Qualities or skills discriminating under 19 rugby players by playing standards: a comparative analysis of elite, sub-elite and non-rugby players using the SCRuM test battery

Research note Open Access Published: 22 August 2019 Qualities or skills discriminating under 19 rugby players by playing standards: a comparative analysis of elite, sub-elite and non-rugby players using the SCRuM test battery M. Chiwaridzo  ORCID: orcid.org/0000-0003-4470-96041, G. D. Ferguson1 & B. C. M. Smits-Engelsman1  BMC Research Notes volume 12, Article number: 536 (2019) | Download Citation Article metrics 151 Accesses Abstract Objective Although schoolboy rugby is growing in popularity and played at different competitive levels in Zimbabwe, the influence of playing standard on qualities or skills of older male adolescent rugby players is unknown. Utilising a cross-sectional design, this study determined anthropometric, physiological characteristics and rugby-specific game skills defining elite under 19 (U19) schoolboy rugby players. Following development and subsequent assessment of test–retest reliability of School Clinical Rugby Measure (SCRuM) test battery, this study compared performance outcomes of elite rugby players (n = 41), sub-elite rugby players (n = 46) and non-rugby athletes (n = 26) to identify qualities or skills discriminating (i) elite from sub-elite and non-rugby players, and concomitantly (ii) sub-elite from non-rugby players. Results 40 m speed test (p < 0.001, ES = 1.78) and 2 kg Medicine Ball Chest Throw test (p < 0.001, ES = 1.69) significantly discriminated elite U19 from sub-elite and non-rugby players. These tests further differentiated sub-elite from non-rugby athletes. Additionally, 1RM back squat (p = 0.009, ES = 0.57), 1RM bench press (p = 0.005, ES = 0.61), repeated high-intensity exercise test (p < 0.001, ES = 0.88) and passing ability test (p < 0.001, ES = 0.99) discriminated elite from sub-elite counterparts. These findings highlight important attributes linked to elite U19 schoolboy rugby in Zimbabwe. However, no significant differences were observed for sum of seven skinfold (p = 0.28), tackling (p = 0.08) and catching ability (p = 0.05). Introduction Lately, research examining characteristics of schoolboy rugby union (RU) players has increased [1,2,3,4]. This has been necessitated by expanding participation rates in a combative sport known for high injury risk and match/training volumes [2, 5,6,7,8,9,10]. Moreover, the reported high physical and technical demands of adolescent RU [1, 5] require junior players to have optimal qualities or technical proficiencies for effective participation. Therefore, research defining key attributes important in competitive schoolboy RU is warranted especially in Zimbabwe where schoolboy RU is emerging and played at different competitive levels [11, 12]. Such evidence has implications on talent identification (TID) and long-term player development [13]. To understand player attributes important in RU, previous studies compared schoolboy RU players by playing standards at U13 [14], U16 [15] and U18 level [13, 16]. For most of these studies [14,15,16], the influence of playing standard was examined by comparing performance outcomes of elite adolescent RU players playing in two countries of different playing abilities. Observed differences between studies reflect differences in lifestyle, socio-economic, environmental, training philosophies, and TID initiatives among other factors. In contrast, Jones et al. [14] compared physical qualities of U18 RU players playing at different standards (academy rugby vs. school rugby) in England. The identified qualities differentiating academy from school-level RU players possibly suggest important variables contributing to a higher playing standard in U18 RU. Given the important influence of increasing age in player characteristic development [17], U19s are an important group to target since they represent a group transitioning into senior professional rugby. To understand the attributes defining good U19 schoolboy rugby players, this study compared anthropometric and physiological characteristics across differing playing standards of elite, sub-elite and non-rugby players, and further compared rugby-specific game skills between elite and sub-elite RU players. It was hypothesised that test performances would improve significantly with increasing playing standards. Main text Study design, setting and participants This study formed part of the School Clinical Rugby Measure (SCRuM) project described elsewhere [11, 12, 18] and was conducted in two sequential parts. Adopting a pragmatic “in-season” approach previously used by Enright et al. [19], the preliminary study established the absolute and relative reliability of each test item in the assembled SCRuM test battery. Forty-one elite U19 schoolboy rugby players completed all tests (Fig. 1) with 7 days separating test–retest assessments. The participants were recruited from one school based in Harare, Zimbabwe playing rugby in the Super Eight Schools Rugby League (SESRL). The SESRL is the most competitive schoolboy rugby league in Zimbabwe [20]. Participant testing commenced in third week from the inception of SESRL season in May 2018 (Additional file 1). Participants with self-reported injuries or any other health-related condition precluding participation in physical activity were excluded. Fig. 1 Flow chart for participants enrolled in the preliminary test–retest reliability study. Parental documents entailed Adolescent Medical Health Questionnaires and Parental Information letters Full size image Utilising a cross-sectional design, the main study compared test performances of three groups of athletes. The study used baseline reliability data for elite players. Sub-elite participants were U19 male adolescent players (n = 46) recruited from a school playing in the Co-educational Schools Rugby League (CESRL). The CESRL represents a second-tier schoolboy rugby league [18]. Also, U19 schoolboy cricket players (n = 21) from one top cricket-playing school represented non-rugby athletes. The cricket players were included as a second comparative group composed of elite athletes playing a sport known to have differing physical and technical demands than rugby [21, 22]. This study was approved by University of Cape Town Human Research Ethics Committee (HREC: 016/2016). Written informed assent and consent were obtained from participants and parents respectively. Procedures All eligible athletes undertook assessments in the SCRuM test battery (Additional file 2). The rationale and processes of assembling the test battery and its subsequent evaluation of face, logical validity and practical feasibility have been described elsewhere [18]. Subsequently, test–retest reliability of each SCRuM test item was established in the preliminary study using elite U19 rugby participants. Before testing, all participants were familiarised to the test battery on 2 consecutive days. Baseline results for these players were compared to data obtained from U19 sub-elite and non-rugby players. (...truncated)