Dr Wayne Viljoen Dawie Theron James Brown Clint Readhead Dr Evert Verhagen

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Dr Wayne ViljoenDawie TheronJames BrownClint Readhead Dr Evert VerhagenProf Willem van MechelenProf Mike Lambert2008-2011 Catastrophic Scrum Injuries can this influence the game going forward?1

SOME DESCRIPTIVE STATS

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3Catastrophic rugby injuries (2001-2011)Acute Spinal Cord Injury (ASCI) [n = 140]Traumatic Brain Injury (TBI) [n = 14]Cardiac events [n = 6]Unknown [n = 4]TOTAL [n = 164]

ASCI specific data - basicsThere have been 45 ASCIs since 2008, all of which have occurred in males. This equated to an average annual incidence of 1.73 ASCIs per 100 000 players (95% CIs: 0.72 2.74) and an average annual incidence of 1.04 permanent ASCI outcomes per 100 000 players (95% CIs: 0.25 1.82). Seven % of the ASCIs (n = 3 of 42) were fatal, 26% (n = 11 of 42) resulted in Quadriplegia, 31% (n = 13) resulted in neurological deficit and the remaining 36% (n = 15 of 42) were classified as Near Misses (outcome not provided in n = 3 cases). Henceforth for further comparison, outcomes of ASCI were also grouped as either Permanent (Neurological Deficit, Quadriplegia, Fatal) or Non-Permanent (near miss).

ASCI specific data basicsFifty-eight % (n = 26 of 45) of all ASCIs occurred at Senior level with an estimated player base of 121 663 players, resulting in a significantly higher incidence (7.12 per 100 000 players; 2.38 11.87) than Junior level (1.20 per 100 000 players; 0.26 2.13), with an estimated player base of 529 483 players. In Senior players, 85% (n = 22 of 26) of their injuries had permanent outcomes in comparison to 26% (n = 5 of 19) in Junior players. Permanent injuries to Senior players (6.03 per 100 000 players; 1.66 10.39) were significantly higher than to Junior players (0.31 per 100 000 players; -0.16 0.79). Furthermore, when examining in isolation the total of 27 permanent injuries the player was significantly more likely to be a Senior (82%, n = 22 of 27) rather than Junior level player (Absolute Value - Odds Ratio: 16.1, 95% CIs: 3.2 80.2).

ASCI specific data Positional Risk40 ASCI were related to 15-a-side, hence were compared further for positional riskThe hooker and loose-forward positional groupings were associated with 38% (n = 15 of 40) and 25% (n = 10 of 40) of all ASCIs. Together, the hooker, prop, and lock positional grouping (tight five) accounted for all the scrum injuries. When examining permanent injuries, only the forwards were represented (prop, hooker, lock and loose-forward). Of these permanent outcomes in isolation, the hooker alone accounted for 46% (n = 12 of 26) of all injuries, 83% of which (n = 10 of 12) were as a result of the scrum.

Proportion of all ASCI per position per phase of playPosition of Injured Player

Hooker (n = 15)Prop (n = 5)

Front Row ASCI = 20, 50%PERMANENT ASCIFRONT ROW n = 15/18, 83%, Not Provided = 2PERMANENT ASCIHOOKERn = 12/15, 80%

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Proportion of Permanent ASCI per position per phase of play

EVENT CAUSING INJURY

11Event causing injuryTackle ASCI (n = 17, 38%)Scrum ASCI (n = 19, 42%)

Tackler n = 8/16, 50%Ball carriern = 8/16, 50%Not provided = 1


Impact on engagementn = 10/18, 56%Collapsed scrumn = 7/18, 39%Not provided = 1Popping outn = 1/18, 6%


n = 36/45, 80%PERMANENT ASCITACKLEn = 8/16, 50%,Not provided = 1PERMANENT ASCISCRUMn = 14/17, 82%, Not provided = 2

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Proportion of All ASCI per phase of play

