Content uploaded by Cliff Eaton
Author content
All content in this area was uploaded by Cliff Eaton on Dec 16, 2020
Content may be subject to copyright.
A preview of the PDF is not available
Position specific rehabilitation for rugby union players. Part I: Empirical movement analysis data
Abstract
Objectives: The purpose of the study was to quantify the positional movement patterns of professional Rugby Union players competing in the English Premiership. Design: A cross sectional design was used. Setting: Field based data collection of one professional rugby union club during six league matches. Participants: An incidental sample of 35 professional rugby players with an age range of 20-34 years. Method: Recordings of the positional demands, taken from ten image recognition sensors, were coded for the specified high (HI) and low intensity (LI) tasks. Work-to-rest ratios were also calculated. Statistical assessment used an independent groups one-way ANOVA with post-hoc Scheffe test. Results: For all HI and LI activities there were significant position-related differences (P<0.05). In HI activities there were a range of different post-hoc Scheffe outcomes. The Props sprinted 1±1 time during a game while the Outside Backs sprinted 14±5 times. There were fewer post-hoc differences for the LI activities. For example, the Props jogged 325±26 times and the Outside Backs jogged 339±45 times. There was no significant position-related difference in the work-to-rest ratios for the quantity of HI and LI activities (P>0.05). There was, however, a significant positional difference when comparing the work to rest ratio for time spent in HI and LI activities (P<0.05). The Loose Forwards had the least amount of recovery with a work to rest time ratio, in seconds, of 1:7.5 s. The Outside Backs had the most amount of recovery, 1:14.6 s. Conclusions: There were clear positional differences in the quantity and time spent in rugby specific demands. These differences are most obvious in the HI activities of the game and included position-specific differences within both the Forward and Backs units.
... [6][7][8], whereas backs players consist of inside (nos. 9 and 10), midfield (10,11), and outside (9,12,13) backs players. Specifically, the tight-5 are the main drivers of the scrum and are primarily responsible for high-intensity contact actions, including rucks, mauls, and lineouts (8,32). ...
... For example, both loose forwards and half-backs exhibit similar player loads, moderate-to high-speed running distances (3.8-5 m·s 21 :140 vs. 155 m; .5.6 m·s 21 : 112-268 m vs. 177-253 m), and mean (9.1-15.5 m vs. 12.8-19.1 m) and maximum sprint (29.4 vs. 40.2 m) distances, yet loose forwards are required to perform contact actions twice as often (38 vs. 19) with less recovery time (;35 vs. ;80 seconds), highlighting key tactical nuances (12,22). Across the back line, inside backs handle and pass the ball most frequently and have the highest kicking loads (8,32), whereas inside (11 6 4) and midfield (9 6 4) backs typically perform a greater number of tackles than outside backs (6 6 3) (12). ...
... m) distances, yet loose forwards are required to perform contact actions twice as often (38 vs. 19) with less recovery time (;35 vs. ;80 seconds), highlighting key tactical nuances (12,22). Across the back line, inside backs handle and pass the ball most frequently and have the highest kicking loads (8,32), whereas inside (11 6 4) and midfield (9 6 4) backs typically perform a greater number of tackles than outside backs (6 6 3) (12). For sprint performance, midbacks (20 6 6 sprints) and outside backs (20 6 7 sprints) typically complete the greatest number of sprinting bouts (inside backs: 12 6 5 sprints; loose: 10 6 6 sprints; tight: 4 6 3 sprints), whereas outside backs perform the greatest mean (3.84 seconds vs. 2.01-2.53 ...
