Quality of life among individuals with rugby-related spinal cord injuries in South Africa: a descriptive cross-sectional study.

OBJECTIVES: Rugby-related spinal cord injuries (SCIs) are rare but life altering and traumatic events. Little is known about the long-term consequences and outcomes of players who have sustained these injuries. This study investigated current quality of life (QoL) and factors associated with QoL, among individuals with rugby-related SCI in South Africa, by using the International Classification of Functioning, Disability and Health (ICF) framework. DESIGN: Descriptive cross-sectional study. SETTING: Rugby-related SCI population of South Africa, as captured in the BokSmart/Chris Burger Petro Jackson Players' Fund database. PARTICIPANTS: Ninety (n=90) of the 102 eligible players on the database agreed to participate in the study. MAIN OUTCOME MEASURE: The relationship between QoL, as measured with the WHO Quality of Life questionnaire (WHOQOL-BREF) and specific independent variables (demographic information, level of independence and participation in various activities and life roles) was investigated. Variables that were significantly associated with QoL in bivariate analyses were included in multiple linear regression analyses. RESULTS: The mean score and SD of the WHOQOL-BREF was 15.1±2.3 arbitrary units. Participation (an ICF framework construct) and income were significantly associated with overall QoL (p<0.001). Participation was the only variable significantly associated with all QoL subdomains (p<0.001). Additionally, number of health concerns, type of healthcare (public vs private) and level of education were significantly associated with various QoL domains (p<0.001). CONCLUSIONS: On average, these individuals with rugby-related SCI presented with higher QoL scores than other comparable SCI studies. However, lower levels of participation and income, certain levels of education, increased health concerns and use of public healthcare were associated with lower levels of QoL. Sporting bodies have a responsibility to optimise player welfare, by acting on the modifiable factors associated with QoL.

Symptoms Of Common Mental Disorders In Professional Rugby: An International Observational Descriptive Study.

The aim of the study was to determine the prevalence of symptoms of common mental disorders among professional rugby players across countries. A cross-sectional analysis of the baseline questionnaires from an ongoing prospective cohort study was conducted. Nine national players' associations and three rugby unions distributed questionnaires based on validated scales for assessing symptoms of common mental disorders. Among the whole study sample (N=990; overall response rate of 28%), prevalence (4-week) of symptoms of common mental disorders ranged from 15% for adverse alcohol use to 30% for anxiety/depression. These findings support the prevalence rates of symptoms of common mental disorders found in previous studies among professional (i. e., elite) athletes across other sports, and suggestions can be made that the prevalence of symptoms of anxiety/depression seems slightly higher in professional rugby than in other general/occupational populations. Awareness of the prevalence of symptoms of common mental disorders should be improved in international rugby, and an interdisciplinary approach including psychological attention should be fostered in the medical care of professional rugby players. Adequate supportive measures to enhance awareness and psychological resilience would lead not only to improved health and quality of life among rugby players but arguably to enhanced performance in rugby.

Forced Retirement from Professional Rugby Union is Associated with Symptoms of Distress.

Rugby has a higher injury burden than other popular sports, such as football. Athletes who are forced to retire as a result of injury are associated with poor mental health. With its high injury burden, professional rugby players might be at risk of mental health conditions associated with injury-related forced retirement. This study aimed to compare mental health between former professional rugby players who were and weren't forced to retire. A questionnaire including the 4DSQ (distress), GHQ-12 (anxiety/depression), PROMIS short-form (sleep disturbance) and AUDIT-C (alcohol misuse) was completed by retired professional players from Ireland, France and South Africa. The questionnaire asked players whether or not they were forced to retire, as well as the reason for retirement. Players forced to retire were more than twice as likely to report symptoms of distress in comparison to those that retired voluntarily (odds ratio: 2.1, 95% confidence interval: 1.2-3.6, p<0.001). None of the other mental health measures (anxiety/depression, sleep disturbance or alcohol misuse) were associated with forced retirement. In conclusion, rugby players that were forced to retire may require support structures and longitudinal monitoring. Future studies should begin monitoring players during their careers to accurately assess the effect of retirement on mental health.

Impact of Fatigue on Positional Movements During Professional Rugby Union Match Play.

