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

2008-2011 – Catastrophic Scrum Injuries – can this influence the game going forward?. Dr Wayne Viljoen Dawie Theron James Brown Clint Readhead Dr Evert Verhagen Prof Willem van Mechelen Prof Mike Lambert. SOME DESCRIPTIVE STATS. ASCI specific data - basics.

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

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  1. 2008-2011 • – Catastrophic Scrum Injuries – can this influence the game going forward? • Dr Wayne ViljoenDawie Theron • James BrownClint Readhead • Dr Evert Verhagen • Prof Willem van MechelenProf Mike Lambert

  2. SOME DESCRIPTIVE STATS

  3. ASCI specific data - basics • There have been 45 ASCI’s since 2008, all of which have occurred in males. • This equated to an average annual incidence of 1.73 ASCI’s per 100 000 players (95% CI’s: 0.72 – 2.74) and an average annual incidence of 1.04 permanent ASCI outcomes per 100 000 players (95% CI’s: 0.25 – 1.82). • Seven % of the ASCI’s (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).

  4. ASCI specific data – basics • Fifty-eight % (n = 26 of 45) of all ASCI’s 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% CI’s: 3.2 – 80.2).

  5. ASCI specific data – Positional Risk • 40 ASCI were related to 15-a-side, hence were compared further for positional risk • The hooker and loose-forward positional groupings were associated with 38% (n = 15 of 40) and 25% (n = 10 of 40) of all ASCI’s. • Together, the hooker, prop, and lock positional grouping (tight five) accounted for all the scrum injuries. • When examining permanentinjuries, 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.

  6. Proportion of all ASCI per position per phase of play

  7. Position of Injured Player Hooker (n = 15) Prop (n = 5) Front Row ASCI = 20, 50% PERMANENT ASCI FRONT ROW n = 15/18, 83%, Not Provided = 2 PERMANENT ASCI HOOKER n = 12/15, 80%

  8. Proportion of Permanent ASCI per position per phase of play

  9. EVENT CAUSING INJURY

  10. Tackler n = 8/16, 50% Event causing injury • Tackle ASCI (n = 17, 38%) • Scrum ASCI (n = 19, 42%) Ball carrier n = 8/16, 50% Not provided = 1

  11. Impact on engagement n = 10/18, 56% Event causing injury • Tackle ASCI (n = 17, 38%) • Scrum ASCI (n = 19, 42%) Collapsed scrum n = 7/18, 39% Popping out n = 1/18, 6% Not provided = 1

  12. n = 36/45, 80% PERMANENT ASCI TACKLE n = 8/16, 50%, Not provided = 1 Event causing injury • Tackle ASCI (n = 17, 38%) • Scrum ASCI (n = 19, 42%) PERMANENT ASCI SCRUM n = 14/17, 82%, Not provided = 2

  13. Proportion of All ASCI per phase of play

  14. Proportion of Permanent ASCI per phase of play

  15. MATCH RELATED TRENDS • 2008 2011 • THUS FAR

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

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

  18. INITIAL IRB SCRUM RESEARCH KEY FINDINGS…

  19. Different engagement techniques • Comparison across playing levels BIOMECHANICS OF THE RUGBY SCRUM METHODS: PROJECT STRUCTURE 21.NOVEMBER .2011 PHASE 1 Machine Scrummaging Phase 2 Live Scrummaging CONTACTS Dr Grant Trewartha, g.trewartha@bath.ac.uk • Wearable sensors • Techniques and playing levels Slides used with Permission 25

  20. BIOMECHANICS OF THE RUGBY SCRUM METHODS: STUDY DESIGN 21.NOVEMBER .2011 • Cross-sectional (single shot) design • Field-based study – outdoor, natural turf, simulated training • Teams recruited into six different playing levels (total of 34 teams): • School (under 18) • Academy / University • Men Community • Women • Elite Club • International Standard • Modify the engagement technique (six techniques) • Compare: • Playing level • Technique • Technique across playing levels CONTACTS Dr Grant Trewartha, g.trewartha@bath.ac.uk Slides used with Permission 26

  21. BIOMECHANICS OF THE RUGBY SCRUM METHODS: ENGAGEMENT TECHNIQUES 21.NOVEMBER .2011 • Final choice of engagement techniques decided by the ‘steering group’, international group of scrum experts convened by IRB • Engagement techniques: • Hit & Hold • Double Shove • Three-Stage Call • Passive Engagement • Engage as 7, add number 8 (7+1) • Engage as front 5, add back row (5+3) CONTACTS Dr Grant Trewartha, g.trewartha@bath.ac.uk Slides used with Permission 27

  22. BIOMECHANICS OF THE RUGBY SCRUM METHODS: FORCE MEASUREMENT 21.NOVEMBER .2011 • Scrum machine fixed to ground (spikes and straps) • Data sampled @ 500 Hz • All engagement commands produced by pre-recorded audio files (consistency of timing) CONTACTS Dr Grant Trewartha, g.trewartha@bath.ac.uk Slides used with Permission 28

  23. BIOMECHANICS OF THE RUGBY SCRUM METHODS: VIDEO ANALYSIS 21.NOVEMBER .2011 CONTACTS Dr Grant Trewartha, g.trewartha@bath.ac.uk Slides used with Permission 29