Watkins, CM, Storey, A, McGuigan, MR, Downes, P, and Gill, ND. Horizontal force-velocity-power profiling of rugby players: A cross-sectional analysis of competition-level and position-specific movement demands. J Strength Cond Res XX(X): 000-000, 2021-Speed and acceleration are crucial to competitive success in all levels of rugby union. However, positional demands affect an athlete's expression of force and velocity during the match. This study investigated maximal sprint performance and horizontal force-velocity (FV) profiles in 176 rugby union players participating in amateur club, professional, and international competitions. Rugby players were divided into 5 positional groups: tight-5 forwards (n = 63), loose forwards (n = 35), inside backs (n = 29), midbacks (n = 22), and outside (n = 27) backs. Sprint performance was averaged across 2 trials of a maximal 30-m sprint, separated by a 3-minute rest. The results demonstrated differences in sprint performance and FV profile characteristics across competitions and positional groups. Specifically, both international and professional players possessed significantly faster split times and superior FV profiles than club players (p < 0.01; effect size [ES]: 0.22-1.42). International players were significantly faster across 0-10 m than professional players (p = 0.03; ES: 0.44-0.47), whereas professional players had faster 10-20 m times (p = 0.03; ES: 0.37-0.41) and a more force-dominant profile (p < 0.01; ES: 0.71-1.00). Across positions, split times decreased and maximal velocity characteristics increased in proportion with increasing positional number, with outside backs being the fastest (ES: 0.38-2.22). On the other hand, both forwards groups had more force-dominant profiles and average sprint momentum across all distances than all backs positions. Interestingly, loose forwards had a more forceful profile and slower 10-, 20-, and 30-m split times but similar maximal velocity characteristics to inside backs, highlighting unique positional demands and physical attributes.
... Rugby union is characterised as a high-intensity, intermittent contact sport, requiring athletes to perform 26 repeated running actions, collisions, and static efforts of differing work-to-rest periods (46). The 27 profiling of the physical characteristics of elite rugby union players has highlighted a number of 28 position-specific attributes (19). Typically, the forwards are the strongest, heaviest, and tallest players 29 in order to be competitive within rucks, mauls, and lineouts (9). ...
... Despite this, Cunningham et al., (2018) identified no 150 relationship between 10 m sprint momentum and ball-carrying capability amongst international rugby 151 union forwards (14). However, 10 m sprint momentum may not be an applicable measure for the 152 forward positions (26) as time-motion analysis has demonstrated that forwards typically perform a 153 greater number of shorter distance sprints during a match in comparison to backs (3), with an average 154 distance per sprint of <10 m (19). Therefore, 5 m sprint momentum may possess greater associations 155 with ball-carrying capability amongst the forwards, a hypothesis that future research should investigate. ...
The effectiveness of offensive ball-carrying has been identified as a key determinant in elite rugby union try-scoring success and subsequent match outcome. Despite this, there is limited research evaluating the physical qualities believed to underpin ball-carrying capability amongst elite rugby union players. The aim of this review was to critically appraise the scientific literature that has investigated the use of physical characteristics to explain ball-carrying capability in elite rugby union. Measures of sprint performance, specifically acceleration, maximum sprinting speed, and sprint momentum have presented weak-to-strong correlations with the number of tries scored, line breaks, tackle breaks, defenders beaten, and dominant collisions recorded amongst international rugby union players. In addition, unilateral and bilateral vertical countermovement jump height, peak power output, and drop jump reactive strength index have each demonstrated meaningful associations with the number of tries scored, line breaks, tackle breaks, and dominant collisions. However, various measures of maximal lower-body strength have presented only trivial correlations with the game statistics associated with ball-carrying capability. These trivial correlations are likely a result of the inconsistent and inaccurate methods used to assess maximal lower-body strength, with methods ranging from a box-squat predicted one-repetition maximum to a maximal isometric mid-thigh pull. Further investigation is required to assess the contribution of maximal lower-body strength, agility, repeated sprint ability, and aerobic capacity to ball-carrying capability in elite rugby union. Such robust, objective data could be used to inform the specificity of physical preparation and maximise the transfer of these physical qualities to on-field performance.
... Rugby is also characterized by different competitive characteristics depending on the position. Forwards (FW; numbers 1-8) are classified into front rows (FR; numbers 1-3), second rows (SR; numbers [4][5], and back rows (BR; numbers 6-8) [5][6][7][8]. FR and SR are also combined as tight five (T5; numbers [1][2][3][4][5], as they are all involved in the activity of gaining or retaining possession of the ball and project similar horizontal forces, especially during scrums [9][10][11][12]. In addition, T5 players are involved in high-intensity and heavy-contact activity during the scrum [13]. ...