PURPOSE: In team sports, fatigue is manifested by a self-regulated decrease in movement distance and intensity. There is currently limited information on the effect of fatigue on movement patterns in rugby union match play, particularly for players in different position groups (backs vs forwards). This study investigated the effect of different match periods on movement patterns of professional rugby union players. METHODS: Global positioning system (GPS) data were collected from 46 professional match participations to determine temporal effects on movement patterns. RESULTS: Total relative distance (m/min) was decreased in the 2nd half for both forwards (-13%, ±8%, ES = very likely large) and backs (-9%, ±7%, ES = very likely large). A larger reduction in high-intensity-running distance in the 2nd half was observed for forwards (-27%, ±16%, ES = very likely medium) than for backs (-10%, ±15%; ES = unclear). Similar patterns were observed for sprint (>6 m/s) frequency (forwards -29%, ±29%, ES = likely small vs backs -13% ±18%, ES = possibly small) and acceleration (>2.75 m/s2) frequency (forwards -27%, ±24%, ES = likely medium vs backs -5%, ±46%, ES = unclear). Analysis of 1st- and 2nd-half quartiles revealed differing pacing strategies for forwards and backs. Forwards display a "slow-positive" pacing strategy, while the pacing strategy of backs is "flat." CONCLUSIONS: Forwards suffered progressively greater performance decrements over the course of the match, while backs were able to maintain performance intensity. These findings reflect differing physical demands, notably contact and running loads, of players in different positions.

Preseason Functional Movement Screen Component Tests Predict Severe Contact Injuries in Professional Rugby Union Players.

Tee, JC, Klingbiel, JFG, Collins, R, Lambert, MI, and Coopoo, Y. Preseason Functional Movement Screen component tests predict severe contact injuries in professional rugby union players. J Strength Cond Res 30(11): 3194-3203, 2016-Rugby union is a collision sport with a relatively high risk of injury. The ability of the Functional Movement Screen (FMS) or its component tests to predict the occurrence of severe (≥28 days) injuries in professional players was assessed. Ninety FMS test observations from 62 players across 4 different time periods were compared with severe injuries sustained during 6 months after FMS testing. Mean composite FMS scores were significantly lower in players who sustained severe injury (injured 13.2 ± 1.5 vs. noninjured 14.5 ± 1.4, Effect Size = 0.83, large) because of differences in in-line lunge (ILL) and active straight leg raise scores (ASLR). Receiver-operated characteristic curves and 2 × 2 contingency tables were used to determine that ASLR (cut-off 2/3) was the injury predictor with the greatest sensitivity (0.96, 95% confidence interval [CI] = 0.79-1.0). Adding the ILL in combination with ASLR (ILL + ASLR) improved the specificity of the injury prediction model (ASLR specificity = 0.29, 95% CI = 0.18-0.43 vs. ASLR + ILL specificity = 0.53, 95% CI = 0.39-0.66, p ≤ 0.05). Further analysis was performed to determine whether FMS tests could predict contact and noncontact injuries. The FMS composite score and various combinations of component tests (deep squat [DS] + ILL, ILL + ASLR, and DS + ILL + ASLR) were all significant predictors of contact injury. The FMS composite score also predicted noncontact injury, but no component test or combination thereof produced a similar result. These findings indicate that low scores on various FMS component tests are risk factors for injury in professional rugby players.

10 km running performance predicted by a multiple linear regression model with allometrically adjusted variables.

The aim of this study was to verify the power of VO2max, peak treadmill running velocity (PTV), and running economy (RE), unadjusted or allometrically adjusted, in predicting 10 km running performance. Eighteen male endurance runners performed: 1) an incremental test to exhaustion to determine VO2max and PTV; 2) a constant submaximal run at 12 km·h-1 on an outdoor track for RE determination; and 3) a 10 km running race. Unadjusted (VO2max, PTV and RE) and adjusted variables (VO2max0.72, PTV0.72 and RE0.60) were investigated through independent multiple regression models to predict 10 km running race time. There were no significant correlations between 10 km running time and either the adjusted or unadjusted VO2max. Significant correlations (p < 0.01) were found between 10 km running time and adjusted and unadjusted RE and PTV, providing models with effect size > 0.84 and power > 0.88. The allometrically adjusted predictive model was composed of PTV0.72 and RE0.60 and explained 83% of the variance in 10 km running time with a standard error of the estimate (SEE) of 1.5 min. The unadjusted model composed of a single PVT accounted for 72% of the variance in 10 km running time (SEE of 1.9 min). Both regression models provided powerful estimates of 10 km running time; however, the unadjusted PTV may provide an uncomplicated estimation.

