The epidemiology of kicking injuries in professional Rugby Union: A 15-season prospective study

Analysing the impact of the 50:22 kick law changes in South African rugby tournaments between 2021 and 2022

Tactical kicking plays a crucial role in rugby union, influencing both attacking and defensive strategies and potentially impacting a team's overall success. The introduction of the 50:22 law requires defensive teams to reposition players to anticipate and counter kicks, thereby reducing the number of players in their defensive front line. This study investigated the impact of the 50:22 kicking law on kicking profiles by comparing the 2021 and 2022 seasons, as well as examining the success rate of 50:22 kicks during the 2022 season in South African rugby union tournaments. A retrospective research design was employed, utilising video-based performance analysis software (Nacsport Scout Plus) for data collection. The analysis encompassed all general play kicks from 177 matches spanning two seasons and tournaments, amounting to a total of 6,479 kicks. Within this dataset, there were 53 successful 50:22 kicks out of 162 attempts. Key findings revealed an upswing in kicks by scrum halves (2021: 20%, 2022: 26%; p = 0.00) and a concurrent decline in kicks by fullbacks (2021: 21%, 2022: 18%; p = 0.01). Notably, there was a significant increase in the percentage of kicks occurring in the fourth quarter of the match (2021: 20%, 2022: 22%; p = 0.01). Furthermore, the study identified a noteworthy increase in the percentage of kicks following a turnover (2021: 2%, 2022: 3%; p < 0.01). In conclusion, this research contributes valuable insights into how the 50:22 law shapes kicking strategies in South African rugby union, shedding light on the shifts in player roles and temporal patterns of kicking within the context of this specific law.

Epidemiology of quadriceps muscle strain injuries in elite male Australian football players

OBJECTIVE

To describe the epidemiology of quadriceps muscle strain injury (QMSI) in elite Australian Football League (AFL) players, explore recovery milestones and determine whether recovery is impacted by factors such as injury type (index vs. re-injury), the primary muscle injured and the mechanism of injury.

MEASURES

All QMSI data reported to the Soft Tissue Injury Registry of the AFL from the 2014 to 2020 seasons were evaluated. Player demographic data, circumstances of injury, MRI reports and recovery outcomes following injury were extracted. Descriptive statistics and frequency distributions are presented. Recovery outcomes for injury type, primary muscle injured and the mechanism of injury were compared using univariate analyses.

RESULTS

There were 164 QMSIs from 122 players reported (134 index; 30 re-injuries). Almost all (91.3%) QMSIs involved the rectus femoris. Half (48.4%) of the QMSIs occurred during kicking and most commonly affected the dominant kicking leg (72%). The majority occurred at training (64.6%). All re-injuries involved the rectus femoris, most occurred from kicking (63.0%) and within 6 months of the preceding injury (70%). The mean return to play (RTP) time was 25.4 days (95%CI = 22.6-28.2) and rectus femoris injuries took around 14 days longer to RTP than vastii injuries (p = 0.001). QMSIs with a kicking mechanism took the longest to RTP of all injury mechanisms.

CONCLUSION

In AFL players, QMSIs occur mostly in the dominant leg from a kicking mechanism. Rectus femoris injuries are more prevalent and result in longer RTP time frames. Re-injuries exclusively involved the rectus femoris, primarily from kicking.

Its not all about sprinting: mechanisms of acute hamstring strain injuries in professional male rugby union—a systematic visual video analysis

Objectives

The mechanisms of hamstring strain injuries (HSIs) in professional Rugby Union are not well understood. The aim of this study was to describe the mechanisms of HSIs in male professional Rugby Union players using video analysis.

Methods

All time-loss acute HSIs identified via retrospective analysis of the Leinster Rugby injury surveillance database across the 2015/2016 to 2017/2018 seasons were considered as potentially eligible for inclusion. Three chartered physiotherapists (analysts) independently assessed all videos with a consensus meeting convened to describe the injury mechanisms. The determination of the injury mechanisms was based on an inductive process informed by a critical review of HSI mechanism literature (including kinematics, kinetics and muscle activity). One of the analysts also developed a qualitative description of each injury mechanism.

Results

Seventeen acute HSIs were included in this study. Twelve per cent of the injuries were sustained during training with the remainder sustained during match-play. One HSI occurred due to direct contact to the injured muscle. The remainder were classified as indirect contact (ie, contact to another body region) or non-contact. These HSIs were sustained during five distinct actions—‘running’ (47%), ‘decelerating’ (18%), ‘kicking’ (6%), during a ‘tackle’ (6%) and ‘rucking’ (18%). The most common biomechanical presentation of the injured limb was characterised by trunk flexion with concomitant active knee extension (76%). Fifty per cent of cases also involved ipsilateral trunk rotation.

Conclusion

HSIs in this study of Rugby Union were sustained during a number of playing situations and not just during sprinting. We identified a number of injury mechanisms including: ‘running’, ‘decelerating’, ‘kicking’, ‘tackle’, ‘rucking’ and ‘direct trauma’. Hamstring muscle lengthening, characterised by trunk flexion and relative knee extension, appears to be a fundamental characteristic of the mechanisms of acute HSIs in Rugby Union.