Kerr and colleagues [25] observed a significant 40 increase in the tacklers knee joint angle at impact pre- compared to post-video tackling instruction intervention in skilled male and female college players (n=9), yet this was not observed in novice male or female players (n=5). 2009;29(3):3609. Further, it must be stressed that the game of Rugby places demands on technical, tactical and psychological factors over and above those that can be described in a physical time-motion analysis. For example, time-motion analysis does not quantify the impact of being tackled or tackling or the impact and force generated during other intense physical activities such as scrummaging, rucking and mauling. Measuring 3D tackle motion of multi-player tackles and tackles taken to the ground is a feasibility issue with optoelectronic 3D motion capture system due to marker occlusion and concerns about the skin-mounted retroreflective markers. Kawasaki T, Tanabe Y, Tanaka H, Murakami K, Maki N, Ozaki H, et al. Available from: https://www.playrugbyleague.com/media/3179/nrl-coaching-manual-2019.pdf. Most studies did provide sufficient information to replicate their 3D model used to calculate kinematic variables such that four studies reported their joint co-ordinate system definition [22, 23, 27, 28], yet only two studies defined their 3D rotation [27, 28]. Sasaki K, Sato H, Nakamura A, Yamamoto T, Watanabe I, Katsuta T, et al. https://doi.org/10.1080/02640414.2017.1330548. Waterloo: Wiley; 2009. Int J Sports Sci Coaching. The players in a low tackle also increased their trunk rotation and decreased their lateral trunk flexion to the side of impact compared to a normal tackle height [28]. RT and GF made contributions to the interpretation of data and revisions of the manuscript. Int J Sports Sci Coaching. 2018;50(3):6038. right shoulder, right leg), players were observed to decrease their amount of trunk lateral flexion and increase their trunk rotation to the side of the impact shoulder compared to when using the opposite leading leg.

Suzi Edwards. Available from: https://australia.rugby/participate/coach/coaching-resources/coaching-manuals. Gabbett TJ, Jenkins DG, Abernethy B. At impact, when community and university players tackled a bag from a stationary position and engaged with their dominant shoulder, their neck flexion decreased by 5, neck lateral flexion decreased by 6, and trunk lateral flexion increased by 5 compared to their non-dominant shoulder engagement [26]. Quarrie KL, Hopkins WG, Anthony MJ, Gill ND. Fuller CW, Taylor A, Raftery M. Epidemiology of concussion in mens elite Rugby-7s (Sevens World Series) and Rugby-15s (Rugby World Cup, Junior World Championship and Rugby Trophy, Pacific Nations Cup and English Premiership). Work by Schaefer and colleagues [61] in cricket fast bowling (see their Additional file 1: Appendix 1 to 3) illustrates the ideal level of detail of data reduction and analysis methodology required for 3D kinematics research (i.e. The reliability of three-dimensional kinematic gait measurements: a systematic review. Dennison CR, Macri EM, Cripton PA. Mechanisms of cervical spine injury in rugby union: is it premature to abandon hyperflexion as the main mechanism underpinning injury? https://doi.org/10.1136/bjsports-2019-101293. Poor quality reporting of methodological detail complicates the interpretation of study results. These variables are commonly absent from the methodological description of studies. https://doi.org/10.1136/bjsm.2008.050864. Peak shoulder and cervical spine linear accelerations were not altered following a video tackle technique instruction in collegiate players, but cervical spine linear acceleration increased post-intervention in high school players [25]. The frequency of a change in the approach movement of the ball carrier to a cut action was significantly greater in the arm tackle condition than in the shoulder tackle condition (i.e. Other types of 3D motion capture system technology to measure human motion in sport exist, but no 3D motion capture system currently exists that can measure large volumes with high accuracy [42] within a game environment. The paramount importance of this data collection information is exemplified in the parameter sampling frequency. Eligible studies were of moderate (n=1) or high (n=3) risk of bias, due largely to small participant numbers, study design, outcome limitations and the inclusion of questions within the bias of risk assessment not relevant to 3D motion studies that skewed the risk of bias score. For example, Kerr and colleagues [25] did not report their data sampling frequency, the filtering methods of their 3D motion capture data, and utilised a marker suit rather than attaching the markers to the participants skin. A zero-lag, fourth order Butterworth low pass filter was commonly employed (six studies), yet no justification for cutoff frequency selection was provided in any of those studies.

