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

Abstract

ObjectivesThe 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.MethodsAll 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.ResultsSeventeen 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.ConclusionHSIs 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.

The architectural characteristics of the hamstring muscles do not differ between male and female elite-level rugby union players

“…In a retrospective study with 275 male soccer players who had sustained HSI; the bicep femoris long head muscle was the most commonly injured (56.5%), followed by the semitendinosus muscle (24.4%), semimembranosus muscle (13.7%), and bicep femoris short head muscle (5.6%) (Crema et al, 2015). In elite-level male rugby union players, a recent study highlighted that only 12% of injuries involve either the biceps femoris short head muscle or semitendinosus muscle (Kerin et al, 2022). To our knowledge, no published literature has reported upon the physiological association between muscle thickness and the risk of HSI.…”

“…A similar injury prevalence has been reported in other rugby union injury surveillance studies (Fuller et al, 2013;Fuller et al, 2017), where HSI were the most common injury type sustained during matches. Both the injury burden and recurrence rate of HSI are high (Kerin et al, 2022).…”

A classification of specific movement skills and patterns during sprinting in English Premier League soccer

“…Although it was beyond the scope of the current study to explore the tactical and technical context why curved sprints occurred, soccer players may perform these in- and out-of possession, such as in ‘overlapping’ situations, maintaining an onside position, and performing ‘recovery’ and ‘covering’ runs [ 21 , 27 , 42 , 43 ]. Additionally, the finding that sprints were generally performed with trunk rotation is noteworthy, and could have important injury implications, due to the propensity to generate greater mechanical loads at the knee with trunk rotation compared to linear running [ 44 ], while trunk rotation has been recently identified as a visual characteristic observed during non-contact running hamstring strain injury inciting events in rugby union [ 29 ]. With this in mind, isolated, traditional track and field based sprinting programmes may not be the most effective training modality in this context, and thus practitioners should ensure their athletes have the physical capacity to tolerate the unique imposed loading associated with curved sprinting [ 45 ].…”

“…It is argued that movement skill, pattern, and contextual information on sprinting to supplement the previously studied high-intensity running [ 16 , 17 , 27 ] would prove to be even more valuable for practitioners working in elite soccer. Due to the increased physical demands, potential performance benefits, and inherent injury risks associated with greater sprinting velocities [ 28 ], examination of specific movements associated with soccer sprinting would be beneficial [ 7 , 29 , 30 ]. A deeper insight into the movement skills and patterns associated with sprinting efforts could be used to assist in drill construction, testing battery selection, and inform physical preparation strategies for soccer players, enabling practitioners to achieve increased specificity and ecological validity [ 20 , 27 , 31 ].…”

Evaluation of performance of key hits using input data, electromyography, and video analysis

“…In the field of physical sports, surface electromyography (EMG) 21,22) or video recording 23,24) has been used to analyze the movements of large muscles such as arms and legs. EMG is commonly used to assess muscle fatigue, and it can be used to quantitatively measure myoelectrical activity non-invasively in real time.…”