Proportion of Permanent ASCI per phase of play

MATCH RELATED TRENDS 2008 2011THUS FAR

17NP"Miss"Neuro.Quad.FatalTotalScrum (n = 16)2008010102200900120320101111042011003317Tackle (n = 14)2008020002200912111620100120032011011103Ruck (n = 6)2008000000200901000120100201032011011002Total2121011136

Of the 27 Permanent ASCI, the Scrum had the strongest tendency to cause Permanent outcome (n = 14/27, 52%)

Of the 27 Permanent ASCI, the Hooker accounted for 46% of all Permanent outcomes (n = 12/26, Not provided = 1)

INITIAL IRB SCRUM RESEARCH KEY FINDINGS23

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METHODS: PROJECT STRUCTUREPHASE 1Machine Scrummaging

Wearable sensors Techniques and playing levels Different engagement techniquesComparison across playing levels

Phase 2Live ScrummagingCONTACTS Dr Grant Trewartha, [email protected] .2011BIOMECHANICS OF THE RUGBY SCRUMSlides used with Permission

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METHODS: STUDY DESIGNCross-sectional (single shot) designField-based study outdoor, natural turf, simulated trainingTeams recruited into six different playing levels (total of 34 teams):School (under 18)Academy / UniversityMen CommunityWomenElite ClubInternational StandardModify the engagement technique (six techniques)Compare:Playing levelTechniqueTechnique across playing levelsCONTACTS Dr Grant Trewartha, [email protected] .2011BIOMECHANICS OF THE RUGBY SCRUMSlides used with Permission

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METHODS: ENGAGEMENT TECHNIQUESFinal choice of engagement techniques decided by the steering group, international group of scrum experts convened by IRBEngagement techniques:Hit & HoldDouble ShoveThree-Stage CallPassive EngagementEngage as 7, add number 8 (7+1)Engage as front 5, add back row (5+3)CONTACTS Dr Grant Trewartha, [email protected] .2011BIOMECHANICS OF THE RUGBY SCRUMSlides used with Permission

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METHODS: FORCE MEASUREMENT28

CONTACTS Dr Grant Trewartha, [email protected] .2011BIOMECHANICS OF THE RUGBY SCRUMScrum machine fixed to ground (spikes and straps)Data sampled @ 500 Hz

All engagement commands produced by pre-recorded audio files (consistency of timing)Slides used with Permission

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METHODS: VIDEO ANALYSISCONTACTS Dr Grant Trewartha, [email protected] .2011BIOMECHANICS OF THE RUGBY SCRUM

Slides used with Permission

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METHODS: DATA FLOWCONTACTS Dr Grant Trewartha, [email protected] .2011BIOMECHANICS OF THE RUGBY SCRUM


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METHODS: TESTING COMPLETED41 forward packs tested across playing levels: U18 - 6 Academy/Uni - 8 Women - 4, Community - 6 Elite - 11International Standard - 6All teams performed 4-8 scrums per engagement conditionA total of 1220 scrums to be analysed34 packs analysedCONTACTS Dr Grant Trewartha, [email protected] .2011BIOMECHANICS OF THE RUGBY SCRUMSlides used with Permission

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ANALYSIS: KINEMATICSCONTACTS Dr Grant Trewartha, [email protected] .2011BIOMECHANICS OF THE RUGBY SCRUM


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ANALYSIS: KINEMATICSCONTACTS Dr Grant Trewartha, [email protected] .2011BIOMECHANICS OF THE RUGBY SCRUM


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RESULTS: Peak Compression @ engagementCONTACTS Dr Grant Trewartha, [email protected] .2011BIOMECHANICS OF THE RUGBY SCRUM


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RESULTS: Compression - sustainedCONTACTS Dr Grant Trewartha, [email protected] .2011BIOMECHANICS OF THE RUGBY SCRUM


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RESULTS: Time of OnsetCONTACTS Dr Grant Trewartha, [email protected] .2011BIOMECHANICS OF THE RUGBY SCRUM


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RESULTS: Comparing different levelsGrouped data peak compression force @ engagement (Hit & Hold)