2005;38(4):91929. 2000;32(12):19804. An example of spectral analysis of a ball carrier and tackler within a single trial of a front-on, one-on-one tackle (unpublished data). The impact speed of the ball carrier was found to be higher, though not significantly, when the tackler made contact with the ball carriers upper trunk, as opposed to the ball carriers mid/lower trunk [22]. Vanrenterghem J, Venables E, Pataky T, Robinson MA. https://doi.org/10.1123/ijspp.2014-0381. Hendricks S, Till K, den Hollander S, Savage TN, Roberts SP, Tierney G, et al. 2009;4(4):52133. Clarifying the structure of serious head and spine injury in youth Rugby Union players. Two studies investigated tackle height, which was categorised as either a high or low tackle [22, 28]. These marker sets modelled the thorax as a single segment [47] rather than as a two segment (lumbar and thoracic) spine model that can measure thoracolumbar and lumbopelvic joint angles [48] to quantify a straight back posture. 2017;51(1):517. Ford KR, Myer GD, Hewett TE. Br J Sport Med. Injury risks associated with tackling in rugby union. For example, Kawasaki and colleagues [27, 28] used initial displacement of the markers as the criteria for the time of impact; however, it was not specified which markers were used, nor the threshold value used to define initial displacement (i.e. The results of research by Tanabe and colleagues [27] reported a larger shoulder abduction angle, yet no difference in any other neck, trunk or shoulder angles at contact when compared to a shoulder tackle. Critical factors affecting accuracy such as the number of cameras [41] and marker set [43] were universally reported by studies included in this review. Kinematics of rugby tackling: a pilot study with 3-dimensional motion analysis. J Biomech Eng. When these players used their dominant shoulder to engage in the tackle from a stationary position compared to an in-motion start, they displayed 5 less neck flexion and 3 less trunk lateral flexion [26]. It does not describe the extent of physical force applied during contact within match play. Wu G, Cavanagh PR. Manage cookies/Do not sell my data we use in the preference centre. https://doi.org/10.1177/1747954117711866. Corresponding authors were contacted to provide mean and standard deviations of variables that were in graphical form or when such data could not be located within the publication. Hendricks S, OConnor S, Lambert M, Brown JC, Burger N, Mc Fie S, et al. The effect of technique on tackle gainline success outcomes in elite level rugby union. Google Scholar. Br J Sport Med. 2018;36(6):67990. 2020; Available from: https://www.nrl.com/stats/players/?competition=111&season=2019&stat=3. 2016;49(10):20858. Eur J Sport Sci. Several between-study methodological differences made it challenging and inappropriate to undertake comparisons of findings in this review. The tackle event can be confounded by numerous factors including the number of tacklers performing the tackle, whether the tackle is taken to the ground, the intensity of the tackle and player speed. Wu G, Siegler S, Allard P, Kirtley C, Leardini A, Rosenbaum D, et al. J Strength Cond Res. The speed of changing direction or the rate of acceleration and deceleration and the pathway of running patterns used are not described using traditional video based time-motion analyses. For example, when tackling, a neutral spine or straight back posture is recommended [31] for performance [44] and to reduce [45] head and spinal [46] injury risk. Passive optoelectronic motion capture systems were employed by all studies within this systematic review. 2013;16(4):3539. 2015;15(6):55764. PubMed Tierney GJ, Denvir K, Farrell G, Simms CK. An urgent need for high-quality 3D motion capture studies investigating 3D tackling mechanics in the rugby codes is warranted, ideally using a research framework proposed in this review. Fuller CW, Taylor A, Kemp SPT, Raftery M. Rugby World Cup 2015: World Rugby injury surveillance study. All materials are listed within this manuscript. There were a total of 92 rugby union participants (individual study numbers ranged from 4 [22, 23] to 25 [24]) across the seven eligible studies. One of these studies [25] also included female participants. Article A major shortcoming of this body of work is the failure to report comprehensive information pertaining to participant demographics. The authors read and approved the final version of the manuscript. Technological advances in 3D motion capture technology offer the potential for in-game rugby-style tackle technique to be assessed in future research. This tackle speed would be categorised as slow [36]. Biomechanics and motor control of human movement. Given the study design and methodology limitations, the absence of essential experimental task descriptions (tackle speed, tackle intensity), 3D motion collection and analysis (sampling frequency, 3D model), it was not possible to verify that their coaching intervention altered tackle technique. XXVII Congress of the International Society of Biomechanics; 2019 31 July-4 August 2019; Calgary, Canada; 2019. Cross MJ, Tucker R, Raftery M, Hester B, Williams S, Stokes KA, et al. As a result, please ensure you compete any partly completed modules prior to then. https://doi.org/10.1136/bjsports-2016-096275. All but one study [25], employed a low pass zero-lag fourth order filtering with differing cutoff frequencies. The efficiency of movement is also not described. 