Abstract
Background:
Head-down tackling has been associated with higher rates of head and neck injuries and less successful tackles compared with head-up tackling in American football. In rugby, head and neck injuries have been associated with tackling, with the tackler’s head positioned in front of the ball carrier.
Purpose:
To assess the success and risks of tackling techniques used in the English Rugby Premiership matches.
Study Design:
Cross-sectional study; Level of evidence, 3.
Methods:
Three reviewers analyzed 1000 consecutive solo defensive tackling attempts during the 2022 to 2023 season in 6 English Rugby Premiership matches. Slow-motion replays were used to analyze the success of the tackling attempt in terms of head angulation (head up vs head down), head position relative to the offensive player’s waist at point of contact, and tackling method (inside shoulder, arm, head across the bow, and head-to-head). The chi-square test or Fisher exact test was used to analyze categorical data, and the 2-tailed Student t test or the Mann-Whitney U test was used to analyze continuous data.
Results:
The mean interrater reliabilities for analyzing the tackles were good across all groups (κ = 0.715). Head-up and head-down tackling occurred in 848 tackle attempts (84.8%) and 152 tackle attempts (15.2%), respectively. Head-up tackles were successful in 80.7% of the tackle attempts compared with 71.1% of the head-down tackle attempts (P = .0072). Tackles made at or above the waist were successful in 80.7% of the tackle attempts compared with 73.1% of tackles below the waist (P = .0193). The inside-shoulder technique had the highest successful tackle rate at 90.8%, compared with 44.2% with the arm technique (P < .0001) and 72.4% with the head-across-the-bow technique (P < .0001). The inside-shoulder technique resulted in head-up tackling in 84.8% of players compared with 59.8% with the head-across-the-bow technique (P < .0001) and 94.9% with arm tackling (P = .0001). There were 4 recorded injuries to the tackler: 2 neck injuries, 1 shoulder injury, and 1 wrist/hand injury.
Conclusion:
Head-up tackling, tackles made at or above the level of the offensive player’s waist, and inside-shoulder tackling were found to be more efficient in producing successful tackles. The head-down, tackling below the waist, and head-across-the-bow techniques were associated with poor tackling and lower success rates.
Rugby is one of the largest collision sports in the world. Similar to American football, it is associated with various injuries, including brain and cervical spine injuries. In rugby union, the most common variant played professionally, play is generally continuous throughout the match unless the ball goes out of bounds or an infraction occurs. In contrast, American football is divided into discrete downs, which results in a temporary stoppage of play after the ball carrier is tackled. The continuity of play in rugby resulted in a mean of 156 tackles per match 8 compared with a mean of 122 tackles per game in the National Football League during the 2022 to 2023 season. 11
The game of rugby is extremely physical and has multiple contact events at various speed levels. Rugby players do not wear significant padding or helmets, unlike their American football counterparts, leading to higher rates of injuries of the head, neck, and shoulders than in other sports. 9 Because rugby players are protected only by their tackling technique and positioning at the time of impact, the World Rugby Union recommends the tackler’s head be positioned behind or to 1 side of the ball carrier during tackling. 16 However, despite these recommendations, given the speed and intensity of play, players commonly find themselves delivering tackles with incorrect head positions.
In American football, certain tacking positions, such as spear tackling, have been banned because of their significant association with catastrophic spine injuries. 13 Unsafe tackling techniques (eg, tackling with the head down and across the bow of the ball carrier) have been shown to increase the risk of concussions, cervical spine injuries secondary to axial loading, and brachial plexus neurapraxia while also decreasing tackle success. 10 In contrast, safer tackling techniques (eg, tackling with the head up and making contact with the inside shoulder) have demonstrated higher rates of tackle success in American football. 6
To our knowledge, no prior studies have investigated the incidence or effectiveness of these different tackling techniques in professional rugby union. Thus, the objective of this study was to assess tackling techniques used during rugby union games and analyze the successful tackling rates using these techniques. Additionally, we aimed to identify the incidence of injury in a sample of 1000 rugby tackles.
