Original research Does instructional video footage improve tackle technique? Hamish A Kerr 1 , Eric H Ledet 2 , Ashar Ata 1 , Jennifer L Newitt 1 , Matthew Santa Barbara 3 , Milan Kahanda 1 and Erin Sperry Schlueter 1 Abstract There is a high incidence of injury during rugby tackling. Tackle biomechanics are linked to this injury risk. The effect- iveness of educational methods in teaching safe rugby tackling for players of various ages and experience levels has not been elucidated. We hypothesized that watching an educational video on rugby tackling technique would alter lower extremity kinematics and reduce cervical spine and head acceleration during tackling. Kinematics and kinetics of 50 collegiate and high school-aged rugby players were recorded while tackling an opponent in a laboratory setting. Movement of the lower extremity, upper body, and head were quantified with a motion analysis system. Participants were shown video instruction on tackling technique then performed another series of tackles. Data were compared pre- and post-educational intervention. A fixed effects model was used to compare the effect of repetition versus educational intervention. Skilled collegiate players tackled with significantly greater mean knee flexion angle post-educational inter- vention relative to pre-instruction, indicative of better technique. The fixed effects model indicated that video instruction decreased acceleration by a mean 51.8 m/s 2 in collegiate players. However, the effect of repetition was shown to increase peak acceleration by a mean 11.2 m/s 2 . In contrast, the educational intervention resulted in an increased acceleration of 15.4 m/s 2 for high school players, but the effect of repetition was shown to decrease acceleration by a mean of 5.2 m/s 2 . Experienced players respond as expected to video instructional intervention. Repetition may be more important for younger rugby players to learn effective tackling. Keywords Concussion, head acceleration, injury prevention, kinematics, kinetics, rugby union, skill acquisition, youth sport Introduction Participation in men’s and women’s rugby is increasing in the United States with a 350% rise in participation since 2004. 1 As a collision sport, there is an inherent injury risk with participation 2–6 and prevention of potential injury requires understanding of the mechan- isms by which injuries typically occur. 7,8 The tackle is the facet of rugby most frequently asso- ciated with injury at all levels. 6,9–13 Investigations of rugby tackle-related injuries have included review of video footage, which has provided valuable insight into elite rugby participation, often recorded for televi- sion. 10,13–15 In retrospective match video analysis of high level youth rugby, front-on tackles resulted in more concussions and the tackling players’ technique was a key injury risk factor identified. 16 Prospectively, kinematic analysis has been used in the laboratory set- ting to investigate risk for head injury in rugby. 17 Linear and angular head acceleration are the kinetic variables that have historically been most closely linked to concussion, among the most common and serious injuries in rugby. 18,19 The tackle contributes to the highest proportion of concussions and spinal cord injuries in rugby. 13,20,21 Momentum and energy transfer at impact during tackles have also been explored. 14 From these recent investigations, it appears clear that Reviewers: Lyle Micheli (Boston Children’s Hospital, USA) Nicholas Burger (Frost and Sullivan, South Africa) 1 Department of Medicine, Albany Medical Center, Albany, USA 2 Department Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, USA 3 Department Physical Medicine & Rehabilitation, UPMC, Pittsburgh, USA Corresponding author: Hamish A Kerr, Albany Medical College, 724 Watervliet-Shaker Rd, Latham, Albany, NY 12208-3479, USA. Email: kerrh@mail.amc.edu International Journal of Sports Science & Coaching 2018, Vol. 13(1) 3–15 ! The Author(s) 2017 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/1747954117711867 journals.sagepub.com/home/spo