RETURN TO PLAY PROGRESSION FOR RUGBY FOLLOWING INJURY TO THE LOWER EXTREMITY: A CLINICAL COMMENTARY AND REVIEW OF THE LITERATURE

Abstract

Background & Purpose

Rugby requires unique demands from its players. Those involved in rehabilitation and care of these athletes must possess an understanding of both the game and various positions. There have been numerous reports focusing on the physiological demands and biomechanical analyses of various components of gameplay, but no specific progression has been developed to assist clinicians assessing the readiness to return of a player after injury. The purpose of this clinical commentary is to outline testing components, general gameplay guidelines, movement progressions, and sport and position-specific progressions related to rugby gameplay following a lower extremity injury.

Description of Topic

This commentary provides a recommended progression for clinical use for use in a return to rugby program. It includes metabolic considerations, advanced strengthening exercises, agility exercises, and incorporation of drills specific to the sport of rugby that may be performed with the clinician or with assistance from team members. This progression also includes testing parameters for each phase and guidance for clinicians regarding the ability to gauge readiness to return to sport.

Discussion

It is essential that an athlete returning to the sport of rugby undertake a guided, graduated return to sport progression to ensure safety and to decrease the risk of re-injury. This proposed return to sport progression outlines key parameters for both the sport as a whole and for various specific positions.

Level of Evidence

Level 5 – Clinical Commentary, Review of Literature

INTRODUCTION

Clinicians involved in the care of rugby players must not only be aware of the underlying pathology of the injured site, but also the specific physiological demands required for successful play in this sport. In addition, the various positions in the game of rugby each necessitate a unique skill set and metabolic requirement for effective performance in the domains of speed, agility, power, and endurance. Returning an athlete to sport requires a multidisciplinary approach, often involving surgeons, other physicians, physical therapists, athletic trainers, strength and performance coaches, nutritionists, and psychologists. As a rehabilitation specialist, knowledge of each rugby position is essential in order to fully prepare the player for successful reintegration into competition.

Time missed from match or training due to injury has been reported to range from two hours¹ to over 262 hours per 1000 player hours.² The lower extremity is the most common site of injury, with 41% to 55% of all injuries in rugby sustained in the lower extremity.³ Medial collateral ligament (MCL) and anterior cruciate ligament (ACL) injuries have been reported to result in the greatest proportion of absence from play.⁴ Lateral ankle sprains are the most common injury occurring at the ankle joint.^5,6 Noncontact injuries account for 57% of those sustained during training,⁶ although this proportion decreases during match play.⁵ Noncontact injuries of the knee have been reported to be as high as 22% of all match related injuries.⁴ Hamstring muscle injuries account for the highest number of noncontact injuries overall.^5,6

The purpose of this clinical commentary is to outline testing components, general gameplay guidelines, movement progressions, and sport and position-specific progressions related to rugby gameplay following an injury to the lower extremity.

GENERAL GAMEPLAY

The sport of rugby is played with 15 members per team (8 forwards and 7 backs) on a 100 meter by 70 meter field with two try zones at either end that are 10 meters deep. A typical match duration is 80 minutes total with two 40 minute halves, as well as additional stoppage time as needed. Players may run in any direction as long as they do not use another player to block for them, which results in an infringement called obstruction.

Although the game clock is designed for continuous play, the sport of rugby is played primarily in bursts of varying duration that depends upon an assortment of factors, such as a player's position and role in the game. Elite players reach peak speeds of 13.1-19.3 miles•hour⁻¹ with the total distance covered by players in a match ranging from 3.9-4.5 miles.⁴⁴ On average, players compete at a mean of 80-85% of their VO₂ maximum and at approximately 88% of their maximal heart rate.⁴⁴

In general, backs cover greater total distances than forwards.⁴⁴ However, flankers devote the most time of the forwards in the high and maximal intensity speed zones.⁴⁴ Forwards sprint an average distance of 8.0 meters for an average duration of 1.1 seconds while backs sprint an average distance of 13.8 meters for an average duration of 1.8 seconds.⁴⁵ Just as the sprint distances and durations vary, the metabolic demands between backs and forwards also differ. Due to their involvement in rucks, mauls, and scrums, forwards require an increased aerobic capacity to continue play following these events, even at a reduced pace. In contrast, backs perform in a more anaerobic environment as they alternate between bursts of speed followed by walking between various stops in play. Therefore, the work-to-rest ratio commonly used in training is typically 1:7 for forwards and 1:20 for backs.⁴⁶

