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The present study aimed to determine the mechanisms of mild cervical injuries caused by tackling in a rugby union. This study enrolled 137 male players from a Japanese collegiate rugby union club during the 2009-2013 seasons. Twenty-nine (53.7%) of 54 incidents leading to mild cervical injury were identified from match video records and injury data that were reported under the definition of medical attention. In addition, all tackles by players in the same match in which they sustained cervical injury were extracted as a control cohort. All tackles were coded according to eleven characteristics of three tackle phases. Twenty-one tackles were the main events leading to mild cervical injury. The likelihood of tacklerassociated mild cervical injuries was significantly higher when tacklers had no time to face forward at the offside line before tackle situations, tackles with incorrect tackler head positions, and not using arms after initial contact. These results suggest that further investigation is needed to determine specific tackling characteristics considering the three tackle phases and their combined effects. [ABSTRACT FROM AUTHOR]

Rugby union players can be involved in many tackles per game. However, little is known of the regular head loading environment associated with tackling in rugby union. In particular, the magnitude and influencing factors for head kinematics during the tackle are poorly understood. Accordingly, the goal of this study was to measure head motion of a visually unaware ball carrier during a real game tackle to the upper trunk with no direct head contact, and compare the kinematics with previously reported concussive events. Model-Based Image-Matching was utilised to measure ball carrier head linear and angular velocities. Ball carrier componential maximum change in head angular velocities of 38.1, 20.6 and 13.5 rad/s were measured for the head local X (coronal plane), Y (sagittal plane) and Z (transverse plane) axes respectively. The combination of a high legal tackle height configuration and visually unaware ball carrier can lead to kinematics similar to average values previously reported for concussive direct head impacts. [ABSTRACT FROM AUTHOR]

Background: Although improper tackling technique in rugby can affect the outcome of the tackle and lead to head, neck, and shoulder injuries, the effects of the height of the tackle or the side of the leading leg at the time of impact have not been investigated. Hypothesis/Purpose: The purpose was to characterize the trunk orientation at impact during various tackles. It was hypothesized that 3-dimensional motion analysis would be able to capture the critical kinematic differences in the 4 types of tackles studied. Study Design: Controlled laboratory study. Methods: A total of 66 tackles on a tackle bag were recorded among 13 elite rugby players. Four types of tackles were evaluated: the normal shoulder tackle, in which the tackler’s dominant shoulder made impact while the leading foot was on the same side as that shoulder; the low tackle, in which the tackler targeted the lower portion of the tackle bag; the opposite-leg tackle, in which the tackler’s leading leg was on the opposite side as the shoulder making impact; and the low and opposite-leg tackle, which was a combination of the previous 2 types of tackles. The orientation of the trunk at impact was calculated, and 2-way repeated-measures analyses of variance were used to compare the characteristics of these tackles. Results: Trunk inclination at impact was lower in the low tackle than in the normal tackle (P < .01), regardless of the side of the leading leg. Trunk bending to the side of the impacted shoulder was lower in the opposite-leg tackle (P < .01), and these findings were more significant in the normal-height tackles (P < .01). Trunk rotation to the side of the impacted shoulder was lower in the opposite-leg tackles (P < .01) and more significant in the lower-height tackles (P = .03). Conclusion: The 3-dimensional motion capture system was effective in investigating the kinematics of rugby tackling. The kinematics in the low and opposite-leg tackles were significantly different from those in the normal shoulder tackle, which may affect tackle performance and the possible risk of contact injury. Clinical Relevance: When a rugby coach provides tackling instructions to players, it is advantageous to have information about the kinematics of different types of tackles. [ABSTRACT FROM AUTHOR]

This study investigated the influence of repeated high-intensity effort exercise on tackling ability in rugby league players, and determined the relationship between physical qualities and tackling ability under fatigued conditions in these athletes. Eleven semi-professional rugby league players underwent measurements of speed (10 m and 40 m sprint), upperbody strength (4 repetition maximum [RM] bench press and weighted chin-up), upperbody muscular endurance (body mass maximum repetition chin-up, body mass maximum repetition dips), lower-body strength (4RM squat), and estimated maximal aerobic power (multi-stage fitness test). Tackling ability was assessed using a standardized one-on-one tackling test, before, during, and following four bouts of repeated high-intensity effort (RHIE) exercise. The relationship between physical qualities and fatigue-induced decrements in tackling ability were determined using Pearson product moment correlation coefficients. Each cycle of the RHIE protocol induced progressive reductions in tackling ability. A moderate reduction (Effect Size = ~-1.17 ± 0.60, -34.1 ± 24.3%) in tackling ability occurred after the fourth cycle of the RHIE protocol. Players with greater relative lowerbody strength (i.e. 4RM squat/kg) had the best tackling ability under fatigued conditions (r = 0.72, p = 0.013). There were no significant relationships between tackling ability under fatigued conditions and any other physical quality. These findings suggest that lower-body strength protects against fatigue-induced decrements in tackling ability. The development of lower-body strength should be a priority to facilitate the development of robust tackling skills that are maintained under fatigue. [ABSTRACT FROM AUTHOR]

This study examined the influence of a strength and power program on tackling ability in rugby league players. Twenty-four semiprofessional rugby league players (mean±SD age, 23.4±3.1 years) underwent tests of upper-body strength (3 repetition maximum [RM] bench press), lower-body strength (3RM squat), upper-body power (plyometric push-up), and lower-body power (countermovement jump [CMJ]). Muscular strength relative to body mass was also calculated. Tackling ability of the players was assessed using video analysis of a standardized one-on-one tackling drill. The players then underwent 8 weeks of strength and power training as part of their preseason training before being retested. Training resulted in significant (p ≤ 0.01) improvements in absolute and relative measures of squat, bench press, CMJ peak power, and plyometric push-up peak power. The strongest correlates of change in tackling ability were changes in 3RM squat (r = 0.60; p < 0.01) and squat relative to body mass (r = 0.54; p < 0.01). The players with the greatest improvements in 3RM squat and squat relative to body mass (i.e., responders) had significantly greater improvements in tackling ability than nonresponding players (p = 0.04; effect size [ES] ⋅ 0.85). A small, nonsignificant difference (p = 0.20; ES = 0.56) in tackling ability was found between responders and nonresponders for lower-body power. The findings of this study demonstrate that the enhancement of lower-body muscular strength, and to a lesser extent muscular power, contribute to improvements in tackling ability in semiprofessional rugby league players. [ABSTRACT FROM AUTHOR]