Low energy availability (LEA) may persist in rugby players. However, timely assessment of energy balance is important but is difficult. Therefore, a practical index that reflects energy availability (EA) is essential. A total of 19 male college rugby players participated in a 2-week pre-season summer camp. Their blood sample was collected after overnight fast prior to (Pre), in the middle (Middle), and after (Post) the camp. Their physical activity in the first half of the camp was calculated using the additive factor method in the forwards (FW; numbers 1-8) and backs (BK; numbers 9-15). The participants were categorized as tight five (T5; numbers 1-5), back row (BR; numbers 6-8), and BK for analysis. All the participants lost weight during the camp (range: from -5.9% to -0.1%). Energy balance in the first half of the camp was negative. Transferrin saturation (TSAT) and serum iron levels significantly decreased to half, or even less, compared with the Pre levels at week 1 and remained low. The changes in TSAT and serum iron levels exhibited a significant positive correlation with the changes in body weight (R = 0.720; R = 0.627) and with energy intake (R = 0.410; R = 461) in T5. LEA occurs in rugby summer camp but is difficult to assess using weight change. Alternately, TSAT and serum iron levels after overnight fast may be better predictors of LEA.
Wing, C, Hart, NH, Ma'ayah, F, and Nosaka, K. Replicating maximum periods of play in Australian football matches through position-specific drills. J Strength Cond Res XX(X): 000-000, 2022-This study evaluated whether a position-specific drill replicates the running intensities of maximum ball in play (BiP) phases in competitive matches of Australian football (AF). Match data were collected on 32 AF players across 3 seasons (2019, 2020, 2021), with training session data collected from the same players across the 2021 season. Three position-specific training drills were created for defense, offense, and combination (defense and offense combined). Running intensities were compared between maximum BiP periods (e.g., periods with the highest metric per minute) from competitive matches and position-specific training drills, as well as between the 3 position-specific training drills using linear mixed models. The significance level was set at p < 0.05. Measures of distance (offense: 44.4 m·minute-1, defense: 83.5 m·minute-1, combination: 50.4 m·minute-1), high-speed running (offense: 76.7 m·minute-1, defense: 134.6 m·minute-1, combination: 89.6 m·minute-1), very high-speed running (offense: 26.7 m·minute-1, defense: 56.2 m·minute-1, combination: 55.0 m·minute-1), and high-intensity efforts (offense: 2.3 efforts·minute-1, defense: 3.0 efforts·minute-1, combination: 2.8 efforts·minute-1), relative to time were greater (p < 0.001) in all 3 position-specific training drills compared with BiP phases. All measured metrics were significantly (p < 0.001) greater in the defense drill compared with the offense drill, whereas distance, high-speed running, PlayerLoad, and accelerations were significantly (p < 0.001) greater when compared with the combination drill. These demonstrate that position-specific training drills that we created replicated or exceeded the running intensities recorded during matches based on maximum BiP periods. Position-specific training drills seem to be an attractive addition to AF players training regimens because it concurrently provides training for physical and technical actions (e.g., handballs).
Purpose
The aims of the present study were two-fold: (i) to investigate the relationship between physical characteristics and the game statistics associated with ball-carrying capability amongst sub-elite rugby union players, and (ii) to predict the level of change in these physical characteristics required to improve the associated game statistic via regression analysis.
Methods
Thirty-eight senior professional players (forwards, n = 22; backs, n = 16) were assessed for body mass (BM), back squat (BS) single-repetition maximum (1RM) normalised to BM (1RM/BM), 10 m sprint velocity (S10), 10 m sprint momentum (SM10), and the game statistics from 22 games within the 2019/20 RFU Championship season. The relationship between these measures and the predicted level of change in a physical measure required to improve the total number of the associated game statistic by one were assessed by Pearson’s correlation coefficient and simple regression analyses.