REQUIREMENTS FOR RETURN TO RUGBY

After sustaining an injury to the lower extremity, the athlete progresses through the stages of healing and various fundamentals must be in place prior to examination for and consideration of return to sport. It is assumed that the athlete will demonstrate adequate progression in proper healing parameters, range of motion, and muscular strength as listed in Table 1 prior to progressing to any type of return to sport progression. Unilateral balance and strength training are usually addressed as early as possible to ensure movement normalization. Strength training may then be progressed to circuit training in order to promote a capacity for power endurance using a variety of training modalities, such as Olympic weightlifting, traditional weight training, and other ancillary exercises. Neuromuscular compensations and deficits often persist following any lower extremity injury and typically require guided correction.^7,8 Normalization of these deficits assists in decreasing the risk of a subsequent injury and the movement strategies obtained during this phase serve as the basis for progression through the later phases of rehabilitation.^9,10

Table 1.

Criteria for Initiation of Rugby Progression

Absence of swelling or joint effusion
Full, pain-free PROM and AROM symmetrical to contralateral extremity
Adequate baseline extremity and core strength  ≥ 4/5 strength of affected area via MMT or HHD Appropriate functional tests (select those applicable to appropriate area) 1 minute 8 inch box heel tap comparison 1 minute 8 inch box step up comparison 1 minute calf raise comparison The injured lower extremity should be within 85% of the uninvolved limb

Key: PROM = passive range of motion; AROM = active range of motion; MMT = manual muscle testing; HHD = hand held dynamometry

Pain frequently contributes to diminished strength and coordination output following an initial injury, which necessitates emphasis on neuromuscular control and strength during the initial phases of rehabilitation.^11,12 Once the athlete has begun to develop sufficient strength, he or she may then begin to practice loading, landing, and deceleration mechanics. Neuromuscular control with these movement strategies are promoted using drills such as lunges, single limb squats, small bounding hops in the sagittal plane progressing to the frontal plane, and drop box landings. Verbal and visual feedback is vital to assist with the athlete's success, and these cues have been proven to alter an athlete's movement strategy.^10,13,14 An anti-gravity treadmill or aquatic environment may assist in unloading the athlete's weight while respecting physiological healing and decreasing the overall demand placed on the lower extremities.

Prior to the return to sport progression, a progressive running tolerance program on level surfaces should be initiated when appropriate. As the athlete begins to demonstrate improved strength and appropriate neuromuscular control, he or she may initiate more advanced strength training. These may include, but are not limited to, Olympic weightlifting derivatives, such as squats, deadlifts, power cleans, and Romanian deadlifts. It is also important to include triple extension strength, and power development, utilizing bungee cords or cables for increased time under tension.

The authors’ recommended testing elements for demonstration of movement normalization are contained in Table 2. The Y-Balance Test™ is a measurement of single limb balance and motor control, that has been validated in the literature, most notably with regards to injury risk assessment.^15-17 The authors recommend the use of this test to ensure the returning athlete demonstrate the requisite single limb stability of at least 90% when compared to the contralateral lower extremity. The single leg bridge and single leg squat are other excellent assessments for core stability and appropriate gluteal musculature function and strength. Weakness in the core and hip muscle groups have been identified as risk factors for lower extremity injury risk.^18-21 Altered lower extremity mechanics^18,22 due to the effects of proximal lower extremity muscle weakness have been significantly correlated with lower extremity pathologies such as iliotibial band syndrome,²³ patellofemoral pain syndrome,^24-26 and ankle sprains.²⁷ In order to identify gluteal muscle activation deficits, a single leg bridge can be a useful assessment. During a single leg bridge, the athlete often demonstrates a functional gluteal deficit with overcompensation from the hamstring muscle group. In addition, trunk rotation or a contralateral pelvic drop during a single leg bridge can assist with identification of deficits in core stability. The single leg squat has been proven to identify core strength^26,28 and has been correlated with landing, running, and cutting tasks.^29-32 Athletes often demonstrate increased trunk displacement, contralateral pelvic drop, hip adduction, and valgus collapse^26,33-38 during this maneuver, which are indicative of deficits in postural stability and proximal hip muscle function.^26,39-42 In addition, the single leg squat test has been utilized to screen for residual deficits in core stability and hip abduction strength in baseball players returning from shoulder injury.^40,43

Table 2.

