Tacklers shoulder abduction and flexion at contact alters when engaging in different front-on, one-on-one tackle instructions from an expert coach

Objectives To ascertain how the three-dimensional shoulder kinematics of tacklers alter when performing four legal types of front-on, one-on-one, rugby-style torso tackles. Design Controlled laboratory study. Methods Three-dimensional motion capture measured the movements of 15 male amateur-level rugby code players (24.3 ± 6.1 years) who were instructed by an expert coach to perform four sets of 10 front-on, one-on-one tackles. Four sets comprised two smother and two dominant tackle: two based on the Australian National Rugby League (NRL) coaching manual (Dominant NRL [DNRL], Smother NRL [SNRL]); and two modifications via increasing the contact height from lower- to mid-torso (Dominant, Torso Stick [DTS]) or from upper- to mid-upper torso with a vertical ‘pop action’ that changes the way the tackler contacted the ball carrier's upper torso (Smother, Pop, Lock [SPL]). Mixed general linear models were applied. Results Greater shoulder abduction, flexion and internal rotation was displayed by the DNRL tackle technique than in any other technique (p < 0.001). At contact, the SNRL and DNRL (p < 0.03) showed greater head-uptrunk contralateral rotation away from the tackle than the SPL. Conclusion Tacklers modified the way they positioned their shoulder joint when engaging in legal front-on, one-on-one tackles with different tackle instructions. More prominent positions of shoulder abduction and flexion, as well as head-uptrunk contralateral rotation were observed when executing the traditional tackle techniques (SNRL, DNRL) as opposed to two variants of these (SPL and DTS). Inclusion of tackle specific coaching instructions provides emerging scientific evidence to support revised coaching tackling technique interventions that might enhance player safety.