The economic burden of time-loss injuries to youth players participating in week-long rugby union tournaments.

OBJECTIVES: Rugby Union ("rugby") is a popular sport with high injury risk. Burden of injury is described by the incidence and severity of injury. However reports have ignored the monetary cost of injuries. Therefore the aim of this study was to describe the monetary cost associated with youth rugby injuries. DESIGN: This descriptive study quantified medical treatments of injured players at the South African Rugby Union Youth tournaments in 2011/2012 and the days of work parents missed as a result of the injuries. A health insurer used these data to calculate associated costs. METHODS: Legal guardians of the 421 injured players were contacted telephonically on a weekly basis until they returned to play. Treatments costs were estimated in South African Rands based on 2013 insurance rates and converted to US$ using purchasing power parities. RESULTS: Of the 3652 players, 2% (n=71) sought medical care after the tournament. For these players, average treatment costs were high (US$731 per player, 95% CI: US$425-US$1096), with fractures being the most expensive type of injury. Players with medical insurance had higher costs (US$937, 95% CI: US$486-US$1500) than those without (US$220, 95% CI: US$145-US$302). CONCLUSIONS: Although a minority of players sought follow-up treatment after the tournaments, the cost of these injuries was high. Players without medical insurance having lower costs may indicate that these players did not receive adequate treatment for their injuries. Injury prevention efforts should consider injuries with high costs and the treatment of players without medical insurance.

Tackle-related injury rates and nature of injuries in South African Youth Week tournament rugby union players (under-13 to under-18): an observational cohort study.

OBJECTIVES: The tackle situation is most often associated with the high injury rates in rugby union. Tackle injury epidemiology in rugby union has previously been focused on senior cohorts but less is known about younger cohorts. The aim of this study was to report on the nature and rates of tackle-related injuries in South African youth rugby union players representing their provinces at national tournaments. DESIGN: Observational cohort study. SETTING: Four South African Youth Week tournaments (under-13 Craven Week, under-16 Grant Khomo Week, under-18 Academy Week, under-18 Craven Week). PARTICIPANTS: Injury data were collected from 3652 youth rugby union players (population at risk) in 2011 and 2012. OUTCOME MEASURES: Tackle-related injury severity ('time-loss' and 'medical attention'), type and location, injury rate per 1000 h (including 95% CIs). Injury rate ratios (IRR) were calculated and modelled using a Poisson regression. A χ(2) analysis was used to detect linear trends between injuries and increasing match quarters. RESULTS: The 2012 under-13 Craven Week had a significantly greater 'time-loss' injury rate when compared with the 2012 under-18 Academy Week (IRR=4.43; 95% CI 2.13 to 9.21, p<0.05) and under-18 Craven Week (IRR=3.52; 95% CI 1.54 to 8.00, p<0.05). The Poisson regression also revealed a higher probability of 'overall' ('time-loss' and 'medical attention' combined) and 'time-loss' tackle-related injuries occurring at the under-13 Craven Week. The proportion of 'overall' and 'time-loss' injuries increased significantly with each quarter of the match when all four tournaments were combined (p<0.05). CONCLUSIONS: There was a difference in the tackle-related injury rate between the under-13 tournament and the two under-18 tournaments, and the tackle-related injury rate was higher in the final quarter of matches. Ongoing injury surveillance is required to better interpret these findings. Injury prevention strategies targeting the tackle may only be effective once the rate and nature of injuries have been accurately determined.

An evidence-driven approach to scrum law modifications in amateur rugby played in South Africa.

