resed
rrh that addresses other rugby
axlesshould
Ix!not«l). Again, as rugby-rdattd
researdJhas terdri
tofaus
ongeneral injury, idmtifi«i risk factors associatai SjXrifo:ally with MTBI are
minimal. Hau.ec£r, itis assurmd that MTBI is, in
many resp«:ts,likely
to Ix! inamad under similar wndit:i.oosto tmse of
runMTBI
rehuriinjuries.
Oru:efXJtmtial risks are
�cO'lSideration of
thesein
rektticn w �measures etrn
Ix! addresS«!. Sectim 5.2
reviewsthe
arrasof
rulec
�,
cmdJing t«hniques,
useof
prot:a:tir£ equipnmt and impraurl canditimingWid?
are considerrripertirmt
wthe precmtion of MTBI in
rugby.
5 . 1 RISK FACTORS ASSOCIATED WITH RUGBY
Whilst certain factors associated with sport-related activities are recognised as having little impact on the potential of all athlete to sustain MmI, others have been shown to
increase the athlete's likelihood that such an injury may result. This section reviews those
GIAPTER 5 PREVENTION
5.1.1 Grade and Age
An early New Zealand study revealed that the rate of injuries sustained during winter sporting activities of rugby, rugby league, and soccer was related to the player's grade and age, with senior grade and older players more frequently injured (Lingard et al., 1976). Dalley et al. (1982) provided partial support for this earlier outcome, as their investigation of school and club grade rugby revealed that players in the Senior I grade incurred most of the injuries. This fmding was attributed to the larger size and strength of the players, the greater vigor, motivation and competition demands, and more consistent and competitive exposure to the game (Dalley et al., 1982). However, with respect to age, the early finding has since gone largely unsupported as more recent rugby-related studies have reported younger players incur more injmy than their older counterparts. A South African investigation identified that while injuries in general were shown to increase across age groups, the peak rate of injmy was associated with players under 19 years of age (Roux et al., 1987). In New Zealand, a similar trend has been observed with injuries found to be most common in the 16-20 year age group, although similar numbers were also found in the 21-25 year age group (Dalley et al., 1992).
The predisposition for younger players, in particular those under 19 years of age, to incur a greater number of injuries has also been identified in different sporting codes. Estell, Shenstone, and Barnsley (1995) revealed this trend in a cross-sectional investigation of an elite rugby league club and attributed it to an interaction of three factors reflective of this age group: (1) continual remodelling and realignment of body tissue; (2) a high degree of physical intensity and strength in their play; and (3) "a misplaced sense of confidence" (p. 96) in their skill level. On the basis of this argument, injmy incidence is not considered to be as high for older players as they are more physically mature and have greater playing experience, which may prevent them from encountering potentially harmful situations on the field (Estell et al., 1995).
rnAPTER 5 PREVENTION
5 . 1 .2 Time of Season
Injuries in rugby have been found to be more prevalent in the early stages of the season as opposed to the later stages. Observations made by Dalley et al. (1992) showed that early season games carried a greater risk of injury with 46% of all injuries occurring in early autumn (April) while only 1 % of injuries occurred in spring (September). TIlls same trend was also reported by Garraway and Macleod (1995) and Roux et al. (1987) in their respective investigations of Scottish and South African rugby. Factors thought to contribute to this trend include the relatively low level of match fitness at the start of a season (Sparks, 1985; Roux et al., 1987; Dalley et al., 1982), the keenness and increased vigour of the players (Sparks, 1985; Dalley et al., 1982), and the hard condition of the ground after the summer months (Dalley et al., 1982). Alsop et al. (2000) stated that the decrease in injury over time did not appear to be a consequence of underreporting end of
season ffiJunes.
5.1.3 Period of Game
Injuries in team sports predominantly occur during competition as opposed to training and preseason games. Competitive rugby games reportedly produce 71.3% - 80.0% of all injuries sustained (Roux et al., 1987; Dalley et al., 1992; Bird et al., 1998). With respect to injuries sustained during training, the rates vaty from 5% (Dalley et al., 1992) to 28.7% (Roux et al., 1987), and for preseason games range from 8% - 12% (Bird et al., 1998; Dalley et al., 1992).
With respect to match play, the majority of all injuries (55% - 61.7%) appear to be incurred in the second half, irrespective of player level (Lingard et al., 1976; Dalley et al., 1992; Wekesa et al., 1996). This finding is typically attributed to the player's experience of fatigue in this period of the game. However, there is also evidence that no differ.ence in injury rate between halves exists. Bird et al. (1998) reported that 46% of injuries were
a-IAPTER 5 PREVENTION
sustained in the first half, and 40% in the second half, with 14% of injury events unclear. On further examination, the study found that injuries occurred evenly throughout the
game, replicating a fmding of Seward et al. (1993), who also observed no significant difference in injury rate between the first and second half of the match.
5. 1 .4 Phase of Play
'Phase of play' refers to a particular strategic activity occurring within the course of a game and in rugby these include tackles, scrums, rucks/mauls, and lineouts. As shown in
Table 7, the tackle accounts for the highest proportion of general injury (38.7 - 55%) reported in rugby-related research.
Table 7.
Proportims of general injury idmtijiaJ in rugby inu:stigations as a rorzsequmce of dijfermt phases of play.
Phase D/Play (%)
Irm:stigations Tackle Scrums Rucks Mauls Linrout Other t
Sparks, 1985 39.6 11.9 18.7 6.9 1.4 21.5
Roux et al., 1987 55.0 8.0 18.0 1 .0 18.0
Dalley et al., 1992 38.7 6.2 10.3 15.2 2.1 27.5
Garraway & Macleod, 1995 49.0 8.0 15.0 2.0
Bird et al., 1998 40.0 7.0 17.0 12.0 24.0
t Includes phases of play not known, in addition to open play (Sparks, 1985), foul play (Roux et al., 1987) running, pile-up, kicking ball, up and under (Dalley et al., 1992) and back play (Bird et al., 1998)
Concussion is, as a consequence, also most likely to result from a tackle. Roux et al.
(1987) reported that 48% of concussions were associated with tackling, while Bird et al. (1998) revealed 64% of concussions were a consequence of this phase of play. Data obtained by the Rugby Injury and Performance Project (RIPP) showed that the
CHAPTER 5 PREVENTION
tackle situation, while concussion comprised 8% of all injuries sustained in this manner
(Wilson, Quarrie, Milburn, & Chalmers, 1999).
Most studies reported that rucks/mauls accounted for more injuries in general than the scrum (Dalley et al., 1992), with the safest phase of play appearing to be the lineout. Not shown in Table 7 are those injuries sustained through contact with another player. Dalley et al. (1992) reported that 75% of injuries incurred were as a result of player-to- player contact, while only 14% of injuries were received through contact with the ground.
5 . 1 .5 Position
The potential risk associated with specific player positions is a source of contention
for much of the research conducted in this area. Table 8 provides a review of
investigations identifying those positions in rugby union which feature the most and least risk of injmy.
Table 8.
Positions
in mgby uni.oo uhich areassociattd with the highest and Imrest risk of
inaming injury.Highest Risk Louest Risk