2018;18(6):80619. Med Sci Sports Exerc. Copyright International Rugby Board 2011 - 2022 Traditional time-motion analysis describes the main physical activities and most frequent activities that take place during match play. s2, or G (acceleration due to gravity); and other variables measured were reported as either percentage (%), kilonewtons (kN), seconds (s), metres per second (m/s) or body weight (BW). Fitzpatrick AC, Naylor AS, Myler P, Robertson C. A three-year epidemiological prospective cohort study of rugby league match injuries from the European Super League. Article Brain Inj. J Manipulative Physiol Ther. A total of 1498 articles were identified through the initial search strategy (see Fig.1), from which 833 duplicates were identified and removed. https://doi.org/10.1136/jech.52.6.377. Previous grant funding includes the NSW Sporting Injuries Committee, the Brain Foundation (Australia), an Australian-American Fulbright Commission Postdoctoral Award, a Hunter New England Local Health District, Research, Innovation and Partnerships Health Research & Translation Centre and Clinical Research Fellowship Scheme, and the Hunter Medical Research Institute (HMRI), supported by Jennie Thomas, and the HMRI, supported by Anne Greaves. Sports Biomech. Peck KY, Johnston DA, Owens BD, Cameron KL. Plos One. 1991;10(5):57587. how far the markers were required to move to define the temporal event). For all 25 scores that were not agreed upon by the two raters, the risk of bias scores from the third reviewer were used to reach a consensus. Int J Sports Physiol Perform. The effect of walking speed on the gait of typically developing children. 2012;30(12):121524. Residual analysis [50] of raw 3D position of head markers during a front-on, one-on-one torso tackle at a slow tackle speed (unpublished) showed a median frequency of 12 Hz (range 9 to 14 Hz); recommending a cutoff frequency 15 Hz should be used when using a zero-lag, fourth order Butterworth low pass filter. 2020;54(10):56672. New York: Taylor & Francis; 2008. p. 3352. Davis RB, unpuu S, Tyburski D, Gage JR. A gait analysis data collection and reduction technique. Speed of the tackler can be influenced by the experimental task instructions such as tackle intensity, approach distance (greater distance, higher speed), number of tacklers involved in the tackle, the surface and the actions of the ball carrier and other opponents in the tackle. https://doi.org/10.1260/174795409790291402. Medical Education. 2018;13(1):315. When these players performed this task at a low tackle height, compared to normal tackle height, they increased their forward trunk inclination angle by approximately 15, irrespectively of whether they used their left or right leg as their leading leg at impact. https://doi.org/10.1016/0021-9290(95)00017-C. Wood GA, Jennings LS. In vivo lumbo-sacral forces and moments during constant speed running at different stride lengths. Considering the emergence of female participation in the rugby codes [29], further epidemiological research is required to determine if, and the extent to which, limited technical tackling training and/or experience [29, 30] may contribute to any disparity in injury rates between male and female players. Other variables of interest included in the eligible studies such as head acceleration [22, 23, 25] or player speed [22, 23] are reported in Table5. Only limited laboratory-based evidence using passive optoelectronic 3D motion capture currently exists on the 3D biomechanics of tackling techniques to guide coaches and clinicians on the most optimal method to execute a tackle to reduce the injury risk and optimise performance for both the ball carrier and tackler. California Privacy Statement, 2012;20(2):86104. Players also vary in terms of strength, power and speed and indeed these individual differences and other differences in terms of courage, and durability all need to be borne in mind when planning training and practice. The influence of speed on tackle technique was highlighted in a study using a tackle bag with the tackler in a motion rather than in a stationary position. For example, using different methods of joint modelling [56], filtering [57] and definition of kinematic variables [58] have been shown to produce varying results.