Methods
Study Population
The study protocol analyzed publicly available data and was thus exempt from institutional review board approval. A retrospective cohort analysis was performed of 1000 consecutive solo defensive tackling attempts made during the 2022 to 2023 season in 6 English Rugby Premiership matches. The analysis was performed in February and March 2022 by 3 reviewers (B.P.M., D.D., and B.D.) who had experience in analyzing tackling methods. Inclusion criteria were any defensive tackle attempts, which were defined by modification of the successful tackle criteria proposed by Coghetto et al 1 : tackler’s feet positioned near the ball carrier; contact initiated by the tackler; trunk and lower limbs tilted toward the ball carrier; contact made with the shoulder, torso, or arms; and arms closing at the moment of the collision. Exclusion criteria were tackles that were unable to be analyzed because of inadequate replays or camera angles.
Data Collection
Slow-motion replays were used to analyze the success of the tackling attempt. Head-up tackling was defined as a head angle >30° relative to the ground, and head-down tackles were defined as angles <30° relative to the ground. Other tackling variables of interest included head position relative to the offensive player’s waist at point of contact (at or above the waist or below the waist) during the tackling attempt, as well as tackling method: head-across-the-bow of the ball carrier (Figure 1A); head-to-head, inside-shoulder (Figure 1B); or arm (Figure 1C) tackle. A modified version of a previously described method for analyzing American football tackles by our author group 6 was used for tackle analysis (Appendix Table A1). 15 Any injuries associated with the tackle were also obtained. Each of the 3 reviewers analyzed the same 1000 tackles across 6 matches (mean, 166.7 ± 71.2 tackles per match), and each was blinded from the other 2 reviewers to accurately assess the interrater reliabilities.
Tackling methods analyzed in this study. (A) Head across the bow. (B) Inside shoulder. (C) Arm tackle.
Statistical Analysis
Data analysis was performed using the Statistical Package for the Social Sciences (SPSS) statistical software (Version 25.0; IBM). The chi-square test or Fisher exact test was used to analyze categorical variables, and the 2-tailed Student t test or the Mann-Whitney U test was used to analyze continuous variables. P <.05 was considered statistically significant.
The interrater reliability of the reviewers’ tackling assessments was analyzed using the kappa statistic, with κ values interpreted according to Landis and Koch 7 as follows: ≤0.2 implies poor agreement; >0.21 to 0.4, fair agreement; >0.41 to 0.6, moderate agreement; >0.61 to 0.8, good agreement; and >0.81 to 1.0, very good agreement.
Results
The mean interrater reliabilities were good across all groups (κ = 0.715; range, 0.542-0.894) (Table 1). Head-up and head-down tackling occurred in 848 tackle attempts (84.8%) and 152 tackle attempts (15.2%), respectively (Table 2). Head-up tackles were successful in 80.7% of the tackle attempts compared with 71.1% of the head-down tackle attempts (P = .0072). Tackles were made at or above the level of the offensive player’s waist in 807 tackle attempts (80.7%) and below the waist in 193 tackle attempts (19.3%). Tackles at or above the waist were successful in 80.7% of the tackle attempts compared with 73.1% of tackles below the waist (P = .0193).
Interrater Reliability for Raters A, B, and C a
Interpretation of κ: ≤0.2, poor; >0.21 to 0.4, fair; >0.41 to 0.6, moderate; >0.61 to 0.8, good; >0.81 to 1, very good agreement.
Summary of Tackles According to Head-Up and Head-Down Tackles a
Data are reported as n (%).
There were 698 tackles using the inside-shoulder technique (69.8%), 215 with the arm technique (21.5%), and 87 with the head-across-the-bow technique (8.7%) (Table 3). No tackles using the head-to-head technique were reported. The inside-shoulder technique had the highest successful tackle rate of 90.8%, compared with 44.2% with the arm technique (P < .0001) and 72.4% with the head-across-the-bow technique (P < .0001) (Figure 2). The inside-shoulder technique resulted in head-up tackling in 84.8% of players compared with 59.8% with the head-across-the-bow technique (P < .0001) and 94.9% with arm tackling (P = .0001) (Figure 3, Table 4). There were 4 recorded injuries to the tackler in this cohort: 2 neck injuries, 1 shoulder injury, and 1 wrist/hand injury. Therefore, the incidence of injury to tacklers in this cohort was 4 injuries per 1000 tackles.
Tackle Success by Tackle Method a
Data are reported as n (% of tackles for that method).
Tackle success percentage by tackle method. **P < .001.
Head-up tackle percentage by tackle method. **P < .001.
Tackle Success by Tackle Method and Relationship to Offensive Player’s Waist a
Dashes indicate areas not applicable. ATB, across the bow; IS, inside shoulder.