Results
In forwards, an ~ 11.5% reduction in BM, an ~ 11.8% improvement in BS 1RM/BM, or an ~ 11.5% increase in S10 was required to improve the game statistics associated with ball-carrying capability. In backs, a ~ 19.3% increase in BM or a ~ 15.6% improvement in SM10 was required.
Conclusions
These findings demonstrate that improvements in lower-body relative strength, acceleration performance, and position-specific alterations in body mass are required to maximise the ball-carrying capability and therefore match outcome of sub-elite rugby union players.
Background
Collisions in rugby union and sevens have a high injury incidence and burden, and are also associated with player and team performance. Understanding the frequency and intensity of these collisions is therefore important for coaches and practitioners to adequately prepare players for competition. The aim of this review is to synthesise the current literature to provide a summary of the collision frequencies and intensities for rugby union and rugby sevens based on video-based analysis and microtechnology.
Methods
A systematic search using key words was done on four different databases from 1 January 1990 to 1 September 2021 (PubMed, Scopus, SPORTDiscus and Web of Science).
Results
Seventy-three studies were included in the final review, with fifty-eight studies focusing on rugby union, while fifteen studies explored rugby sevens. Of the included studies, four focused on training—three in rugby union and one in sevens, two focused on both training and match-play in rugby union and one in rugby sevens, while the remaining sixty-six studies explored collisions from match-play. The studies included, provincial, national, international, professional, experienced, novice and collegiate players. Most of the studies used video-based analysis (n = 37) to quantify collisions. In rugby union, on average a total of 22.0 (19.0–25.0) scrums, 116.2 (62.7–169.7) rucks, and 156.1 (121.2–191.0) tackles occur per match. In sevens, on average 1.8 (1.7–2.0) scrums, 4.8 (0–11.8) rucks and 14.1 (0–32.8) tackles occur per match.
Conclusions
This review showed more studies quantified collisions in matches compared to training. To ensure athletes are adequately prepared for match collision loads, training should be prescribed to meet the match demands. Per minute, rugby sevens players perform more tackles and ball carries into contact than rugby union players and forwards experienced more impacts and tackles than backs. Forwards also perform more very heavy impacts and severe impacts than backs in rugby union. To improve the relationship between matches and training, integrating both video-based analysis and microtechnology is recommended. The frequency and intensity of collisions in training and matches may lead to adaptations for a “collision-fit” player and lend itself to general training principles such as periodisation for optimum collision adaptation.
Trial Registration PROSPERO registration number: CRD42020191112.
Rugby is one of the team sports with the highest incidence rate of injuries per exposure time. These mainly occur in specific sport movements such as the tackle, ruck, or maul. Therefore, it is important to understand the sports’ specificities and biomechanics and link them with its risk and injury type. The most common reported injuries are musculotendinous and ligament ruptures of the lower limbs, however, we highlight the important incidence of severe head and neck injuries, like cerebral concussion and cervical spine fractures. It is essential to gather data that enable us to characterize the risk and specify of each movement performed by the athlete, to make more effective programs on injury-prevention and rehabilitation of injured athletes, always focusing on their full recovery and reinjure risk reduction.
Purpose:
The present study aimed to verify if practicing tackles during rugby union training sessions would affect the players' internal training load and acute strength loss.
Method:
A total of 9 male Italian Serie A rugby union players (age: 21 [2] y) were monitored by means of an integrated approach across 17 sessions, 6 with tackles (WT) and 11 with no tackles (NT). Edwards training load was quantified using heart-rate monitoring. Global positioning system devices were used to quantify the total distance and time at >20 W. Work-to-rest ratio was quantified by means of a video analysis. Before (PRE) and after (POST) the session, the players' well-being and rating of perceived exertion were measured, respectively. The countermovement jump and plyometric push-up jump tests were performed on a force plate to record the players' PRE-POST concentric peak force. Linear mixed models were applied to quantify the differences between WT and NT in terms of training load and PRE-POST force deltas, even controlling for other training factors.