CONTACTS Dr Grant Trewartha, [email protected] .2011BIOMECHANICS OF THE RUGBY SCRUM

37Slides used with Permission

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RESULTS: Comparing different techniquesElite data peak compression force @ engagement

CONTACTS Dr Grant Trewartha, [email protected] .2011BIOMECHANICS OF THE RUGBY SCRUM*38Slides used with Permission

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RESULTS: Comparing different techniquesElite data peak downward force @ engagement

CONTACTS Dr Grant Trewartha, [email protected] .2011BIOMECHANICS OF THE RUGBY SCRUM39Slides used with Permission

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RESULTS: Comparing different techniquesElite data average compression force during sustained

CONTACTS Dr Grant Trewartha, [email protected] .2011BIOMECHANICS OF THE RUGBY SCRUM40Slides used with Permission

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DISCUSSION PHASE 1Forces:Differences between conditionsPassive vs 5+3 vs Hit&Hold/3-stage/7+1Passive reduced compression (50%) and downward (20%)Packs maintained sustained forces in PassiveDifferences between playing levelsU18/Women, Academy/Community, Elite/InternationalKinematics:No consistent between-level differencesPassive reduces closing speeds, therefore accelerationsPassive lowered maximum hazard indexCONTACTS Dr Grant Trewartha, [email protected] .2011BIOMECHANICS OF THE RUGBY SCRUMSlides used with Permission

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DISCUSSION INJURY MECHANISMSGiven magnitude of forces and speed of engagement imperative to ensure direct impact on top of head is avoidedScrummaging has..High forces including vertical and lateral shear forcesGeometric misalignmentConstrained head motionsConstrained body segment motionRepeated loading. a situation which has the potential to produce the repetitive sub-critical injuries that in theory could lead to chronic pain and early degenerative changes to the cervical and lumbar spine.

CONTACTS Dr Grant Trewartha, [email protected] .2011BIOMECHANICS OF THE RUGBY SCRUMSlides used with Permission

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WHAT IS THE WAY FORWARD FOR SCRUMS?43

Where to from here?The high forces during scrum engagement in the modern era is potentially the result of:A change in scrumming techniqueBigger, heavier playersFaster engagement speeds i.e. the HitGiven the very high forces, heavier packs and faster engagement, it is imperative to control the engagement sequence to avoid direct impact on the headWhat is the purpose of the scrum according to Law? to restart play quickly, safely and fairly, after a minor infringement or a stoppage Are we doing this with the original intent?Modern scrumming involves a high initial impact or hit on engagement, followed by sustained pushing forces throughout the scrum Is this safe, and does this serve the original purpose of the scrum? Is this indeed in line with the Laws intended?Where to from here?On 1 January 2007, the CTPE Law was implemented this was designed to standardise the distance between opposing packs and to reduce the forces at engagement Is this what we are currently doing? Have the forces at engagement been reduced? Does the current execution of the scrum limit or increase the risk of catastrophic cervical spinal injury during the hit?

Where to from here?Some interesting scrum stats: 1995 WC Final game was played over 100 minutes ball in play 32min2009 average Super Rugby ball in play 38 min (14 years to add 6 min!)Current Super Rugby Average time 3-4 min ball out of play because of resets and penalties due to the scrumIRE vs. ENG 6N 9 penalties in SCRUMS, total cost to ball in play more than 5 minWhat brings people back to watch?

Where to from here?According to the IRB Game Analysis Group: between 15-28 scrums per gamebetween 14-29% tries scored from scrum possessionteams retain 83-91% of their own scrum possessionWith such high retention of ball and so few scrums, is the hit still justifiable? And given the risk of permanent catastrophic cervical spinal injury? Especially in the amateur game, which is mass participation based?The Laws also state: Each player in the front row and any potential replacement(s) must be suitably trained and experienced Is this so? Do we see that at Amateur level rugby? Who exactly determines this?

