Background During a tackle 1997 Newtons of force (equivalent to 204kg) is known to be transmitted to an opponent, however there is currently no known minimal force threshold leading to concussion. Amongst the other factors considered, contact technique has been identified as a potential injury cause, with head position proposed as a key variable.

Objective To investigate whether cervical proprioception is significantly associated with concussion incidence in a group of male professional rugby players.

Design Prospective cohort study.

Setting 165 professional rugby players across 12 Rugby Union teams and three professional leagues were assessed, during the 2018–2019 season.

Interventions Athletes were assessed for cervical proprioception at three time points throughout the season using the Joint Position Error Test.

Main Outcome Measurements Associations with diagnosed concussion injuries are presented as Incidence Rate Ratios (IRR) with 95% confidence intervals. we present the IRR for a 10% increase in each variableand compared results against concussion using match minutes to allow for risk exposure.

Results During the study period, 45 concussions were incurred by 44 players giving a rate of 19.7 concussions per 1000 player-match hours. There was a significant association between right rotation repositioning error and concussion with a 5% increase in concussion risk for each 10% increase in gross right rotation error (P=0.021) and a 6% increase in concussion risk for each 10% increase in right rotation along the horizontal plane (P=0.0001).

Conclusions Using the JPET for cervical proprioception it is possible to highlight rugby players who are at greater risk of concussion. The JPET is a fast and cheap test to set up and does not require specialist equipment.