Results:
The Edwards training load (estimated mean [EM]; standard error [SE]; WT: EM = 214, SE = 11.8; NT: EM = 194, SE = 11.1; P = .01) and session rating of perceived exertion (WT: EM = 379, SE = 21.9; NT: EM = 277, SE = 16.4; P < .001) were higher in WT than in NT. Conversely, no difference between the sessions emerged in the countermovement jump and plyometric push-up concentric peak force deltas.
Conclusions:
Although elite rugby union players' external and internal training load can be influenced by practicing tackles, upper- and lower-limb strength seem to not be affected.
A portable self‐powered biosensor big data information processing system has been designed to help coaches monitor athlete training performance in real‐time. The material system is composed of tetrapod‐shaped ZnO nanowires and common textiles. Based on the piezoelectric effect, the device can convert weak shape variables into electrical signals, and the output piezoelectric signal obviously depends on the shape variable, the surrounding humidity and temperature. After attaching the device to the athlete, it can monitor the speed, frequency, angle of an athlete, and surrounding humidity and temperature in real‐time without external power supply. API data collected by information processing end, server behavior simulated by Web service, turns the host of integrated web services into a data server, shares to other terminals via LAN to implement the visual charts summary for data‐driven views, summarize and analyze charts. This multidisciplinary research can point out the new development direction of sport science and may promote the development of flexible self‐powered multifunctional nano‐systems.
Physiological and kinematic data were collected from elite under-19 rugby union players to provide a greater understanding of the physical demands of rugby union. Heart rate, blood lactate and time-motion analysis data were collected from 24 players (mean +/- s(x): body mass 88.7 +/- 9.9 kg, height 185 +/- 7 cm, age 18.4 +/- 0.5 years) during six competitive premiership fixtures. Six players were chosen at random from each of four groups: props and locks, back row forwards, inside backs, outside backs. Heart rate records were classified based on percent time spent in four zones (>95%, 85-95%, 75-84%, <75% HRmax). Blood lactate concentration was measured periodically throughout each match, with movements being classified as standing, walking, jogging, cruising, sprinting, utility, rucking/mauling and scrummaging. The heart rate data indicated that props and locks (58.4%) and back row forwards (56.2%) spent significantly more time in high exertion (85-95% HRmax) than inside backs (40.5%) and outside backs (33.9%) (P < 0.001). Inside backs (36.5%) and outside backs (38.5%) spent significantly more time in moderate exertion (75-84% HRmax) than props and locks (22.6%) and back row forwards (19.8%) (P < 0.05). Outside backs (20.1%) spent significantly more time in low exertion (<75% HRmax) than props and locks (5.8%) and back row forwards (5.6%) (P < 0.05). Mean blood lactate concentration did not differ significantly between groups (range: 4.67 mmol x l(-1) for outside backs to 7.22 mmol x l(-1) for back row forwards; P < 0.05). The motion analysis data indicated that outside backs (5750 m) covered a significantly greater total distance than either props and locks or back row forwards (4400 and 4080 m, respectively; P < 0.05). Inside backs and outside backs covered significantly greater distances walking (1740 and 1780 m, respectively; P < 0.001), in utility movements (417 and 475 m, respectively; P < 0.001) and sprinting (208 and 340 m, respectively; P < 0.001) than either props and locks or back row forwards (walking: 1000 and 991 m; utility movements: 106 and 154 m; sprinting: 72 and 94 m, respectively). Outside backs covered a significantly greater distance sprinting than inside backs (208 and 340 m, respectively; P < 0.001). Forwards maintained a higher level of exertion than backs, due to more constant motion and a large involvement in static high-intensity activities. A mean blood lactate concentration of 4.8-7.2 mmol x l(-1) indicated a need for 'lactate tolerance' training to improve hydrogen ion buffering and facilitate removal following high-intensity efforts. Furthermore, the large distances (4.2-5.6 km) covered during, and intermittent nature of, match-play indicated a need for sound aerobic conditioning in all groups (particularly backs) to minimize fatigue and facilitate recovery between high-intensity efforts.