Where to from here?Reaching a high impact velocity leading to the hit at engagement is a result of coaches and players to beat the opposition to the middle or generate high force to attempt to limit the oppositions forward motion (Bath Univ. IRB Scrum Research group)Keep in mind the rebound- or damping effect that a larger hit creates, which results in suboptimal force production for a short period of time, before a sustained pushing force has been achievedTo a certain extent, the hit on engagement is initially counterproductive to sustained pushing forces that follow, especially in an event where domination is determined over the initial few seconds of the ball being put into the scrumAn important part of scrumming should be to maximise scrumming force, after the engagement; this would increase the chances of pushing the opposition off the ball

Where to from here?Sustained force generation during the scrum is a function of player technique and forward pack cohesion, whereas the force during the engagement is more related to pack weight and speed to the hitSustained pushing force manifests after the ball has been put into the scrum, and largely determines more or less effective scrumming

Where to from here?There is great need to manage catastrophic injury risk, and simultaneously maximise performance of the scrumEven though scrum injuries are few, they are the most severeThe risk of injury per event in the scrum is the highest of all contact events in the gameBecause the scrum is a controllable event, it should be more amenable to intervention and to look towards reducing the risk of injury furtherPreventative strategies of the game must be maximised towards preventing permanent disability or death, and therefore the hit should be removed from Amateur rugby

Where to from here?Injury prevention should be direct at the following:The Laws of the scrum (both Amateur and Professional separately)Techniques of scrumming (both Amateur and Professional separately)Correct Law interpretation and enforcement by the refereesCoaching of the correct Laws, and interpretations by the coachesPlayer skill developmentProgressive Long Term Coaching, Refereeing and Player Development PathwaysWhere to from here?What is the proposed way forward?Remove the hitBring back the scrumRelook at what the Laws originally intendedMove to Passive engagement across the board = first prizeAnd if not, then in the interim, at least to the majority of Amateur levelsPassive engagement does not diminish the scrum, it should make it safer, and place more emphasis on scrummingShould the hit be maintained at certain levels, then there should be an abridged version or mini-hit to transition from no hit to full hitI.e. bring the front rows closer together i.e. ear-to-ear, and have them pre-bound and in their respective channels before the engagementClothing modifications?

Where to from here?Advantages of Passive engagement:It removes the hit out of the equation, which will remove a large portion of catastrophic and permanent cervical spinal injuriesSignificantly lower compressive forces (about 50% reduction, and potentially more, with a closer setup position)Significantly lower downward forces (about 20-40% reduction, and potentially more, with a closer setup position) this will reduce the chances of collapse, and associated catastrophic cervical spinal injuryLess horizontal angle deviation at high and peak forces, which lowers the hazard indexPlayers are better in alignment to sustain and accommodate the forces generatedPassive engagement can remove high initial impact forces, and does not negatively impact the power generating capacity of the scrum during the actual pushing phase, in fact the sustained pushing forces generated are generally higher than most impact engagement techniquesPassive engagement leads to less angled lateral head, neck and torso movement, and also less downward angles of the head, neck and torso

AcknowledgementsThe Bath University IRB Scrum Research GroupDrs Trewartha, Preatoni, Stokes and EnglandThe IRBThe SA Scrum Smart working groupWayne Viljoen, Clint Readhead, Dawie Theron, Balie Swart, Tappe Henning, Andre Watson, Justin Durandt, Hilton Adonis, Nico Serfontein, Graham BentzThe University of Cape Town and Vrije Universiteit Research groupsProf Mike Lambert, James Brown, Dr Evert Verhagen, Prof Willem van MechelenThe SARU Medical team The Chris Burger/Petro Jackson Players Fund

THANK YOU FOR YOUR ATTENTION!58All12547.04813546512583.19538344043361.77769980111847.26696087892773.57517805912449.46538117996148.01406795841763.86632829231503.714948722811982.48671440112922.49065956013009.726185025110552.62203832373230.45864492992381.8890403128

AllConditionForce [N]

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WomenConditionForce [N]

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Hit&HoldCategoryForce [N]

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Dr Wayne Viljoen Dawie Theron James Brown Clint Readhead Dr Evert Verhagen

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