Sports Med - Open 7, 39 (2021). https://doi.org/10.1177/0363546518781808. Knee flexion, but not hip flexion, was found to be altered in skilled, but not novice players, after watching a tackling instruction video [25]. College and professional players forward trunk inclination angle at impact with a tackle bag was significantly influenced by the hip abduction angle of the leading leg and trunk rotation away from the contacted shoulder two steps prior to impact [28]. J Biomech. right shoulder, right leg) or opposite side (i.e. Consensus on a video analysis framework of descriptors and definitions by the Rugby Union Video Analysis Consensus group. McIntosh AS, Savage TN, McCrory P, Frechede BO, Wolfe R. Tackle characteristics and injury in a cross section of rugby union football. Model-based image matching is one such emerging technology that uses multiple 2D video camera views and applies a multibody skeletal model to estimate in-game 3D player kinematics [51] or 3D head velocity during a tackle in rugby union [52] and American football [53]. Video analysis of concussion injury mechanism in under-18 rugby. 2015;10(6):6816.

https://doi.org/10.1016/j.gaitpost.2008.09.003. A preliminary video analysis of concussion in the National Rugby League. League NR. Res Sports Med. PubMed This research framework has four key research recommendations: (i) participant demographic information, (ii) experimental task design information, (iii) 3D motion capture data specifications, and (iv) 3D data reduction and analysis. He has received research funding from the National Rugby League (NRL) for the Retired Professional Rugby League Players Brain Health Research Program. https://doi.org/10.1249/MSS.0000000000001461. Three studies attempted to understand whether upper limb injury risk was altered when engaging with dominant or non-dominant shoulder when tackling a bag [26] or differed with the type of one-on-one tackle [27]. https://doi.org/10.1136/bmj.b2535. Article A significantly lower mean impact force of a tackler when tackling a tackle bag was shown in the stationary start condition in the non-dominant shoulder versus a dominant shoulder, and in the dominant shoulder in the stationary start condition versus the in-motion start condition [26]. van der Kruk E, Reijne MM. This was found to result in decreased total contact force and longer contact duration. 2011;14(3):2105. Tierney GJ, Joodaki H, Krosshaug T, Forman JL, Crandall JR, Simms CK. Grood ES, Suntay WJ. https://doi.org/10.1016/j.jbiomech.2012.06.029. 1983;105(2):13644. https://doi.org/10.1016/S0021-9290(01)00222-6. The effect of tackler technique on head injury assessment risk in elite rugby union. Moher D, Liberati A, Tetzlaff J, Altman DG. Tierney GJ, Gildea K, Krosshaug T, Simms CK. [cited 2019 25 October]. Tanabe Y, Kawasaki T, Tanaka H, Murakami K, Nobuhara K, Okuwaki T, Kaneko K. The kinematics of 1-on-1 rugby tackling: a study using 3-dimensional motion analysis. Correspondence to J Biomech. PubMed Central 2019;49(10):155974. TT made contributions to the design of the study and interpretation of data. Risks associated with significant head impact events in elite rugby union. 2017; Available from: https://www.world.rugby/development/player-numbers?lang=en. Specifically, it is not known whether (i) the Nyquist sampling theorem was violated, (ii) the lack of filtering introduced extraneous noise in the data, (iii) the relative movement between the marker suit and skin decreased the reliability of the data, (iv) the magnitude of the error when modelling the 3D body segments and joint centres when using suit markers that roughly estimate the underlying anatomical landmark in participants of differing anthropometric dimensions, (v) the study used the joint coordinate system of Grood and Suntay [59] or the International Society of Biomechanics [60], and/or (vi) the Cardan sequence of rotation to express inter-segment joint angles was used and the sequence of rotation selected if used. Privacy Whether the tackle is taken to the ground [24, 25] (41% of tackles in rugby union [33]) or not [26] is often unreported [22, 23, 27, 28]. Coaching manuals present different tackle techniques between the rugby codes [31, 32]. Arm tackles are attributed to the most number of shoulder injuries when tackling [36] and occur more frequently when the ball carrier changes their running direction [27]. Andrew Gardner, Ph.D. serves as a scientific advisor