Rates are presented as the number of tackles divided by the total tackle attempts for each tackle method.
Discussion
The results of this study indicated that head-up tackles were successful in 80.7% of the tackle attempts in contrast to head-down tackles, which were successful in 71.1% of tackle attempts (P = .0072). This was similar to findings from prior studies in American football by Stockwell et al 10 and our author group 6 indicating that head-up tackles are associated with higher success rates than head-down tackles. Moreover, in the current study, tackles made at or above the waist were successful in 80.7% of the tackle attempts compared with 73.1% of tackles below the waist (P = .0193). Similarly, in our previous study on American football, 6 tackles made at or above the waist were successful in 81.2% of the tackle attempts compared with 67.2% of tackles below the waist (P < .001). Our current analysis also found that, as with previous findings, 6 executing a head-up technique will naturally raise the point of contact with the ball carrier to deliver a tackle at or above the level of the waist. This demonstrates that there is a strong resemblance in successful tackling methods between American football and rugby.
Within our analysis, the inside-shoulder technique was more commonly seen (70%) than the arm technique (22%), and no head-to-head impacts were identified. A prospective study of 645 rugby union players by Fuller et al 4 found a 55% incidence of the arm technique and a 22.5% incidence of the inside-shoulder technique with no reports of direct head-to-head or spear tackles. We found that using the head-across-the-bow technique (35/87 [40%] tackles) was associated with significantly higher rates of head-down tackling compared with the inside-shoulder technique (106/592 [18%] tackles; P < .001). Tackling using the head-down position and the head-across-the-bow technique places the head and neck in a position at high risk for injury. 5 A retrospective study of 156 rugby union players by Davidow et al 2 showed that the head-up tackling technique using the inside shoulder or arm had a higher success rate and lower incidence of neck injuries than head-down positioning. These findings further demonstrate the importance of maintaining a head-up technique during tackling, which naturally avoids high-risk positions during impact.
In our study, the inside-shoulder technique had the highest successful tackle rate of 91%, followed by the head-across-the-bow (72%) and arm (44%) techniques. A retrospective study of 2092 rugby union tackles by Hendricks et al 5 showed significantly reduced tackle success with arm, jersey, and collision-based tackles compared with shoulder tackles. Another retrospective study of 25 subelite rugby union players by Coghetto et al 1 reported that proper techniques were better associated with successful tackles, rucks, and carries rather than physical qualities of players. These findings all emphasize the importance of teaching and learning safe and effective rugby tackling technique. Based on literature demonstrating that tackling in an upright position above the level of the ball carrier’s torso increases the risk of head injury,12,14 the Rugby Football Union voted in April 2023 to adopt law changes to lower the legal tackle height to below the base of the sternum. 3 Additional evidence has shown that tackling with the head in front of the ball carrier increases the risk of concussions, neck injuries, and stingers compared with tackles with the head position behind or to the side of the ball carrier. 9 In conjunction with these findings, the results of the present study indicated that tackling with the waist bent, the head up and behind the ball carrier (ie, inside shoulder), and contacting the ball carrier at the level of the upper trunk is the safest and most effective tackling technique in rugby.
Finally, we found that the mean interrater reliability across all groups was good (κ = 0.715). This was similar to our previous study in collegiate American football players, 6 in which the mean interrater reliability across all groups was 0.718. In addition, the method of tackle grading within the current study and our previous study was similar, modified only slightly based on the difference in sport (Appendix Table A1). These likenesses between the studies again demonstrate the resemblances in tackling methods between the 2 sports.
Limitations and Strengths
There are several limitations to this study. First, because of the retrospective nature of this study, data analysis may be prone to selection bias. This study clearly demonstrated the association between the head-up, inside-shoulder technique and tackle success rate, but the inherent correlation between certain tackle techniques, head positioning, and tackle success cannot be ignored. Although head-up, inside-shoulder tackling was shown to result in more successful tackles compared with alternative techniques, the execution of a head-up, inside-shoulder tackle necessitates that the tackler is in a good position relative to the ball carrier before the tackle is initiated. In contrast, players who initiate a tackler in a poor position relative to the ball carrier are prone to using less effective tackling techniques (eg, head-down and arm tackles), not necessarily as a matter of choice, but because their poor position relative to the ball carrier makes these tackling techniques the most viable option for making contact with the ball carrier. Therefore, a limitation of this study is its inability to eliminate how the implicit association between tackler position before initiation of the tackle and the corresponding tackling technique performed ultimately affect tackle success rates. This study also used publicly available game footage used for general game review and not for quantitatively grading tackling techniques. Finally, this study was not designed to identify direct correlations between tackling techniques and injury incidence, which has been performed in prior studies.