Testing Elements for Demonstration of Movement Normalization

Y-Balance Test™ ≤90% difference between the contralateral lower extremity for each movement

5 single leg bridges with a 10 second isometric hold performed at the top of the movement No presence of trunk rotation or hamstring substitution

1 minute single leg squats to depth of 40-60 ° of knee flexion No presence of valgus collapse Appropriate posterior chain recruitment Sufficient trunk control and balance

Running tolerance Able to run > 20 minutes without symptom provocation or effusion

As the athlete continues to develop strength and power capacity, a progressive plyometric-based program should be incorporated. It is imperative that the athlete demonstrate appropriate eccentric control with landing or deceleration during various drills throughout treatment sessions. It has been well documented that lower extremity biomechanics and movement alterations have been correlated to injuries to the ACL.^47-56 In a study analyzing biomechanical measures during landing, Paterno et al⁹ determined four factors that predispose an athlete to a second ACL injury in those who had previously undergone an ACL reconstruction. These predictive factors included increased knee valgus, asymmetry in knee extensor moment during initial contact, poor single limb postural stability, and decreased contralateral hip rotation strength (assessed using moment data). Clinicians should monitor players for these elements when performing plyometric interventions during rehabilitation. Plyometric activities have been shown to improve sprinting⁵⁷ and agility⁵⁸ performance. Vertical progressions should include depth jumps progressing to tuck jumps (adding rotation when appropriate) and box jumps of varying heights, with the athlete eventually progressing to single limb drills. Horizontal progressions should include line hops, slide board exercises, alternating single limb bounding, as well as single limb single and triple hops crossing over through multiple planes. During these horizontal progressions, the emphasis should be on achieving horizontal rather than vertical displacement in preparation for change of direction and agility drills.⁵⁹

Change of direction and agility are important facets of rugby in order to evade tacklers and create an open field of play.⁵⁹ An athlete's agility performance is strongly influenced by the ability to rapidly decelerate and reaccelerate while adjusting his or her momentum to either pursue or elude opponents.⁶⁰ Team sport athletes are typically involved in change of direction events during sprints of approximately five meters.⁶¹ More specifically, Meir et al⁶² reported that rugby players typically come into contact with an opposing player at distances of 10 meters. Therefore, Delaney et al⁶³ utilized the 505 test⁶⁴ to analyze the contributing factors to change of direction ability of male professional rugby players. The authors concluded that the 505 test performed on the athletes’ dominant lower extremity was significantly correlated with the athletes’ linear sprint speed over a 40 meter distance. Performance of the 505 test on the non-dominant lower extremity was dependent upon relative strength and relative power (determined by a ratio of the player's three repetition maximum back squat and a 40 kilogram barbell squat jump, respectively, divided by the player's body mass). Other researchers who have analyzed change of direction and ability in rugby players have utilized tests involving thirty to forty-five degree cuts,^59,65,66 which have been studied previously in observance with game situations.^60,67-73

During change of direction maneuvers, an athlete uses their plant leg to decelerate his or her body from linear running prior to initiating the change of direction task. The athlete's push off leg then initiates acceleration of the body into the new desired direction.⁵⁹ In a comparison of cutting technique performance of semiprofessional rugby players, Green et al⁵⁹ calculated an average transition time from initial contact of the plant leg to toe off of the push off leg to be significantly shorter in starters versus nonstarters. McLean et al⁶⁸ investigated the biomechanics of sidestep cutting using three-dimensional motion and ground reaction force analysis. After initial contact, anterior and inferior forces of the trunk produces average hip and knee flexion angles of 48.7 and 60.2 degrees, respectively, as well as an average knee valgus angle of 13.2 degrees. These measurements are similar to those calculations previously reported in the literature.^69-71 During the addition of a simulated defensive opponent, athletes demonstrated an increase in hip flexion, knee flexion, and knee valgus angles.⁶⁸

It is imperative that the athlete demonstrates proper technique during agility drills, such as planting with the outside leg, appropriate amount of knee flexion as mentioned previously, leaning into the cut, and full triple extension of the push off leg. Previous authors have reported that a more upright position with increased hip and knee extension at initial contact may correlate to an increased risk of lower extremity injury and may also hinder the athlete's proficiency in generating force to improve the resultant stride velocity after the change of direction task.^68,74 The rehabilitating player should also begin to integrate movements that focus on footwork skill, such as agility ladder drills. As the athlete's footwork begins to return to normal, he or she may then progress to more challenging agility movements, such as the T drill⁷⁵, box drills, and reactive linear and diagonal drills. A progression from proactive to reactive drills should be utilized as the intention of this progression is to prepare the athlete for reintegration into practice activities and noncontact drills with the team. Various testing elements are also useful to aid the clinician's decision to reintegrate the athlete back to practice, such as hop testing,⁷⁶ 40 meter sprints from the upright, prone, and rolling positions, as well as the L run⁷⁷ and the Pro Agility Test.⁷⁷