BACKGROUND: In 2012, the South African Rugby Union (SARU) approved a new set of scrum laws for amateur rugby played in the country, to be implemented at the start of the 2013 rugby season. These law changes were primarily based on the relatively high proportion of scrum-related catastrophic injury data collected as part of the BokSmart National Rugby Safety Programme (BokSmart) over the preceding 4 years (2008-2011). AIM: To describe the scrum-related catastrophic injury data in South Africa over the past 5 years (2008-2012), and to discuss how this evidence justifies the change in the Amateur Scrum Laws to make this aspect of the game safer in South Africa. METHODS: Catastrophic injury data were collected through BokSmart at amateur and professional levels, during training and matches over 5 years (2008-2012). RESULTS: The scrum phase accounted for 33% (n=20 of 60) of all catastrophic injuries between 2008 and 2012. Eighteen of the 20 scrum injuries (90%) were confirmed as acute spinal cord injuries, with 13 of these being permanent injuries. For the scrum injury mechanisms that were provided (n=19), 'impact on the engagement' was the most frequently reported (n=11 of 19, 58%), followed by 'collapsed scrum' (n=7 of 19, 37%) and 'popping out' (n=1 of 19, 5%). CONCLUSIONS: Based on these scrum-related catastrophic injury data, a change in the Amateur Scrum Laws of South African Rugby was justified. The main purpose of these scrum law changes is to reduce the number of scrum-related catastrophic injuries in the country, by minimising the opportunity for impact injury and subsequent scrum collapse in amateur rugby in South Africa, thereby making this aspect of the game of rugby safer.

The incidence of rugby-related catastrophic injuries (including cardiac events) in South Africa from 2008 to 2011: a cohort study.

OBJECTIVES: To establish an accurate and comprehensive injury incidence registry of all rugby union-related catastrophic events in South Africa between 2008 and 2011. An additional aim was to investigate correlates associated with these injuries. DESIGN: Prospective. SETTING: The South African amateur and professional rugby-playing population. PARTICIPANTS: An estimated 529 483 Junior and 121 663 Senior rugby union ('rugby') players (population at risk). OUTCOME MEASURES: Annual average incidences of rugby-related catastrophic injuries by type (cardiac events, traumatic brain and acute spinal cord injuries (ASCIs)) and outcome (full recoveries-fatalities). Playing level (junior and senior levels), position and event (phase of play) were also assessed. RESULTS: The average annual incidence of ASCIs and Traumatic Brain Injuries combined was 2.00 per 100 000 players (95% CI 0.91 to 3.08) from 2008 to 2011. The incidence of ASCIs with permanent outcomes was significantly higher at the Senior level (4.52 per 100 000 players, 95% CI 0.74 to 8.30) than the Junior level (0.24 per 100 000 players, 95% CI 0 to 0.65) during this period. The hooker position was associated with 46% (n=12 of 26) of all permanent ASCI outcomes, the majority of which (83%) occurred during the scrum phase of play. CONCLUSIONS: The incidence of rugby-related catastrophic injuries in South Africa between 2008 and 2011 is comparable to that of other countries and to most other collision sports. The higher incidence rate of permanent ASCIs at the Senior level could be related to the different law variations or characteristics (eg, less regular training) compared with the Junior level. The hooker and scrum were associated with high proportions of permanent ASCIs. The BokSmart injury prevention programme should focus efforts on these areas (Senior level, hooker and scrum) and use this study as a reference point for the evaluation of the effectiveness of the programme.

Muscle activation in the loaded free barbell squat: a brief review.

The purpose of this article was to review a series of studies (n = 18) where muscle activation in the free barbell back squat was measured and discussed. The loaded barbell squat is widely used and central to many strength training programs. It is a functional and safe exercise that is obviously transferable to many movements in sports and life. Hence, a large and growing body of research has been published on various aspects of the squat. Training studies have measured the impact of barbell squat loading schemes on selected training adaptations including maximal strength and power changes in the squat. Squat exercise training adaptations and their impact on a variety of performance parameters, in particular countermovement jump, acceleration, and running speed, have also been reported. Furthermore, studies have reported on the muscle activation of the lower limb resulting from variations of squat depth, foot placement, training status, and training intensity. There have also been studies on the impact of squatting with or without a weight belt on trunk muscle activation (TMA). More recently, studies have reported on the effect of instability on TMA and squat performance. Research has also shown that muscle activation of the prime movers in the squat exercise increases with an increase in the external load. Also common variations such as stance width, hip rotation, and front squat do not significantly affect muscle activation. However, despite many studies, this information has not been consolidated, resulting in a lack of consensus about how the information can be applied. Therefore, the purpose of this review was to examine studies that reported muscle activation measured by electromyography in the free barbell back squat with the goal of clarifying the understanding of how the exercise can be applied.

