scholarly journals Head Accelerations during a 1-on-1 Rugby Tackling Drill Performed by Experienced Rugby Union Players

2021 ◽  
Vol 11 (11) ◽  
pp. 1497
Author(s):  
Tahere Reha ◽  
Colm McNabb ◽  
Kevin Netto ◽  
Paul Davey ◽  
Andrew P. Lavender
Keyword(s):  
Head Injuries ◽  
Three Dimensional ◽  
Rugby Union ◽  
Head Movements ◽  
Mitigation Strategies ◽  
Brain Health ◽  
Head Impacts ◽  
Experienced Male ◽  
Analysis Laboratory ◽  
Males And Females

Rugby Union is a popular sport played by males and females worldwide, from junior to elite levels. The highly physical skill of tackling occurs every few seconds throughout a match and various injuries associated with tackling are relatively common. Of particular interest are head injuries that result in a concussion. Recently, repeated non-injurious head impacts in sport have attracted the attention of researchers interested in brain health. Therefore, this study assessed head movement during repeated rugby tackle drills among experienced Rugby Union players. Experienced male and female participants performed 15 1-on-1 tackles in a motion analysis laboratory to measure the head movements of the ball carrier and tackler during each tackle, using three-dimensional motion capture. The average peak acceleration of the head for ball carriers was 28.9 ± 24.08 g and 36.67 ± 28.91 g for the tacklers. This study found that the type of head impacts common while performing a tackle in Rugby Union are similar to those experienced by soccer players during heading, which has been found to alter brain function that lasts hours after the event. This has important implications for player health and suggests that mitigation strategies should be considered for Rugby Union.

scholarly journals Concussion in Rugby Union and the Role of Biomechanics

Res Medica ◽  
2017 ◽  
Vol 24 (1) ◽  
pp. 87-95
Author(s):  
Gregory J Tierney ◽  
Ciaran K Simms
Keyword(s):  
Medical Staff ◽  
Brain Injuries ◽  
Sports Injuries ◽  
Head Injuries ◽  
Rugby Union ◽  
American Football ◽  
Head Impacts ◽  
Major Disadvantage ◽  
Protection Strategies ◽  
Biomechanical Forces

Due to the physical and high-impact nature of rugby, head impacts can occur within the game which can result in concussion injuries as well as other moderate-to-severe head injuries 1. Concussion has been defined as “a complex pathophysiological process affecting the brain, induced by traumatic biomechanical forces”1 and was found to be one of the more common brain injuries throughout the world.2 This is particularly true in sport; it has been estimated that over half of all concussions are sports related.3 A systematic review of the incidence of concussion in contact sports found that rugby union has a higher incidence rate compared with other sports such as American football and soccer.4 Unlike other sports injuries, detecting a concussion is difficult as the neuropathological changes cannot be recognized on standard neuroimaging technology.5,6 \Therefore, if a player is suspected of having a concussion, they are removed from play for a Head Injury Assessment (HIA). The HIA is a standardized tool for the medical assessment of concussion injuries in rugby and aims to improve detection and patient education.7 The HIA assesses a range of degenerative concussive symptoms including memory, cognitive ability, balance and player discomfort. This concussion diagnosis protocol therefore relies heavily on side-line medical staff to identify if a player is exhibiting concussive symptoms. A major disadvantage to this is that concussion has a variable natural history, with transient, fluctuating, delayed and evolving signs or symptoms.8) This means that symptoms can take up to 48 hours to become apparent.8 It has therefore been acknowledged that the content of the HIA will be modified as the research around concussion diagnosis evolves.8 The reliance on side-line medical staff to accurately identify concussive symptoms means that there is a possibility a concussed player may remain on the field; this is one problem that biomechanical research into concussion is trying to overcome.  This study will give an overview of concussion in rugby union with a focus on incidence, severity and protection strategies. It will discuss current biomechanical research and further biomechanical research required in the area of concussion injuries in rugby union.

scholarly journals Padded Headgear does not Reduce the Incidence of Match Concussions in Professional Men’s Rugby Union: A Case-control Study of 417 Cases

2021 ◽  
Author(s):  
Keith A. Stokes ◽  
Matthew Cross ◽  
Sean Williams ◽  
Carly McKay ◽  
Brent E. Hagel ◽  
...  
Keyword(s):  
Odds Ratio ◽  
Head Injuries ◽  
Median Number ◽  
Case Control ◽  
Rugby Union ◽  
Return To Play ◽  
Injury Incidence ◽  
Video Footage ◽  
Four Seasons ◽  
Nested Case Control

