive perceptions towards injury prevention. At postseason, coaches reported greater Activate adoption compared with players (76% and 18% respectively; χ2=41.8, p<0.001); 45% of players were unaware if they used the programme. Median session adherence was twice weekly, with a median duration of 10–15 min. This suggests Activate was not implemented as intended, with recommendations of three 20 min sessions per week. Both groups identified common barriers to implementation, such as lack of time and inclusion of a ball.ConclusionCoaches are instrumental in the decision to implement Activate. Targeting behavioural change in these individuals is likely to have the greatest impact on intervention uptake.


Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 580
Author(s):  
Anna Lena Emonds ◽  
Katja Mombaur

As a whole, human sprinting seems to be a completely periodic and symmetrical motion. This view is changed when a person runs with a running-specific prosthesis after a unilateral amputation. The aim of our study is to investigate differences and similarities between unilateral below-knee amputee and non-amputee sprinters—especially with regard to whether asymmetry is a distracting factor for sprint performance. We established three-dimensional rigid multibody models of one unilateral transtibial amputee athlete and for reference purposes of three non-amputee athletes. They consist of 16 bodies (head, ipper, middle and lower trunk, upper and lower arms, hands, thighs, shanks and feet/running specific prosthesis) with 30 or 31 degrees of freedom (DOFs) for the amputee and the non-amputee athletes, respectively. Six DOFs are associated with the floating base, the remaining ones are rotational DOFs. The internal joints are equipped with torque actuators except for the prosthetic ankle joint. To model the spring-like properties of the prosthesis, the actuator is replaced by a linear spring-damper system. We consider a pair of steps which is modeled as a multiphase problem with each step consisting of a flight, touchdown and single-leg contact phase. Each phase is described by its own set of differential equations. By combining motion capture recordings with a least squares optimal control problem formulation including constraints, we reconstructed the dynamics of one sprinting trial for each athlete. The results show that even the non-amputee athletes showed less symmetrical sprinting than expected when examined on an individual level. Nevertheless, the asymmetry is much more pronounced in the amputee athlete. The amputee athlete applies larger torques in the arm and trunk joints to compensate the asymmetry and experiences a destabilizing influence of the trunk movement. Hence, the inter-limb asymmetry of the amputee has a significant effect on the control of the sprint movement and the maintenance of an upright body position.


2015 ◽  
Vol 49 (8) ◽  
pp. 506-510 ◽  
Author(s):  
Graham Kirkwood ◽  
Nikesh Parekh ◽  
Richard Ofori-Asenso ◽  
Allyson M Pollock

2020 ◽  
Vol 17 (1) ◽  
pp. 67-75
Author(s):  
John Fry ◽  
Oliver Smart ◽  
Jean-Philippe Serbera ◽  
Bernhard Klar

Abstract Amid much recent interest we discuss a Variance Gamma model for Rugby Union matches (applications to other sports are possible). Our model emerges as a special case of the recently introduced Gamma Difference distribution though there is a rich history of applied work using the Variance Gamma distribution – particularly in finance. Restricting to this special case adds analytical tractability and computational ease. Our three-dimensional model extends classical two-dimensional Poisson models for soccer. Analytical results are obtained for match outcomes, total score and the awarding of bonus points. Model calibration is demonstrated using historical results, bookmakers’ data and tournament simulations.


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