The influence of peripheral afferent signals on the rating of perceived exertion and time to exhaustion during exercise at different intensities.

This study determined which peripheral variables would better predict the rating of perceived exertion (RPE) and time to exhaustion (TE) during exercise at different intensities. Ten men performed exercises at first lactate threshold (LT1), second lactate threshold (LT2), 50% of the distance from LT1 to LT2 (TT(50%) ), and 25% of the distance from LT2 to maximal power output (TW(25%) ). Lactate, catecholamines, potassium, pH, glucose, V(·)O2, VE, HR, respiratory rate (RR) and RPE were measured and plotted against the exercise duration for the slope calculation. Glucose, dopamine, and noradrenaline predicted RPE in TT(50%) (88%), LT2 (64%), and TW(25%) (77%), but no variable predicted RPE in LT1. RPE (55%), RPE+HR (86%), and RPE+RR (92% and 55%) predicted TE in LT1, TT(50%) , LT2, and TW(25%) , respectively. At intensities from TT(50%) to TW(25%) , variables associated with brain activity seem to explain most of the RPE slope, and RPE (+HR and+RR) seems to predict the TE.

Maximal and submaximal physiological responses to adaptation to deep water running.

The aim of the study was to compare physiological responses between runners adapted and not adapted to deep water running at maximal intensity and the intensity equivalent to the ventilatory threshold. Seventeen runners, either adapted (n = 10) or not adapted (n = 7) to deep water running, participated in the study. Participants in both groups undertook a maximal treadmill running and deep water running graded exercise test in which cardiorespiratory variables were measured. Interactions between adaptation (adapted vs. non-adapted) and condition (treadmill running vs. deep water running) were analysed. The main effects of adaptation and condition were also analysed in isolation. Runners adapted to deep water running experienced less of a reduction in maximum oxygen consumption (VO2max) in deep water running compared with treadmill running than runners not adapted to deep water running. Maximal oxygen consumption, maximal heart rate, maximal ventilation, VO2max at the ventilatory threshold, heart rate at the ventilatory threshold, and ventilation at the ventilatory threshold were significantly higher during treadmill than deep water running. Therefore, we conclude that adaptation to deep water running reduces the difference in VO2max between the two modalities, possibly due to an increase in muscle recruitment. The results of this study support previous findings of a lower maximal and submaximal physiological response on deep water running for most of the measured parameters.

Skeletal muscle telomere length in healthy, experienced, endurance runners.

Measuring the DNA telomere length of skeletal muscle in experienced endurance runners may contribute to our understanding of the effects of chronic exposure to endurance exercise on skeletal muscle. This study compared the minimum terminal restriction fragment (TRF) length in the vastus lateralis muscle of 18 experienced endurance runners (mean age: 42 +/- 7 years) to those of 19 sedentary individuals (mean age: 39 +/- 10 years). The runners had covered almost 50,000 km in training and racing over 15 years. Minimum TRF lengths measured in the muscle of both groups were similar (P = 0.805) and within the normal range. Minimum TRF length in the runners, however, was inversely related to their years spent running (r = -0.63, P = 0.007) and hours spent training (r = -0.52, P = 0.035). Therefore, since exposure to endurance running may influence minimum TRF length, and by implication, the proliferative potential of the satellite cells, chronic endurance running may be seen as a stressor to skeletal muscle.

Comparison of body fatness measurements by near-infrared reactance and dual-energy X-ray absorptiometry in normal-weight and obese black and white women.

The aim of the present study was to compare body fat percent (BF %) using single-site near-IR reactance (NIR) and dual-energy X-ray absorptiometry (DXA) in a cohort of normal-weight (BMI < 25 kg/m2) black (n 102) and white (n 71); and obese (BMI > or = 30 kg/m2) black (n 117) and white (n 41) South African women (18-45 years). NIR-derived BF % was significantly correlated with DXA-derived BF % in all groups: normal-weight black (r 0.55, 95 % CI: 0.40, 0.67, P < 0.001) and white (r 0.69, 95 % CI: 0.53, 0.79, P < 0.001) women; obese black (r 0.59, 95 % CI: 0.46, 0.70, P < 0.001) and white (r 0.56, 95 % CI: 0.30, 0.74, P < 0.001) women. NIR under-predicted BF% compared to DXA in black women (normal-weight, - 4.36 (sd 4.13) % and obese, - 3.41 (sd 3.72) %), while smaller mean differences were observed in white women (normal-weight, - 0.29 (sd 4.19) % and obese, - 0.81 (sd 3.09) %), irrespective of normal-weight or obese status (P < 0.001). In obese subjects, NIR-derived BF % did not measure values greater than approximately 45 %, while the maximum DXA-derived measure was 58 %. In conclusion, although there was a significant relationship between NIR- and DXA-derived BF %, NIR under-predicted BF % in normal-weight and obese black South African women compared to DXA, but to a greater extent in subjects with very high levels of adiposity (>45 %). The results of single-site NIR as a measure of BF % should therefore be interpreted with caution, particularly in women of African descent and in those with very high levels of adiposity.