  24. BIOMECHANICS OF THE RUGBY SCRUM METHODS: DATA FLOW 21.NOVEMBER .2011 CONTACTS Dr Grant Trewartha, g.trewartha@bath.ac.uk Slides used with Permission 30

  25. BIOMECHANICS OF THE RUGBY SCRUM METHODS: TESTING COMPLETED 21.NOVEMBER .2011 • 41 forward packs tested across playing levels: • U18 - 6 • Academy/Uni - 8 • Women - 4, • Community - 6 • Elite - 11 • International Standard - 6 • All teams performed 4-8 scrums per engagement condition • A total of 1220 scrums to be analysed • 34 packs analysed CONTACTS Dr Grant Trewartha, g.trewartha@bath.ac.uk Slides used with Permission 31

  26. BIOMECHANICS OF THE RUGBY SCRUM ANALYSIS: KINEMATICS 21.NOVEMBER .2011 CONTACTS Dr Grant Trewartha, g.trewartha@bath.ac.uk Slides used with Permission 32

  27. BIOMECHANICS OF THE RUGBY SCRUM ANALYSIS: KINEMATICS 21.NOVEMBER .2011 CONTACTS Dr Grant Trewartha, g.trewartha@bath.ac.uk Slides used with Permission 33

  28. BIOMECHANICS OF THE RUGBY SCRUM RESULTS: Peak Compression @ engagement 21.NOVEMBER .2011 CONTACTS Dr Grant Trewartha, g.trewartha@bath.ac.uk Slides used with Permission 34

  29. BIOMECHANICS OF THE RUGBY SCRUM RESULTS: Compression - sustained 21.NOVEMBER .2011 CONTACTS Dr Grant Trewartha, g.trewartha@bath.ac.uk Slides used with Permission 35

  30. BIOMECHANICS OF THE RUGBY SCRUM RESULTS: Time of Onset 21.NOVEMBER .2011 CONTACTS Dr Grant Trewartha, g.trewartha@bath.ac.uk Slides used with Permission 36

  31. BIOMECHANICS OF THE RUGBY SCRUM RESULTS: Comparing different levels 21.NOVEMBER .2011 Grouped data– peak compression force @ engagement (Hit & Hold) CONTACTS Dr Grant Trewartha, g.trewartha@bath.ac.uk Slides used with Permission 37

  32. BIOMECHANICS OF THE RUGBY SCRUM RESULTS: Comparing different techniques 21.NOVEMBER .2011 Elite data– peak compression force @ engagement * CONTACTS Dr Grant Trewartha, g.trewartha@bath.ac.uk Slides used with Permission 38

  33. BIOMECHANICS OF THE RUGBY SCRUM RESULTS: Comparing different techniques 21.NOVEMBER .2011 Elite data– peak downward force @ engagement CONTACTS Dr Grant Trewartha, g.trewartha@bath.ac.uk Slides used with Permission 39

  34. BIOMECHANICS OF THE RUGBY SCRUM RESULTS: Comparing different techniques 21.NOVEMBER .2011 Elite data– average compression force during sustained CONTACTS Dr Grant Trewartha, g.trewartha@bath.ac.uk Slides used with Permission 40

  35. BIOMECHANICS OF THE RUGBY SCRUM DISCUSSION – PHASE 1 21.NOVEMBER .2011 • Forces: • Differences between conditions • Passive vs 5+3 vs Hit&Hold/3-stage/7+1 • Passive reduced compression (50%) and downward (20%) • Packs maintained sustained forces in Passive • Differences between playing levels • U18/Women, Academy/Community, Elite/International • Kinematics: • No consistent between-level differences • Passive reduces ‘closing speeds’, therefore accelerations • Passive lowered maximum ‘hazard index’ CONTACTS Dr Grant Trewartha, g.trewartha@bath.ac.uk Slides used with Permission 41

  36. BIOMECHANICS OF THE RUGBY SCRUM DISCUSSION – INJURY MECHANISMS 21.NOVEMBER .2011 • Given magnitude of forces and speed of engagement imperative to ensure direct impact on top of head is avoided • Scrummaging has….. • High forces including vertical and lateral shear forces • Geometric misalignment • Constrained head motions • Constrained body segment motion • Repeated 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, g.trewartha@bath.ac.uk Slides used with Permission 42

  37. WHAT IS THE WAY FORWARD FOR SCRUMS?

  38. Where to from here? • The high forces during scrum engagement in the modern era is potentially the result of: • A change in scrumming technique • Bigger, heavier players • Faster engagement speeds i.e. the “Hit” • Given the very high forces, heavier packs and faster engagement, it is imperative to control the engagement sequence to avoid direct impact on the head • What 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?

  39. 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”?

  40. Where to from here? • Some interesting scrum stats: • 1995 – WC Final game was played over 100 minutes – ball in play 32min • 2009 – 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 scrum • IRE vs. ENG 6N 9 penalties in SCRUMS, total cost to ball in play more than 5 min • What brings people back to watch?

  41. Where to from here? • According to the IRB Game Analysis Group: • between 15-28 scrums per game • between 14-29% tries scored from scrum possession • teams retain 83-91% of their own scrum possession • With 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 Law’s 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?

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