AbstractConcussion is the most common match injury in rugby union. Some players wear padded headgear, but whether this protects against concussion is unclear. In professional male rugby union players, we examined: (i) the association between the use of headgear and match concussion injury incidence, and (ii) whether wearing headgear influenced time to return to play following concussion. Using a nested case-control within a cohort study, four seasons (2013–2017) of injury data from 1117 players at the highest level of rugby union in England were included. Cases were physician-diagnosed concussion injuries. Controls were other contact injuries (excluding all head injuries). We determined headgear use by viewing video footage. Sixteen percent of cases and controls wore headgear. Headgear use had no significant effect on concussion injury incidence (adjusted odds ratio=1.05, 95% CI: 0.71–1.56). Median number of days absent for concussion whilst wearing headgear was 8 days, compared with 7 days without headgear. Having sustained a concussion in the current or previous season increased the odds of concussion more than four-fold (odds ratio=4.55, 95% CI: 3.77–5.49). Wearing headgear was not associated with lower odds of concussions or a reduced number of days' absence following a concussion.

scholarly journals A Variance Gamma model for Rugby Union matches

2020 ◽  
Vol 17 (1) ◽  
pp. 67-75
Author(s):  
John Fry ◽  
Oliver Smart ◽  
Jean-Philippe Serbera ◽  
Bernhard Klar
Keyword(s):  
Three Dimensional ◽  
Rugby Union ◽  
Three Dimensional Model ◽  
Gamma Model ◽  
Variance Gamma ◽  
Poisson Models ◽  
History Of ◽  
Bonus Points ◽  
Variance Gamma Model ◽  
Special Case

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.

Age-Dependent Three-Dimensional Evaluation of the Spheno-Occipital Synchondrosis Using Computed Tomography

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Arezoo Jahanbin ◽  
Shirin Dokht Shirazi ◽  
Elaheh Kamyabnezhad ◽  
Neda Eslami ◽  
Seyed Hosein Hoseini Zarch
Keyword(s):  
Developmental Stage ◽  
Three Dimensional ◽  
Cross Sectional ◽  
Old Patients ◽  
Significant Difference ◽  
Growth Center ◽  
Different Populations ◽  
Males And Females ◽  
Ossification Process ◽  
Age And Sex

Background: The spheno‐occipital synchondrosis (SOS) is an important growth center which plays an important role in cranial base development and can define the final relation of SOS with the upper and lower jaws. The morphology and fusion degree of SOS varies in different ages among different populations. Objectives: Thus, the aim of this study was to evaluate the age and sex dependence of ossification of the spheno-occipital synchondrosis in the Iranian population using CBCT. Methods: This cross-sectional retrospective study was performed on 517 CBCT images of 6- to 18-year-old patients in Mashhad, Iran. Patients with obvious pathology or fractures were excluded from the study. The SOS ossification was classified into four stages from 0 to 3. Two independent observers scored the images. The ossification stage of the SOS was classified according to the age and sex of the patients. Kruskal-Wallis and Kendall’s tau-b used for statistical analysis. Results: In this study, 517 samples of 260 females (50.3%) and 257 males (49.7%) with a mean age of 12.03 ± 3.74 years were examined. A significant difference did not exist between males and females regarding their stage of SOS ossification, although males were younger at the SOS transitional stages of 0 to 1, and 1 to 2 compared to females. Also, the SOS starts the ossification process at the age of 11 in females and 10.8 in males. Conclusions: The present study showed in the mean age of 16.81 ± 1.12 years, most subjects were in developmental stage 3. Due to the fact that in developmental stage 3 SOS closes, there were no passive maxillary growth after this time. In none of the SOS stages, females and males differed significantly in mean age (P > 0.05). The age of the onset of SOS closure in females was 11 years and in males it was about 10.8 years.

scholarly journals A Qualitative Study of Youth Football Coaches’ Perception of Concussion Safety in American Youth Football and Their Experiences With Implementing Tackling Interventions

2020 ◽  
pp. 1-9
Author(s):  
Kelly Sarmiento ◽  
Dana Waltzman ◽  
Kelley Borradaile ◽  
Andrew Hurwitz ◽  
Kara Conroy ◽  
...  
Keyword(s):  
Head Injuries ◽  
Young Age ◽  
Long Term Effects ◽  
Head Impacts ◽  
Football Coaches ◽  
Youth Athletes ◽  
Risks And Benefits ◽  
Youth Football ◽  
Tackle Football

Due in part to concern about the potential long-term effects of concussion and repetitive head injuries in football, some programs have implemented tackling interventions. This paper explores youth football coaches’ perception of football safety and their experiences implementing these interventions aimed at athlete safety. Using a qualitative approach, coaches were interviewed by means of a semi-structured protocol that covered: (a) demographics; (b) background and experiences with contact sports; (c) perceived concussion risks and benefits of youth football; (d) experiences with tackling technique; (e) experiences with mouth guard sensors; and (f) personal sources of training related to football safety. Most coaches felt that learning tackling at a young age helped prepare them for their playing later in life and believed that youth should begin playing tackle football at a young age. Coaches were mixed regarding their concerns about the risk for concussion and subconcussive head impacts. Still, most were receptive to changes in rules and policies aimed at making football safer. Findings from this study demonstrate that youth football coaches are important stakeholders to consider when implementing changes to youth football. Understanding coach perceptions and experiences may inform future efforts aimed to educate coaches on rules and policies to make the game safer for youth athletes.

