and, importantly, to assist in monitoring the rate of recovery from TBI. Assessment
measures are typically selected on the basis of their sensitivity to assess areas of functioning
0iAPTER 6 PROPOSED RESEARGI
affected by MmI and on the availability of multiple equivalent fonns, to ensure that the monitoring of an individual's recovery to baseline levels is reliable. Despite some
developments, research in this area remains relatively new, with more exploration required to establish measures appropriate for use in a sporting context.
Risk factors associated with MfBI in rugby union are somewhat equivocal with respect to age, experience, and the individual positions held by players. However, it is widely accepted that players occupying forward positions in general, are more at risk of injury than those in the backs, and that in contrast with other phases of play, involvement in tackles place a player at greater risk. With respect to the prevention of MmI in sport, the focus has been on regulation changes, improving coaching techniques, use of protective equipment, and improving the overall conditioning of the athlete.
6.2 FORMULATION OF PROPOSED RESEARCH - PHASE I
Phase I of the research was designed to investigate a number of different areas associated with MmI in club rugby, employing the use of three questionnaires (the RPQ, HMQ and AMQ, discussed later in Chapter 7) to address the following objectives.
6.2.1 Rate of Brain Injury and Relationship to Other Injury
A review of the available literature revealed that the investigation of rugby-related injury at the club grade level had received little attention compared to studies involving school and elite/professional rugby players. Additionally, these studies typically focused on a broad range of injury, as opposed to a more concentrated inquiry of Mm!. Therefore, a primary objective of this research was to investigate the rate of MmI sustained by players
0iAPTER. 6 PROPOSED RESEARGI
at club level, allowing for comparisons with pre-existing rates evidenced in rugby in addition to more crude comparisons with rates in other collision sports.
Another objective associated with determining the incidence of MTBI was to identify the rate of repeat brain injury, to establish whether players with a history of MTBI were more at risk of incurring future brain injury than those with no prior history. As previous research has indicated that delayed reaction times and poor decision making associated with brain injury may predispose an athlete to an increased risk of general injury (Ingersol1,
1983; Gronwall, 1989), it was the intention of the present study to identify whether this phenomenon was evident in this particular population. Establishing the rate of non-MTBI related injury would also provide a basis for presenting a MTBI rate, enabling comparison with previous studies.
6.2.2 Severity of Brain Injury
As a consequence of the biomechanical forces associated with sport-related TBI and in conjunction with previous reports of severity in the literature, it was anticipated that the brain injuries sustained in club grade rugby would constitute injuries at the mild end of the spectrum (i.e., MTBI or concussion). As different classifications of severity exist for such injuries (as indicated by concussion severity guidelines) which warrant different
management, it was considered important to establish the severity of concussion
experienced at this level. Once established, this would allow for comparisons to be made with elite/professional and school grade rugby teams.
On the basis of the retrospective nature of the questionnaire and the lack of
corroborating evidence, establishing the reliability of respondents' reports of concussion severity was expected to be difficult. Severity of a MTBI was therefore to be determined in one of three ways:
(1)
by the number of symptoms endorsed; (2) by reports of a LOC; or (3) by reports of diagnosis by respondents. In the absence of information pertaining to0iAPTER 6 PROPOSED RESEARaI
duration of PTA, the munber of symptoms experienced by a respondent was considered of value in indicating the severity of a concussion. In accordance with Roberts'
(1992)
criteria, the recall of only dizziness and/or headache in the absence of a LOC or a
diagnosis of concussion was to be considered indicative of a vtrymild concussion - a bell-
ringer (refer Table
9).
While a somewhat arbitrary division, the recall of at least three or more symptoms (excluding LOC) was to be classified as amild
concussion, while injurieswith only one or two symptoms (excluding headache and/or dizziness) would fall into a
my
mild
-mild
severity category, as shown in Table9.
The latter division was formed onthe basis that the presence of a symptom such as memory impairment 3 would likely be
indicative of more severe injury than the presence of headache or dizziness alone. In accordance with Cantu's
(1986)
guidelines, a moderate concussion is indicated by a LOC, aphenomenon more likely to be recalled by the player than the subtle symptoms of MfBI.
Therefore, in the present study a LOC would be considered a definitive indicator of a
rrrxlerate
severity injury.Table