Shoulder injuries in elite rugby union football matches: Epidemiology and mechanisms.

Usman, J., et al, 2015 Read Abstract

Shoulder injuries in elite rugby union football matches: Epidemiology and mechanisms.

Usman, J., et al, 2015

Objectives

Shoulder injuries in rugby union football have been the focus of few in-depth studies, despite their frequency and severity. The study's objective was to describe the incidence, patterns and mechanisms of shoulder injuries in rugby.

Design

Prospective cohort study of shoulder injury incidence and retrospective case-series study of shoulder injury mechanisms.

Methods

Data were collected from Super Rugby matches from 2005 to 2010 involving elite level adult male rugby players.

Results

7920 player participation hours and 100 shoulder injuries were recorded during 397 Super Rugby matches. The shoulder injury incidence rate was 13 per 1000 player hours (95% confidence interval 10–16). The mean number of days unavailable for selection due to these injuries was 37 (95% confidence interval 25–54). Tacklers sustained shoulder injuries at a higher rate than ball carriers (Rate Ratio?=?1.7 (95% confidence interval 0.5–5.3)). The most frequently reported injuries were those to the acromio-clavicular joint; dislocations resulted in the greatest amount of missed play. Using video analysis, 47 of the 100 shoulder injury events were successfully identified and analyzed. The main mechanisms of shoulder injury were contact with the ground with the shoulder/arm in horizontal adduction, flexion, and internal rotation; and impact to the lateral aspect of the shoulder with the elbow flexed and arm at the side.

Conclusions

Direct impact to the shoulder, either through player-to-player contact or contact with the ground, is the main cause of shoulder injury. Methods to reduce injury risk, such as shoulder pads and tackle skills, require consideration.

http://www.jsams.org/article/S1440-2440(14)00146-7/references

Injury and biomechanical perspectives on the rugby scrum: A review of the literature.

Trewartha, G.,et al, 2015 Read Abstract

Injury and biomechanical perspectives on the rugby scrum: A review of the literature.

Trewartha, G.,et al, 2015

Introduction and Objectives:

By generating repetitive high-energy impacts (during the engagement phase) and intense sustained loads (during the sustained push phase) under unstable conditions [1], the Rugby Union scrum has been indicated as a possible risk factor for degenerative spinal injuries for forward players, and has been associated with ~40% of all catastrophic injuries in rugby [2]. However, little is known about how these external loading conditions translate into internal stresses on the spinal structures. The aim of this study was to investigate the biomechanics of cervical spine injury during rugby activities using an integrative approach: in-vivo and in-vitro experiments combined with musculoskeletal modelling.

Methods:

Three levels of analysis (Levels 1-3) were integrated. Level 1 was a biomechanical study of scrummaging (N=9 experienced rugby forwards) including motion capture (Oqus, Qualisys, Sweden), force measurement (force plates: Kistler 92876BA, Switzerland; and instrumented scrum machine, [1]), and EMG of neck and trunk muscles (Delsys Trigno, Delsys Inc, USA), carried out to assess the external kinematic and kinetic conditions acting on front row players. The subsequent phases of scrummaging, initial engagament (impact and shock absorption) and sustained push, were observed. Level 2 developed a bespoke musculoskeletal model (Rugby Model, [3]), consisting of 27 anatomical segments, 26 joints, 78 cervical muscles, and 11 torque actuators, in OpenSim (OpenSim 3.2, SimTK, USA). The Rugby Model was driven by the experimental data from Level 1 and was used to estimate joint dynamics, with a specific interest in cervical joint motions and moments. Level 3 performed an in-vitro laboratory experiment to study the injury mechanisms of porcine cervical spines subjected to impact loading conditions similar to those during scrummaging. Load (2 load cells: SLC41/005000, RDP Electronics Ltd, UK) and deformations caused by impacts (mass of 12.86 kg dropped from a height of 250 mm to give an impact velocity of ~2.2 m/s) were measured in a custom made impact rig, and highspeed videos (2 Fastcam SA3, Photron Europe Ltd, UK) were used to investigate the mechanisms of injury through digital image correlation (Vic-3D 2009.1.0, Correlated Solutions Inc, USA).

Results:

Results from the biomechanical analysis confirmed that the load acting on the players, especially during the initial engagement, was of a considerable magnitude (~2.8 kN compression force in single-player machine scrummaging). Muscle activation patterns were affected by scrummaging conditions (e.g. machine vs. contested scrummaging; ‘Crouch-touch-set’ vs. ‘Crouch-bind-set’ sequence) and phases of the scrum (e.g. pre-engagement vs. engagement vs. sustaned push). For example, the activity of the erector spinae was significantly lower (in excess of 65%) in machine scrummaging than in contested scrummaging, and the activation of sternocleidomastoid and upper trapezius through pre-engagement and engagement were higher in the current ‘Crouch-bind-set’ technique than in the past ‘Crouchtouch- set’ one. The computational musculoskeletal model highlighted an antiphase change in movement and loading patterns between the upper and lower cervical levels (i.e. flexion load on the lower vertebrae and extension on the upper vertebrae), and resulted in a “flattening” of the lordotic cervical curve during the impact phase. The present findings do not provide direct evidence for injury mechanisms but seem in line with the patterns of injury that previous authors have described in relation with scrum-related neck traumas [2]. The patterns of strain, load and resulting damages on the cervical structures of the impacted porcine specimens were also similar to those clinically observed in injured players, with the caudal vertebrae (C4-C6) more prone to damages (6 out of 8 specimens) as a consequence of the impact. Fractures resulted from tension in the vertebral bodies due to first order buckling of the cervical spine in extension. The mean maximum load in the cranial and caudal load cells was 5.8±2.0 kN and 6.0±2.1 kN and was reached at a time of 5.1±1.0 ms and 5.6±1.1 ms after impact, respectively.