Despite these limitations, to our knowledge, this is the largest study analyzing the tackling techniques used during English Rugby Premiership matches and their relation to successful tackles. The strength of this study was the ability to identify the clear association of the head-down technique with poorer tackling methods and lower tackling success. Although this study presented the incidence of injury to tacklers in a sample of 1000 professional rugby tackles, the incidence of injuries sustained by tacklers relative to specific tackling techniques was not described. However, the study findings showed a significant association between decreased tackle success and tackling techniques that have previously been shown to increase the incidence of head and neck injuries. 5 Therefore, the results of this study allow both the sports physicians and athletic trainers who are in direct contact with these players to convey not only the risk of these poorer tackling methods but also their inefficiency in producing successful tackles. Future studies that focus on investigating the injury rate on a per-tackle basis as well as correlating the tackling technique statistics with techniques taught by coaches among English Rugby Premiership teams would be helpful to better assess the safety ramifications of these techniques.
Conclusion
The head-up tackling technique, tackles made at or above the level of the offensive player’s waist, and the inside-shoulder technique were found to be more efficient in producing successful tackles. The head-down, tackling below the waist, and head-across-the-bow techniques were associated with poor tackling and lower success rates.
Footnotes
Appendix
Tackling Terms and Grading a
| Tackle methods |
| • Head across the bow: During initial impact, the head of the defender is across the path of the runner’s momentum. |
| Technique: https://www.youtube.com/watch?v=LtvgqmnsgG8 |
| Example: https://www.youtube.com/shorts/oUx11fdiobw |
| • Head-to-head: Any time the initial contact made is head-to-head; usurps other tackle categories. This is an illegal tackling move in rugby and is considered a dangerous tackle in the World Rugby laws. 15 Tacklers are subject to potential sanctions, ranging from a penalty to a yellow card to a red card. |
| • Inside shoulder: Initial contact made by the defender with the shoulder; the aim is at the offensive player’s near shoulder, and the defender’s head remains to the inside of that shoulder, not crossing in front of the runner’s body and momentum. |
| Technique: https://www.youtube.com/watch?v=mMHRZ8LzS7Q |
| Example: https://www.youtube.com/shorts/srXQe1J7Lus |
| • Arm: Initial and substantial defensive player contact with the runner is with outstretched arm(s), not with shoulder or head. Tackle attempts where the defensive player lunged for but missed the offensive player were categorized as arm tackles by default. |
| Example: https://www.youtube.com/shorts/QZCGbNFP1c4 |
| Rating of head position |
| • Head up: Head approximately >30° to the ground during the initial contact. |
| • Head down: Head approximately <30° to the ground during initial contact. |
| Relationship of defensive player to the waist |
| • Above: The tackler’s initial point of contact is above the offensive player’s waist/belt line. |
| • At: The tackler’s initial point of contact is at the offensive player’s waist/belt line. |
| • Below: The tackler’s initial point of contact is below the offensive player’s waist/belt line. Missed tackle attempts where the defensive player did not touch the offensive player were counted as below by default. |
| Tackle success |
| • Successful: The defender successfully stops the ball carrier from advancing by taking them to the ground, causing them to release the ball. More than 1 player can be credited with a successful tackle attempt at the same time. In such a situation, the initial defender must maintain contact while another defender(s) completes the tackle. |
| • Unsuccessful: The defensive player makes a defensive move toward the ball carrier and misses the player or does not successfully take the player to the ground. If the defender has contact with the runner but the runner breaks free and remains inside the touchline to continue play, this is an unsuccessful tackle. |
Adapted from Hirase et al. 6
Final revision submitted October 18, 2023; accepted December 5, 2023.
One or more of the authors has declared the following potential conflict of interest or source of funding: R.A.W.M. has received grant support from NuVasive, education payments from Cerapedics, consulting fees from DePuy Synthes/Medical Device Business Services and Stryker, and royalties from Globus Medical. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.
Ethical approval was not sought for the present study.