scholarly journals The Reliability of Transcranial Magnetic Stimulation-Derived Corticomotor Inhibition as a Brain Health Evaluation Tool in Soccer Players

2022 ◽  
Vol 8 (1) ◽  
Author(s):  
Thomas G. Di Virgilio ◽  
Magdalena Ietswaart ◽  
Ragul Selvamoorthy ◽  
Angus M. Hunter
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Rectus Femoris ◽  
Corticospinal Excitability ◽  
Soccer Players ◽  
Group Differences ◽  
Evaluation Tool ◽  
Brain Health ◽  
Actual Measurement ◽  
Head Impacts

Abstract Background The suitability of corticomotor inhibition and corticospinal excitability to measure brain health outcomes and recovery of sport-related head impact (concussion and subconcussion) depends on good inter-day reliability, which is evaluated in this study. Transcranial magnetic stimulation (TMS) reliability in soccer players is assessed by comparing soccer players, for whom reliability on this measure may be reduced due to exposure to head impacts, to generally active individuals not engaged in contact sport. Methods TMS-derived corticomotor inhibition and corticospinal excitability were recorded from the rectus femoris muscle during two testing sessions, spaced 1–2 weeks apart in 19 soccer players (SOC—age 22 ± 3 years) and 20 generally active (CON—age 24 ± 4 years) healthy volunteers. Inter-day reliability between the two time points was quantified by using intra-class correlation coefficients (ICC). Intra-group reliability and group differences on actual measurement values were also explored. Results Good inter-day reliability was evident for corticomotor inhibition (ICCSOC = 0.61; ICCCON = 0.70) and corticospinal excitability (ICCSOC = 0.59; ICCCON = 0.70) in both generally active individuals and soccer players routinely exposed to sport-related head impacts. Corticomotor inhibition showed lower coefficients of variation than excitability for both groups (InhibSOC = 15.2%; InhibCON = 9.7%; ExcitabSOC = 41.6%; ExcitabCON = 39.5%). No group differences between soccer players and generally active individuals were found on the corticomotor inhibition value (p > 0.05), but levels of corticospinal excitability were significantly lower in soccer players (45.1 ± 20.8 vs 85.4 ± 6.2%Mmax, p < 0.0001). Corticomotor inhibition also showed excellent inter-rater reliability (ICC = 0.87). Conclusions Corticomotor inhibition and corticospinal excitability are stable and maintain good degrees of reliability when assessed over different days in soccer players, despite their routine exposure to head impacts. However, based on intra-group reliability and group differences of the levels of excitability, we conclude that corticomotor inhibition is best suited for the evaluation of neuromuscular alterations associated with head impacts in contact sports.

scholarly journals A Case–Control Study of Tackle-Based Concussion Risk Factors in The National Rugby League

2021 ◽  
Author(s):  
Andrew J Gardner ◽  
Grant Iverson ◽  
Suzi Edwards ◽  
Ross Tucker
Keyword(s):  
Head Injury ◽  
Body Position ◽  
Rugby League ◽  
Rugby Union ◽  
Head Impacts ◽  
Game Activity ◽  
Impact Risk ◽  
Injury Assessment ◽  
Control Study ◽  
Recent Evaluation

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.

Three-Dimensional Model of the Human Eye-Head Saccadic System

1997 ◽  
Vol 77 (2) ◽  
pp. 654-666 ◽  
Author(s):  
Douglas Tweed
Keyword(s):  
Three Dimensional ◽  
Head Movements ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Gaze Shifts ◽  
One Dimensional ◽  
Human Eye ◽  
Saccadic System ◽  
Listing's Law ◽  
Listing’S Law

Tweed, Douglas. Three-dimensional model of the human eye-head saccadic system. J. Neurophysiol. 77: 654–666, 1997. Current theories of eye-head gaze shifts deal only with one-dimensional motion, and do not touch on three-dimensional (3-D) issues such as curvature and Donders' laws. I show that recent 3-D data can be explained by a model based on ideas that are well established from one-dimensional studies, with just one new assumption: that the eye is driven toward a 3-D orientation in space that has been chosen so that Listing's law of the eye in head will hold when the eye-head movement is complete. As in previous, one-dimensional models, the eye and head are feedback-guided and the commands specifying desired eye position eye pass through a neural “saturation” so as to stay within the effective oculomotor range. The model correctly predicts the complex, 3-D trajectories of the head, eye in space, and eye in head in a variety of saccade tasks. And when it moves repeatedly to the same target, varying the contributions of eye and head, the model lands in different eye-in-space positions, but these positions differ only in their cyclotorsion about the line of sight, so they all point that line at the target—a behavior also seen in real eye-head saccades. Between movements the model obeys Listing's law of the eye in head and Donders' law of the head on torso, but during certain gaze shifts involving large torsional head movements, it shows marked, 8° deviations from Listing's law. These deviations are the most important untested predictions of the theory. Their experimental refutation would sink the model, whereas confirmation would strongly support its central claim that the eye moves toward a 3-D position in space chosen to obey Listing's law and, therefore, that a Listing operator exists upstream from the eye pulse generator.

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