for hitIQ, Ltd. CAS In simple terms, time-motion studies use non-invasive methods of measurement such as video tracking in recording the motion and movement of a player or players, and the duration of a given bout of activity during match play. https://doi.org/10.1177/1941738113487165. One-on-one, front-on [22,23,24,25, 27] or side-on [27] contact between a tackler and a ball carrier was used in five studies [22,23,24,25, 27], while three studies used a tackler impacting a tackle bag or bump pad [24, 26, 28]. These methodological shortcomings render interpretation of the accuracy of the kinematic data impossible to ascertain. Analysis of ball carrier head motion during a rugby union tackle without direct head contact: a case study. Time-motion analysis provides an objective measure and evaluation of the physical demands of the game of Rugby. Google Scholar. 2022 BioMed Central Ltd unless otherwise stated. 2012;45(14):24449. A joint coordinate system for the clinical description of three-dimensional motions: application to the knee. Level of play included high school [25], community [26], collegiate [25,26,27], semi-elite [24] and professional [22, 23, 27, 28]. J Epidemiol Community Health. PubMed McGinley JL, Baker R, Wolfe R, Morris ME. Whether at impact the leading leg was the same side (i.e. 2010;42(5):97784. Marker sets need to be able to measure key 3D outcome variables in tackle research. https://doi.org/10.1097/00005768-200012000-00002. Seminati E, Cazzola D, Preatoni E, Trewartha G. Specific tackling situations affect the biomechanical demands experienced by rugby union players. 2017;16(1):5875. One study was categorised as moderate risk of bias [23] and six studies as high risk of bias. A pilot longitudinal study of 3-dimensional head and neck kinematics during functional tasks in individuals with chronic idiopathic neck pain either wait-listed for or receiving chiropractic spinal manipulative therapy with exercise. One study was focused on methodology to identify the most appropriate data reduction method when processing peak acceleration recorded from a triaxial accelerometer device unit during a tackle [24]. Boser QA, Valevicius AM, Lavoie EB, Chapman CS, Pilarski PM, Hebert JS, et al. A systematic review of 3D biomechanics of rugby tackle techniques and risk of injury. Moresi MP, Bradshaw EJ, Greene DA, Naughton GA. 2009;339(jul21 1):b2535. These data collection parameters were met for all but one study [25]. J Biomech. J Sports Sci. Accuracy of human motion capture systems for sport applications; state-of-the-art review. https://doi.org/10.1249/mss.0b013e318149332d. [cited 2020 4 Nov]. https://doi.org/10.1136/bmjsem-2015-000053. Eur J Sport Sci. 2018;17(1):3347. Seven articles met inclusion criteria. Variations in the data reduction and analysis methodology can alter results. 2018;13(1):1625. 2020;6(1):e000638. Edwards, S., Lee, R., Fuller, G. et al. Cookies policy. Appl Sci. J Sci Med Sport. Biomechanical evaluation of movement in sport and exercise: The British Association of Sport and Exercise Sciences Guide. 2020;44(4):24562. 2013;5(4):32733. Eligible studies investigated either one-on-one, front-on [22, 24, 25, 27] or side-on [27] contact between a tackler and a ball carrier or a tackler impacting a tackle bag or bump pad [24, 26, 28]. When extracting the data, the summary measures of the means and standard deviations were reported. Four studies examined how modification of the tackle technique alters a players mechanics during a tackle. 2018;46(10):251420. Definitions of the time of temporal events varied between studies. To improve the clarity of the role of the leg drive within the tackle, Kawasaki and colleagues [28] investigated whether using a different leading leg when contacting a tackle bag altered the trunk mechanics of the tackler. Springer Nature. Ann Biomed Eng. Tierney GJ, Lawler J, Denvir K, McQuilkin K, Simms CK. Experimental task characteristics varied widely in the eligible articles (Table3). An alternative technology measuring head acceleration is wearable sensors such as instrument mouthguards [55]. Br J Sport Med. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. https://doi.org/10.1177/1747954117711867. McIntosh AS, McCrory P, Comerford J. Validation and comparison of instrumented mouthguards for measuring head kinematics and assessing brain deformation in football impacts. RL and MB contributed to the data extraction and analysis.