Metabolic consequences of exercise-induced muscle damage.

Exercise-induced muscle damage (EIMD) is commonly experienced following either a bout of unaccustomed physical activity or following physical activity of greater than normal duration or intensity. The mechanistic factor responsible for the initiation of EIMD is not known; however, it is hypothesised to be either mechanical or metabolic in nature. The mechanical stress hypothesis states that EIMD is the result of physical stress upon the muscle fibre. In contrast, the metabolic stress model predicts that EIMD is the result of metabolic deficiencies, possibly through the decreased action of Ca(2+)-adenosine triphosphatase. Irrespective of the cause of the damage, EIMD has a number of profound metabolic effects. The most notable metabolic effects of EIMD are decreased insulin sensitivity, prolonged glycogen depletion and an increase in metabolic rate both at rest and during exercise. Based on current knowledge regarding the effects that various types of damaging exercise have on muscle metabolism, a new model for the initiation of EIMD is proposed. This model states that damage initiation may be either metabolic or mechanical, or a combination of both, depending on the mode, intensity and duration of exercise and the training status of the individual.

Neuromuscular factors determining 5 km running performance and running economy in well-trained athletes.

This study investigated the effects of the neuromuscular and force-velocity characteristics in distance running performance and running economy. Eighteen well-trained male distance runners performed five different tests: 20 m maximal sprint, running economy at the velocity of 4.28 m s(-1), 5 km time trial, maximal anaerobic running test (MART), and a treadmill test to determine VO2max. The AEMG ratio was calculated by the sum average EMG (AEMG) of the five lower extremity muscles during the 5 km divided by the sum AEMG of the same muscles during the maximal 20 m sprinting. The runners' capacity to produce power above VO2max (MART VO2gain) was calculated by subtracting VO2max from the oxygen demand of the maximal velocity in the MART (V MART). Velocity of 5 km (V 5K) correlated with V MART (r=0.77, p<0.001) and VO2max (r=0.49, p<0.05). Multiple linear regression analysis showed that MART VO2gain and VO2max explained 73% of the variation in V 5K. A significant relationship also existed between running economy and MART VO2gain (r=0.73, p<0.01). A significant correlation existed between V 5K and AEMG ratio during the ground contact phase at the 3 km (r=0.60, p<0.05) suggesting that neural input may affect distance running performance. The results of the present study support the idea that distance running performance and running economy are related to neuromuscular capacity to produce force and that the V MART can be used as a determinant of distance-running performance.

The reliability of the FitroDyne as a measure of muscle power.

The FitroDyne is a device that attaches to conventional resistance-training equipment to measure speed of movement, from which muscle power is calculated. The aim of this study was to quantify the repeatability of the measurement of muscle power with the FitroDyne during squat jump and biceps curl exercises. Thirty male subjects completed 3 trials, each consisting of 6 squat jumps and 6 biceps curls of increasing loads. Upper body and lower body maximum power was predicted from the force-velocity curves derived from the range of weights used for each trial. Maximum power measurements of a squat jump (range, 911- 1,673 W) and biceps curl (range, 45-110 W) had intraclass correlation coefficients (ICC) of R = 0.97 (95% CI, 0.95-0.98) and R = 0.97 (95% CI, 0.95-0.98), respectively. The limits of agreement for the squat jump and biceps curl trials were -17 +/- 96 W and 0.11 +/- 13.90 W, respectively. It may be concluded that muscle power can be measured with a high degree of reliability with the FitroDyne. The limits of agreement need to be considered when data are interpreted.