Objective To provide unique descriptive information on head accelerations, both linear and rotational, during ‘bodies in front’ training play.

Design A convenience sample were tested using a cross-sectional design. Players wore a triaxial accelerometer (XPatch, X2 Biosystems, Seattle) during two sessions of training gameplay (session duration 142±26 min). Accelerometers were affixed on the left side of the head, at a point approximate to the external occipital protuberance.

Setting Testing was undertaken at an elite performance training centre.

Participants 20 elite, professional, rugby league players.

Main outcome measures Minimum recordable accelerations were set at 10 g (linear acceleration) and 25 rads s^-2 (rotational acceleration).

Results A total of 1256 recorded ‘hits’ were analysed, excluding evident artefacts. No player was reported to have suffered a concussion. Player ‘loading’ was 46±33 hits per session (range 7–170). Average linear (14.9±8.8 g) and rotational (532±347 rads s^-2) accelerations were not significantly different between training sessions (P>0.05). Frequency of hits are summarised in the table below.

Conclusions The majority of head accelerations occurred within lower ‘sub-concussive’ zones. This confirms existing research findings from other sports. Whilst few accelerations occurred in higher zones, there were a number of very high loading impacts observed in ‘hit up forward’ positions. Our research confirms the suitability of using portable accelerometers in determining head accelerations in full-contact, ‘armourless’, invasion games.

Competing interests None.