Once the athlete demonstrates the requisite requirements in preparation for returning to the practice field, he or she should begin a series of rugby-specific practice drills. To the authors’ knowledge, there is no available evidence for the following drill progression and the following are the authors’ recommendations based off similar research published for athletes of similar sports^78,79 that have been adapted for the sport of rugby. These drills are commonly performed in conjunction with the coaching staff while the rehabilitation specialist monitors the returning athlete for any symptom provocation, abnormal movement patterns, performance decline, and psychological factors. Controlled movements with a teammate should be performed initially, such as forward runs with lateral passes within a fixed distance interval (typically 10 meters) followed by diagonal runs and switch passes. The athlete should focus on completing accurate passes rather than maximal effort. During the sport of rugby, passes may be completed directly horizontally or behind the passing player. Once this is effectively demonstrated, the athlete may progress to reactive agility drills beginning with the recovering athlete emulating the movements and changes in the direction of a teammate within a boxed area. The athlete should begin with linear movements before progressing to diagonal and multi-planar movements. Once competence is demonstrated with reactive agility maneuvers, the clinician may then allow scrimmage situations beginning with small-sided games of touch rugby. Reintegration into competitive match play should be accomplished in small increments. Again, the athlete should be monitored for any symptom provocation, abnormal movement patterns, performance decline, and psychological factors. Progressions for other specific aspects of game play, such as lineouts, kicking, scrummaging, and tackling are covered in the next section of this commentary.

POSITION SPECIFIC PROGRESSIONS

Lineout Progression

The purpose of a lineout is to restart game play quickly, safely, and fairly after the ball has left the field of play. The lineout involves a throw-in of the rugby ball between two lines of players (one line from each team) spaced at one meter apart, usually at the exact place where the ball went out of play. The throw in a lineout is usually between 5 and 15 meters in distance⁸⁰ and is normally executed overhead with two hands (with or without a step forward) with the ball being spun about its longitudinal axis (Figures 1a and 1b).⁸⁰

Figure 1.

Lineout sequence, a) Two lines of players from each team are evenly spaced with the thrower preparing to execute an overhead throw, b) Jumpers are hoisted by their teammates in preparation to catch the ball as it is thrown directly down the center of the two lines.

The jumpers (locks) are typically hoisted by one or two lifters (props; typically the strongest members of the team) in order for the jumper to intercept the ball at a height of 3 to 3.5 meters.^45,80,81 Initially, the weight of the jumper is usually shared equally during the lift, but then is transferred toward the rear lifter. Once the ball is caught, the lifter releases his or her teammate resulting in a landing, for the jumper, from a height of 1 to 1.5 meters.⁸¹ Each of the different positions in a lineout requires very different demands and varied stresses placed on the player's body, requiring special attention during the middle and end phases of rehabilitation as the player prepares to return to game play.

Specific requirements for lineout drills will vary for lifters or props, jumpers (locks), and throwers (usually the hooker). For lifters or props, it is essential that they have full shoulder and elbow range of motion and strength. They must demonstrate the requisite core strength and control required to produce enough power to lift jumpers from the ground to a height of 1 to 1.5 meters.^45,80,81 Jumpers (locks) must demonstrate excellent core strength and stability in an upright position, especially on unstable surfaces. They must also demonstrate the ability to safely land from a height of one meter with safe and quick transitions upon landing.^45,80,81 Throwers must have full shoulder mobility and must demonstrate adequate core strength in order to produce power when throwing overhead. They also must demonstrate the ability to accurately throw the rugby ball to the jumper between 5 and 18 meters away.⁸⁰ Specifically, the thrower must demonstrate adequate shoulder flexion, medial rotation, elbow flexion and supination, followed quickly by shoulder extension, lateral rotation, elbow extension, and pronation during the completion of the throw.^80,81 This motion demands full glenohumeral and scapulothoracic motion, as well as adequate thoracic spine mobility, specifically thoracic extension.

Lineout Drills

Lifters: In order to adequately prepare lifters for the demands of a lineout, proper progression of strength and conditioning must be employed with a specific focus on power and triple extension drills. This can be accomplished via kettle bell swings and high-load lower extremity lifts including squats, deadlifts, snatches, cleans, and clean and jerk exercises. A useful drill for these players utilizes a tackle bag to mimic the weight and size of the jumper, ideally with the majority of weight at the top of the object being lifted.⁸¹