A methodology to assess work rate in competitive professional football was designed and validated. The technique required monitoring by observation the intensity and extent of discrete activities during match play and was found to have a measurement error of less than one percent. Performance was observed over 51 games. A complete match typically involved approximately nine hundred separate movement activities per player. The overall distance covered per game was observed to be a function of positional role, the greatest distance covered in outfield players being in mid fielders, the least in centre backs.
Rehabilitation of the injured athlete typically follows a pre-determined protocol utilizing clinic-based therapy techniques for the restoration of range of motion, flexibility, muscular strength, and endurance. While these techniques have proven to be successful in returning athletes back to activity, they often do not include exercises and activities related to the athlete's sport. The combination of clinic-based and sport-specific functional techniques will provide an individualized, sport-specific rehabilitation protocol for the athlete. This article serves three purposes for athletic therapists who are involved with the rehabilitation of competitive athletes. First, a discussion of clinic-based rehabilitation explores several areas to consider in the design of a protocol. Next, sport-specific functional exercises, progressions, and assessments are presented. Lastly, a rehabilitation protocol for a soccer forward illustrates the use of sport-specific exercises for his or her return to competitive activity.
The aim of this study was to investigate the physical demands of international rugby union. Five games in the 1989-90 Five Nations Championship were analysed using video-recordings of live television transmissions. When the ball was in open play, the average running pace of players central to the action ranged from 5 to 8 m s-1. This together with scrum, lineout, ruck and maul was classified as high-intensity exercise. The density of work was measured by timing the work:rest ratios (W:RRs) throughout each game. The mean duration of the work periods was 19 s and the most frequent W:RRs were in the range of 1:1 to 1:1.9. On average, a scrum, lineout, ruck or maul occurred every 33 s. The ball was in play for an average of 29 min during a scheduled time of play of 80 min. To complement the time-motion analysis, blood samples were taken from six players throughout a first-class game. The highest measured blood lactate (BLa) concentrations for each individual ranged from 5.8 to 9.8 mM. Running speed, duration, BLa levels, physical confrontation and, most particularly, the density of work as illustrated by the W:RRs indicate that the game places greater demands on anaerobic glycolysis than previously reported. This has implications for the physical conditioning of rugby union players.
Rugby union enjoys worldwide popularity, but there is a lack of comprehensive research into the anthropometric and physiological characteristics of its players and the demands of the game, particularly at the elite level. One of the possible explanations for this is that the sport has previously been primarily concerned with the aspects of skill related to the game, rather than the physical and physiological requirements.
However, with the increased physiological demands being placed on the elite players (using the British Isles as an example), with the recent introduction of professionalism, regional championships, the World Cup and major tours, information about the demands of the game and the assessment of, and methods of improving, the anthropometric and physiological characteristics of its players, are of paramount importance.
Match analysis has indicated that rugby is an interval or intermittent sport and players must be able to perform a large number of intensive efforts of 5 to 15 seconds ‘duration with less than 40 seconds’ recovery between each bout of high intensity activity. These observations, together with the metabolic responses during the game, give some insight into its physiological demands and are a prerequisite in the development and prescription of training programmes by coaches in preparing individual players for competition.
The results from studies reporting the anthropometric and physiological characteristics of rugby union players observed that these individuals had unique anthropometric and physiological attributes which depended on positional role and the playing standard. These have important implications for team selection and highlight the necessity for individualised training programmes and fitness attainment targets.
A comparison of competition work rates in elite club and 'Super 12' rugby
- M U Deutsch
- G A Kearney
- N J Rehrer
Deutsch, M. U., Kearney, G. A., & Rehrer, N. J. (2002). A comparison of competition work rates in elite club and 'Super 12' rugby. In T. Reilly, et al. (Ed.), Science and football IV (pp. 160–166). London: Routledge.
A comparison of competition work rates in elite club and ‘Super 12’ rugby
- Deutsch