http://opus.bath.ac.uk/45784/

Preventing non-contact injuries in professional men's rugby union: A brief review.

Green, T., 2015 Read Abstract

Preventing non-contact injuries in professional men's rugby union: A brief review.

Green, T., 2015

The incidence of injury in the sport of rugby union is one of the highest observed amongst all professional team sports. The aim of this review was to identify the incidence, etiology, and epidemiology of the three most significant, non-contact (i.e. preventable) injuries in professional rugby union, and to present methods to address the modifiable risk factors associated with these injuries. The information presented in this article was gathered from peer-reviewed articles relevant to the topic that were yielded from a systematic search using Google Scholar. Preventable injuries of significance in professional rugby union include anterior cruciate ligament (ACL) injury, hamstring injury, and lateral ankle ligament injury. The incidence and severity of these injuries can be reduced with the implementation of an injury prevention program that is targeted towards fatigue management; improving warm up strategies during matches; increasing hamstring: quadriceps strength ratio; improving balance and proprioception, and trunk and lumbopelvic stability; teaching safe and effective landing technique; and increasing flexibility.

http://espace.library.uq.edu.au/collection/UQ:3829?tpl=4&rows=1000&pager_row=0

The international rugby board (IRB) pitch side concussion assessment trial: A pilot test accuracy study.

Fuller, G. W.,et al , 2015 Read Abstract

The international rugby board (IRB) pitch side concussion assessment trial: A pilot test accuracy study.

Fuller, G. W.,et al , 2015

BACKGROUND:

'On the field and on the run' assessments of head impact events in professionalrugby have resulted in a high proportion of players subsequently diagnosed with confirmed concussion not leaving the field of play at the time of injury. The International Rugby Board (IRB) consequently developed a process to support team doctors in the recognition and management ofplayers at risk of concussion, including development of a multimodal assessment instrument-the Pitch Side Concussion Assessment (PSCA) tool.

METHODS:

This was a pilot cohort study designed to determine the feasibility of assessing the accuracy of the IRB PSCA tool in elite male rugby. The study population comprised consecutiveplayers identified with a head impact event with the potential to result in concussion during eight international/national competitions. Players were assessed off field by match-day or team doctors, following a temporary substitution. The accuracy of the PSCA tool was measured against a reference standard of postmatch confirmed concussion, based on clinical judgement aided by an established concussion support instrument.

RESULTS:

A total of 165 head injury events with the potential to cause concussion were included in the study. The PSCA tool demonstrated a sensitivity of 84.6% (95% CI 73.5% to 92.4%) and a specificity of 74% (95% CI 64.3% to 82.3%) to identify players subsequently diagnosed with confirmed concussion. The negative predictive value was 88.1% (95% CI 79.2% to 94.1%); the positive predictive value was 67.9% (95% CI 56.6% to 77.8%). There were no major barriers identified that would prevent the evaluation of the PSCA process or tool in a future large-scale study.

CONCLUSIONS:

This pilot study has provided the first preliminary estimates for the performance of the PSCA tool, suggesting a potentially favourable balance between positive and negative predictive values. The study has also offered a strong basis to conduct a further larger trial, providing information for sample size calculations and highlighting areas for methodological development.

http://www.ncbi.nlm.nih.gov/pubmed/24997205

Physiologically based GPS speed zones for evaluating running demands in Women’s rugby sevens.

Clarke, A. C., et al , 2015 Read Abstract

Physiologically based GPS speed zones for evaluating running demands in Women’s rugby sevens.

Clarke, A. C., et al , 2015

High-speed running (>5 m · s?¹) is commonly reported in men's rugby union and sevens; however, the appropriateness of using the same speed threshold for Women's Rugby Sevens players is unclear, and likely underestimates the degree of high-intensity exercise completed by female players. The aim of this study was to establish, for international Women's Rugby Sevens players, a physiologically defined threshold - speed at the second ventilatory threshold (VT(2peed)) - for the analysis of high-intensity running, using mean and individualised thresholds. Game movement patterns (using 5 Hz GPS) of 12 international Women's Rugby Sevens players (23.5 ± 4.9 ears, 1.68 ± 0.04 m, 68.2 ± 7.7 kg; mean ± s) were collected at an international tournament. Seven of these players also completed a treadmill VO(2max) test to estimate VT(2speed). Compared to the mean VT(2speed) threshold (3.5 m · s?¹), the industry-used threshold of 5 m · s?¹ underestimated the absolute amount of high-intensity running completed by individual players by up to 30%. Using an individualised threshold, high-intensity running could over- or underestimating high-intensity running by up to 14% compared to the mean VT(2peed) threshold. The use of individualised thresholds provides an accurate individualised assessment of game demands to inform the prescription of training.