Jumpers: Jumpers have multiple roles in a lineout and will have different sport requirements that need to be addressed in the clinic prior to returning to full gameplay. In order to prepare jumpers for the landing aspect of a lineout, drills involving progressive drop jumps up to 1.5 meters high must be performed with good lumbopelvic, knee, and ankle control.⁸¹ These drills should also address landing on unstable surfaces and should incorporate quick transitions, such as landing followed by cutting or sprinting immediately afterwards. Lastly, the drills should incorporate catching or deflecting the rugby ball followed by a safe landing from a height of 1.5 meters.⁸¹ Catching progressions should begin with chest level drills and then progress towards overhead catches and deflections. These drills should initially be performed on stable surfaces before transitioning to unstable surfaces in order to challenge core stability in a similar fashion to catching and/or deflecting the ball while being lifted. Drills should be progressed from proactive drills with a known pattern (such as ball toss to a rebounder) to reactive drills, which involve unknown patterns (such as perturbation training while catching and clinician throwing the ball in different positions and locations to stress reaction to stimulus).⁸² Core stability is another major focus during rehabilitation for preparation of a jumper in their return to safely performing lineouts. These drills should begin in the sagittal plane before incorporating exercises in the transverse plane. Drills should also include quick transitions from catching to throwing with arms overhead, beginning with stable and progressing towards increasingly unstable positions and surfaces. A typical progression of positions includes kneeling to half kneeling, then to standing, and finally to single leg stance.

Throwers: Players that may be placed in the throwing position for a lineout must demonstrate safe and effective lower extremity mechanics during a progressive throwing program. Throwing drills should start with chest passes then progress to overhead passes. Throwing should start with short distances and progress up to at least 18 meters. Target training should be incorporated to promote accuracy and proprioception. This can be accomplished with use of a target that is held at the approximate height of a jumper (approximately 3 to 3.5 meters high).⁸¹ A small medicine ball or weighted rugby ball can also be used for target training to gradually increase demands in a safe environment prior to implementing on-field drills.⁸¹

Section testing elements for return to lineouts include the ability to perform all position-specific lineout requirements as detailed above. Tolerance to intensity should be evaluated by maximal effort in the clinic with drills that closely simulate the position played without symptom provocation, as well as full game play without symptom provocation.

KICKING PROGRESSION

Despite its fundamental role in the game of rugby, frequency and demands of kicking in the sport of rugby are poorly documented.⁸¹ Kicking is an essential skill for backs and must be addressed before the player is fully released to play.⁸¹ In the game of rugby, kicking (Figures 2a and 2b) can be performed out of hand, from a kicking tee (i.e. goal kick or place kick), or from the ground (i.e. drop goal).⁸³ The goal or place kick can be performed toe end style (player approaches the ball straight on and kicks the ball using the toe of the boot) or instep style (player approaches the ball from an angle and kicks the ball with his/her instep). Game play begins with a kick off, either a place kick or a drop kick, from the center of the halfway line. The ball must travel at least 10 meters from the point of kickoff.⁸³ A drop kick from the halfway line will also restart the game after a penalty or drop goal has been scored.⁸³

Figure 2.

Kicking, a) Kick performed from a tee, performed after a try or penalty, b) Drop kick performed using an instep style.

Players who are expected to perform goal kicks or place kicks must be able to demonstrate a long-lasting oscillation with hip extension and maximum knee flexion during the backswing, followed by hip flexion with knee extension.⁸⁴ Specific joint requirements for the kicking leg include at least 100 ° of knee flexion and 10 °-15 ° of hip extension during the backswing, followed by 50 ° of hip flexion and 60 ° of knee flexion at ball impact.⁸⁴ The player must also be able to demonstrate a rigid foot with full ankle plantarflexion and toe flexion at ball contact. The forward swing demands at least 120 ° of hip flexion with 20 ° of knee flexion and the player must demonstrate adequate hamstring length and eccentric hamstring strength to avoid injury with high kicks.⁸⁴ For the non-kicking leg, adequate single leg balance and proprioception are essential for safe performance of kicking requirements during game play. Control and accuracy must be stressed with all kicking drills, and the player must demonstrate adequate hamstring length and eccentric hamstring strength to avoid injury with high kicks.

Kicking drills should begin with short distances with a focus on control and kicking mechanics, and gradually progress to longer distances with greater velocity.⁷⁸ Players should start by holding the ball in their hands and performing drop kicks at short distances into netting in the clinic. Once they have mastered this skill without pain or difficulty, they can progress to goal or place kicks with a tee. Prior to performing the goal kick, ensure the athlete is able to perform the proper approach and dry kicks in the clinic without aggravation of symptoms. Once they have demonstrated proper mechanics without compensations, they can add the ball and progress from short to long distances.

Section testing elements for return to kicking include the ability to perform full intensity kicks (at least 5-10 kicks in a row) in the clinic without symptom provocation, as well as full game play without symptom provocation.