2020;48(11):258098. Winter DA. One underpowered study investigated the effectiveness of a coaching intervention (i.e. Bearman M, Dawson P. Qualitative synthesis and systematic review in health professions education. The contact time duration was significantly reduced during tackling in the in-motion start, dominant shoulder tackle condition compared to the stationary start, dominant shoulder tackle condition, as well as for the stationary start, dominant shoulder tackle condition than the stationary start, non-dominant shoulder [26]. Cervical angle reported by one study [25] was a three-point 2D planar angle that cannot measure the 3D spinal motion. 2019;9(4):726. https://doi.org/10.3390/app9040726. Wundersitz DW, Gastin PB, Robertson SJ, Netto KJ. https://doi.org/10.1136/bjsports-2012-091257. One limitation of focusing solely on the one-on-one tackle is that the results cannot be extrapolated to multi-player tackles, which is the most common tackling situation in rugby league [10] and rugby union [36] match play. Could lowering the tackle height in rugby union reduce ball carrier inertial head kinematics? Playing position was only reported in three (43%) of eligible articles [25, 27, 28], where 22 backs and 16 forwards were included in those studies. This manual process also takes 60 h to complete a single case study [54]. The dynamics of concussive head impacts in rugby and Australian rules football. Studies reported a variety of joint angles including the neck [26,27,28], trunk [26,27,28], hip [25, 28], knee [25, 28], shoulder [27, 28] and ankle [28]. 2020;15(7):e0235035. Some of the key findings across these studies are summarised below. Med Sci Sports Exerc. The authors, Suzi Edwards, Gordon Fuller, Matthew Buchanan, Roger Lee, Timana Tahu, Ross Tucker, and Andrew Gardner, declare that they have no competing interest. The ball carrier displayed a significantly higher head angular acceleration and change in angular velocity but not in linear head acceleration when contact by the tackler was made to their upper trunk, compared to mid/lower trunk tackle [22]. Sports Biomech. Though some eligible studies used a suitable 15 [26] or 16 Hz [22, 23] cutoff frequency, two studies oversmoothed their data with a selection of 6 Hz cutoff frequency [27, 28], a process that causes problems with signal distortion. J Sci Med Sport. Seven studies met the eligibility criteria for inclusion in this review. Considering the importance of measuring head acceleration during a tackle to understand head impacts, if you set a sampling frequency too low, you will miss measuring the true peak head acceleration magnitude due to the aliasing error and thus make the results redundant. The full texts of 35 articles were retrieved and reviewed: 17 articles were identified as using 2D video footage for qualitative analysis; three studies used 2D video footage for qualitative and 2D for quantitative analysis; two articles used in-game 2D video footage for 3D quantitative analysis; one study used 3D equipment other than motion capture; and five articles were either conference abstracts or review articles. 2016;2(1):e000053. Terms and Conditions, Med Sci Sports Exerc. https://doi.org/10.1115/1.3138397. J Sports Sci. The tacklers shoulder height and step distance when tackling a tackle bag were not significantly different for any of the four tackle conditions examined [28]. Playing experience, when reported, ranged from less than 6 months [25] to an average of over 11 years [27]. ISB recommendation on definitions of joint coordinate system of various joints for the reporting of human joint motion-part I: ankle, hip, and spine.