 

 http://www.ncbi.nlm.nih.gov/pubmed/25510337

 

Influence of physical qualities on post-match fatigue in rugby league players

Rich D. et al, 2015 Read Abstract

Influence of physical qualities on post-match fatigue in rugby league players

Rich D. et al, 2015

Objectives

This study examined the influence of physical qualities on markers of fatigue and muscle damage following rugby league match-play.

Design

Between subjects design.

Methods

Twenty-one male youth rugby league players (age 19.2?±?0.7 years; height 180.7?±?5.6?cm; body mass 89.9?±?10.0?kg) participated in the study. Yo-Yo intermittent recovery test (level 1), 3 repetition maximum back squat and bench press were assessed prior to 2 competitive fixtures. Neuromuscular fatigue (countermovement jump [CMJ] and plyometric push-up [PP]), and blood creatine kinase (CK) were assessed before and after match-play. During match-play, movements were recorded using microtechnology. Players were divided into high- and low-groups based on physical qualities.

Results

High Yo-Yo and squat performance resulted in greater loads during match-play (p? <?0.05). There were larger reductions in CMJ power in the low Yo-Yo group at both 24 (ES?=??1.83), and 48?h post-match (ES?=??1.33). Despite greater internal and external match loads, changes in CMJ power were similar between squat groups. There were larger increases in blood CK in the low Yo-Yo group at 24 (73% vs. 176%; ES?=?1.50) and 48?h post-match (28% vs. 80%; ES?=?1.22). Despite greater contact loads, the high squat group exhibited smaller changes in blood CK post-match (ES?=?0.25–0.39).

Conclusions

Post-match fatigue is lower in players with well-developed high-intensity running ability, and lower body strength, despite these players having greater internal and external match loads.

http://dx.doi.org/10.1016/j.jsams.2014.01.009.

Understanding mismatches in body size, speed and power among adolescent rugby union players,

Lyndon M et al,(2015), 2015 Read Abstract

Understanding mismatches in body size, speed and power among adolescent rugby union players,

Lyndon M et al,(2015), 2015

Objectives

With adolescent sport increasingly challenged by mismatches in size, new strategies are important to maximize participation. The objectives were to (1) improve the understanding of mismatches in physical size, speed and power in adolescent rugby union players, (2) explore associations between size and performance with demographic, playing-history, and injury profiles, and (3) explore the applicability of existing criteria for age/body mass-based dispensation (playing-down) strategies.

Design

Cross-sectional study.

Methods

Four hundred and eighty-five male community rugby union players were recruited from three Australian states selected to represent community-based U12, U13, U14 and U15 players. Body mass, stature, speed (10, 30, and 40?m sprints) and lower-leg power (relative peak power and relative peak force) were measured. Independent student t-tests, linear regressions and Chi square analyses were undertaken.

Results

Mean values in age groups for size, speed and power masked considerable overlap in the ranges within specific age groups of adolescent rugby players. Only a small proportion of players (approximately 5%) shared the highest and lowest tertiles for speed, relative peak power and body mass. Physical size was not related to injury. The mean body mass of current community rugby union players was above the 75th percentile on normative growth-charts.

Conclusion

The notion that bigger, faster, and more powerful characteristics occur simultaneously in adolescent rugby players was not supported in the present study. Current practices in body mass-based criteria for playing down an age group lack a sufficient evidence for decision-making. Dispensation solely based on body mass may not address mismatch in junior rugby union.

http://dx.doi.org/10.1016/j.jsams.2014.05.012

Scrum injury risk in english professional rugby union.

Taylor, A. E., et al, 2014 Read Abstract

Scrum injury risk in english professional rugby union.

Taylor, A. E., et al, 2014

Objective:

To assess and evaluate the injury risk associated with the scrum in English professional rugby union in the 2011–2012 season.

Design:

Prospective, cohort.

Participants:

Players at English Premiership rugby union clubs.

Outcome measures:

Frequency of team scrum-events per match; incidence (injuries per 1000 player-hours; propensity (injuries/1000 events); risk (days absence per 1000 player-hours and days absence per 1000 events).

Results:

31% of scrums in competitive matches resulted in collapse. Injury incidence associated with collapsed scrum-events (incidence: 8.6 injuries/1000 scrum-events) was significantly higher than those scrums that did not collapse (incidence: 4.1/1000 scrum-events).

Conclusions:

The injury risk associated with collapsed scrum supports the continued focus on reducing scrum collapse through changes in, and strict application of, the laws surrounding the scrum.

 

http://www.englandrugby.com/mm/Document/General/General/01/30/80/08/EnglandProfessionalRugbyInjurySurveillanceProjectReport2013_2014_Neutral.pdf