SCRUM PROGRESSION

The purpose of the scrum is to restart play quickly, safely, and fairly after a minor infringement or stoppage. It is composed of eight players, typically forwards, who bind together to form a cohesive pack, first with each other and then against an opposing pack to compete for possession of the ball as it is rolled by the scrum half between the resultant tunnel that separates the two teams (Figures 3a and 3b).⁸⁵ Each scrum is composed of three units or rows: the front row (two props with a hooker between them), the second row (also referred to as locks), two flankers, and a number 8. Tight forwards include the two props, the hooker, and the two locks. Loose forwards include the two flankers and the number 8. In a sample of professional rugby players an average of 29 ± 6 scrums occurred per game with a mean duration of 5.8 ± 0.5 seconds per scrum.⁴⁵

Figure 3.

Front row of the scrum, a) composed of a hooker between two props, b) Scrum half preparing to roll the ball between 2 full scrum packs.

Relative to the incidence of other injuries that occur during the sport, scrum-related injuries are reportedly very small, typically cited at an average of less than 8% of all reported injuries sustained during game play.^5,86-89 However, the scrum is correlated with the highest risk per event for injury, in addition to the most days lost per event when compared to all contact events that occur during rugby.⁹⁰ Catastrophic injuries occurring during the scrum are not uncommon and have been reported to be as high as 40% of all reported catastrophic injuries.^91-93 While the incidence of these injuries is low, they have the propensity to cause debilitating acute or chronic injury.^92,94-97 Injury mechanisms of spinal injuries occurring from the scrum are typically classified as either hyperflexion or buckling,⁸⁵ which may cause acute cervical root injuries during matches or the repeated cumulative stresses in the same manner may contribute to lumbar disc injuries.⁹⁴

Multiple studies have investigated the biomechanics and force production of rugby scrummaging.^98-102 Preatoni et al⁹⁹ utilized an instrumented scrum machine to analyze the biomechanical demands of scrummaging. During the scrum, there is a characteristic force pattern that includes a short-duration peak at impact, a sharp decrease in force to its lowest level, followed by a steady escalation to an overall steady-state sustained force. Peak engagement forces ranged from 8700 to 16500 Newtons. When forces were normalized by total body weight amongst the scrum packs, there were no discrepancies in peak engagement force between genders or age level, except for international and elite players.

During the scrum, players must bind to a teammate using their entire upper extremity from shoulder to hand in order to grasp a teammate's body at or below the level of the axilla, which typically requires at least 90 degrees of shoulder horizontal abduction.¹⁰³ Due to their position between two props on either side, the hooker requires greater shoulder range of motion and greater end range shoulder strength to maintain this suspended position during the scrum. Isometric cervical strength is especially important for those in the front row due to the forces described previously for adequate stabilization of the cervical spine.

Amongst the props for each team there exists a loose head prop, who is only bound to the opponent's scrum by his inside shoulder, and a tight head prop, who is bound to the opponent's scrum between the opposing hooker and loose head prop. Requirements for the tight head prop will be greater than those for their loose head counterpart due to the more constricted and thus more vulnerable position. Players involved in the scrum must also be able to tolerate the physical demands of the crouched position. According to Quarrie et al¹⁰³ the range of motion requirements for scrummaging include 123 degrees of hip flexion, 107 degrees of knee flexion, and 12 degrees of ankle dorsiflexion.

Scrummaging requires dedicated strength training in the weight room for both the upper and lower extremities in addition to core stability, such as those listed in Table 3 and shown in Figures 4a- 4h. Emphasis should be placed on those exercises simulating the crouched position required for the scrum. In addition, promotion of triple extension should not be neglected, as lower extremity power production as a cohesively bound unit is essential for driving the scrum pack forward against a resisting opponent.

Table 3.

Strength Drills for Scrummaging and Tackling: perform 3x/week with at least 1 rest day in between

Upper Body Strength Cervical isometric drills Flexion, extension, lateral side-bending (right/left), rotation (right/left) Begin with self-resisted exercise and transition to theraband resistance Incorporate therapist applied perturbations to enhance stability, activation, and speed of reaction Shoulder horizontal abduction/adduction Scapular fly/chest fly with cable or free weights Prone plank upper extremity sliders Can also incorporate diagnonals Monitor for correct activation of scapular retractors during performance and decrease over-activation of upper trapezius Horizontal row Bent over with free weight or hanging from barbell Grip strengthening

Core Stability Core activation in horizontal/crouched position Begin with activation in hooklying then progress to sitting→standing→crouched Anti-flexion, anti-rotational stability Start from quadruped and progress to prone on unstable surfaces, such as prone over bosu or ball Incorporate therapist applied perturbations to enhance stability, activation, and speed of reaction

Lower Extremity Power High-load back squats Ensure proper activation of core stabilizing musculature with maintenance of proper lordotic curve High load cleans (progressing to clean and jerks when appropriate) Vertical jump Incorporate band resistance if available Burpee box jumps Promotion of triple extension (hip, knee, ankle)

Figure 4.

