“Head Impacts” in

Semi Professional

Rugby

Hamish Osborne

Head Impacts in Rugby Union

• Concussion risk goes up with concussion

• Concussion – Depression Link

• Contact Sport – Neurcognitive Disease

Link

Subconcussive Hits

This data showed the concussive threshold risk is greatly elevated when the head was subject to peak linear acceleration of greater than 98 gravitational forces (g) and peak rotational acceleration of greater than 6432 rad/s2

• Data from the Super 15 rugby 2013 season shows that midfield backs are the most common ball carriers and that loose forwards make the most tackles (15 of the top 20 tacklers in the 2013 season were flankers). Its therefore not surprising that the highest rates of concussion occur in inside and midfield backs, followed by loose forwards (4.4, 5.9 and 4.4 per 1000 player hours vs. the less mobile locks at 1.4/1000 player hours).12 Fuller et al (2010) confirmed that high speed ball carrying is also a significant risk for concussion where the relative risk of either the ball carrier or the tackler being concussed is doubled when the ball carrier is running at speed.13 Thus both the back and the forwards tackling them present the highest at risk groups.11,13

Hits by player groups

Front Row Inside Bk Lock Loosies Outside Backs

Linear hit by weight

Hits by event

Carry Coll Ruck Scrum Tackle Loosies

Outsi

Snapshot of results

Biggest Impact (g) Number of impacts Number above 60g

Prop 230 32 7

Hooker 233 120 8

Prop 284 74 5

Lock 225 53 1

Lock 231 115 10

Flanker 37 7 0

Flanker 277 153 8

8 209 59 3

9 229 49 6

10 123 40 6

11 141 36 5

12 230 95 12

13 224 47 2

14 249 68 5

15 69 65 2

Hooker 193 23 4

1 284 85 10

3 212 96 4

Flanker 281 56 4

Flanker 323 86 10

12 285 48 2

9 41 6 0

11 248 51 13

Average 211 64 6

The Problem

• 407 hits mapped to events from 6 games

• Single Game Data showed 64 hits per player

Subconcussive Blows

• Rugby Data

– Range of hits 10-169 G

– 564 per player per season

– 4643 hits per season that exceeded threshold

So…

• Ive been thinking about the next question

– The next grant application

– What to tell the media

My suggestion

• When scientists tell us things like

• We should be very skeptical

HOW MANY HITS DID WE MAP

407 div 15 div 6 = 4.5 hits per player per game

THE NEXT QUESTION

If more work is to be done we need to work out the sensor problem

Until then no further research should be done

Thanks

• Dunedin School of Medicine Deans Bequest Fund

• South Island Brain Injury Research Group (SIBIRG)

• Otago Rugby Team

• New Zealand Rugby (Dr Ian Murphy)

• World Rugby

• Every Player we played

• CSx Concussion Management Systems

• Dr Daneille Salmon– Jayden Pinfold

– Lorenz Kissling

• Sky Sport

• Hayden Croft