(a-h). Strength drills for scrimmaging: a) Resisted prone cervical extension over bench, b) Chest fly with dumbbells, c) Reverse fly with dumbbells, d) Horizontal row with dumbbells, e) Half kneeling press with lateral cable, f) Quadruped upper extremity flexion with contralateral lower extremity extension over ball, g) Side plank with shoulder abduction, h) Posterolateral upper extremity slide.

In addition, players attempting to return to scrummaging should do so in a functional progression (Table 4). It is encouraged that the clinician gradually incorporate simulated opponents before finally advancing to a full scrum (Figures 5a, 5b, 5c). A player may return to scrummaging in a competitive environment when he or she demonstrates the ability to perform full intensity scrummaging in practice with all eight forwards.

Table 4.

Field Progressions for Scrummaging

Without a partner (begin with 5-10 second bouts and gradually increase to 30 second bouts) Low prowler pushes Sprints with increasing weight as tolerated Resisted sport cord runs (upright) Resisted sport cord bear crawl

With one partner/opponent (must be able to tolerate positions for 20-30 seconds at a time Simple binding (interlocking position with another player) in a crouched position for positional tolerance Bind + synchronous squat Bind + 45 ° rotation in each direction

Sequential scrum transitions (perform progressions on separate days to ensure tolerance; begin with 5-10 minutes of practice time and allow progression if no pain reproduction) 3 on 3 (front row) 5 on 5 (front row + 2nd row) Full 8 member pack

Figure 5.

Field progressions for scrummaging performed with a partner, a) Binding for positional tolerance, b) Players performing squat in bound position, c) Rotations performed from bound position.

TACKLING, RUCKING, MAULING PROGRESSION

Tackling

Tackling is an essential component of the sport of rugby, and emphasis on proper technique should begin as early as possible in a player's career given that players are expected to develop and withstand tremendous forces without injuring themselves or others. A tackle is technically defined as an event that occurs on the field of play during which the ball carrier is held by one or more opponents, and either the ball or the hand of the arm carrying the ball makes contact with the ground. An average of 590 ± 50 completed tackles and an average of 67 ± 14 missed tackles per player occurred in a study investigating a professional New Zealand rugby team over two seasons.¹⁰⁴ In a two-season prospective cohort of 645 professional rugby union players from 13 English Premiership rugby union clubs, the flanker completed the highest number of tackles per match amongst all positions, with an average of 13 ± 6.⁹⁰ However, the frequency of being tackled was not significantly different between all positions.⁴⁵

With regards to injury, previous reports amongst senior and elite rugby players revealed that the most prevalent cause of injury was the tackle (24-58%), followed by the ruck (6-17%), and then the maul (12-16%).^{5,86,89,105-109} In a prospective cohort of 645 professional rugby players followed over two seasons, the most common injuries sustained during collision events were thigh muscle hematomas, head/facial fractures, knee and foot/ankle ligament injuries during the maul, calf muscle hematomas and foot/ankle ligament injuries during the ruck, shoulder ligament injuries and concussions while tackling, and thigh muscle hematomas and knee ligament injuries while being tackled.⁹⁰ Not surprisingly, ball carriers sustain more injuries to their lower rather than upper limb, while the opposite is true for the tackler.¹⁰⁴

The requirements for tackling are nearly identical to those for scrummaging. However, players are required to develop more power in a less controlled and more dynamic environment. Intuitively, those players who approach a contact situation with the greatest momentum typically produce the largest peak force during impact.¹¹⁰ Strength and conditioning drills to be performed prior to a player's return to tackling are outlined in Table 3.

As mentioned in the Scrum Progression section, grip strength is essential for the sport of rugby, as tacklers are required to pin their opponents to the ground before the phase is concluded. Therefore, suggested progressive grappling drills are essential to an athlete's successful return to competition. These drills may be performed by the clinician, a teammate, or a member of the coaching staff in an open area in the clinic or on the field. Beginning in a tall kneeling position the athlete should practice binding head on and then progressing to the side and from behind. Once this is completed, the athlete may begin to practice binding from a standing position utilizing the same intensity progression (Figure 6). For positional tolerance, the athlete should practice a stationary grapple to ensure proper positioning and absence of symptoms. Following this, the athlete should begin to bind before walking forward and then backwards while maintaining this bound position. Once this has been accomplished, the athlete should perform clockwise and counterclockwise circles while bound to an opponent. To challenge the returning player's reaction ability, the opponent may then change directions with an attempt to shake the athlete off. In an effort to simulate the dynamic nature and duration of a tackle the athlete may then begin practicing an explosive initial contact with an opponent. This initial contact may then be followed by a resisted drive against an opponent with a final progression towards shaking off an opponent before the addition of a sprint.

Figure 6.

Tackle performed against a standing opponent.

Once this progression is successfully completed without symptom provocation, the athlete may advance to drills performed on the field. All field tackling drills should be executed in a gradually progressive fashion. It is the authors’ recommendation to begin initially at 25% intensity prior to progressing to 50%, 75%, and finally 100% intensity as tolerated. It has been previously reported that fatigue can decrease an athlete's neuromuscular control, performance, and lower extremity mechanics.^111-120 Additionally, Gabbett¹²¹ reported a decrease in rugby players’ tackling ability in addition to other performance elements as exercise intensity increased, resulting in a progressively fatigued state. If available, it is recommended that a tackling dummy or shield be utilized preceding a live opponent. Forwards are typically involved in tackling from a shorter distance, whereas backs are commonly involved in more open-field tackling events at greater velocities.⁸¹ Therefore, in an effort to closely correlate position-specific demands, the distances should be varied accordingly. In addition, tackles should be performed at a variety of angles to mimic the assorted demands required during gameplay.

In an effort to mimic the reactive ability and on-field decision making required for tackling, three cones should be set up to create two running lanes for an opponent. An opponent is instructed to sprint towards the cones before finally choosing one of the two lanes to run through before being bound by the recovering athlete from a standing position. The athlete's position is then transitioned to prone facing the opponent before transitioning to prone facing away from the opponent. This sequence should then be progressed from binding to tackling utilizing the previously mentioned graduated advancement of intensity. Gabbett¹²¹ lists the following as technical criteria for proficient tackling in rugby, “accelerating into the contact zone; contacting the target in the center of gravity; contact the target with the opposite shoulder to leading leg; body position square/aligned; arms wrapping around the target on contact; leg drive on contact; watching the target onto the shoulder; and center of gravity forward of base of support”. ¹²¹, p. 626. Once the athlete is able to demonstrate proficient technique from a rested state, he or she should then be evaluated using a repeated-effort protocol in order to induce fatigue.¹²¹

Rucking is a common event occurring immediately following a tackle in which a player is effectively pinned to the ground and the tackled player places the ball on the ground (Figures 7a and 7b). The site where the ball is placed demarcates the area of possession for the offensive team. Players from both teams form opposing forces in an attempt to either maintain or gain possession utilizing various strategies and techniques, typically involving a charge leading with the shoulder. Amongst 13 professional teams, an average of 142.5 rucks occurred per match.⁹⁰ Although any player may participate in a ruck, the forwards are typically involved more frequently than the backs.⁴⁵

Figure 7.

A player placing the ball after being tackled, b) Players from both sides form a ruck to compete for possession of the ball.

A maul is formed if the ball carrier is unable to be successfully pinned to the ground and at least one opponent and one bound teammate hold the ball carrier upright. The play must continue to move towards a goal line and may not remain stationary for more than five seconds. An average of 18.4 mauls have been reported to occur in an individual professional match.⁹⁰ The requirements for rucking and mauling are nearly identical to those required for scrummaging. However, rucks require more power development in a less controlled and more dynamic environment than scrummaging. In addition, mauling requires power development while the athlete maintains a more upright position. Forwards participate in an average of 3.2 times more rucks and mauls combined than backs.⁴⁵

A useful drill for the recovering player is to simulate a player using a tackle bag by laying the bag on the ground to simulate a ruck or upright to simulate a maul. The player then charges towards the bag in an attempt to “clear” the ruck or advance the maul. Tackling shields may be used to simulate opposing players initially before progressing to live opponents. As the player is able to demonstrate competence with these drills, the intensity and angle of the charge may be manipulated further. Return to full gameplay should be done so in conjunction with successful completion of the other aspects of gameplay in which he or she is involved as discussed in the previous sections of this commentary.

CONCLUSION

As evidenced by the detailed proposed guidelines, the sport of rugby places very specific and unique demands on the body when returning a rugby player to full participation. Rehabilitation may be tailored to the position played, the level of the athlete, and the type and involvement of the injury. The intention of this proposed program is to provide a general outline for rehabilitation specialists to utilize for rugby players during rehabilitation that takes into account the unique aspects of functional performance and return to sport phases in order to prepare an athlete for return to full gameplay. It also provides educational components on general gameplay, testing components, suggested specific movement progressions, and sport- and position-specific progressions. Prior to initiation of this return to sport program, all athletes should demonstrate achievement of the baseline requirements in order to decrease risk of re-injury and to ensure safe and efficient return to sport.