A South Island Brain Injury Research Group, led by the University of Otago's Dr Hamish Osborne and research fellow Dr Danielle Salmon, of the university's school of physical education and exercise sciences, undertook a study last year.
The study was carried out on Otago players in last season's Mitre 10 Cup. The tests involved a bluetooth sensor placed behind the ear of all the players in the five home games.
The sensor was about the size of a $2 coin and measured linear and rotational acceleration forces experienced by the head during impacts.
Salmon said, in a statement, the total number of impacts to the head sustained by players may be related to a large difference in strength between the left and right side of the neck.
``Those players who had larger differences sustained more impacts and impacts of greater severity,'' she said.
In what was not a great surprise, the impact data revealed props sustained the most frequent and strongest head accelerations forces while wingers had the fewest hits but those they did receive were often very powerful.
The analysis is ongoing and the next step was to use video to see exactly what was happening in the impacts between players.
Salmon could not be contacted yesterday for further comment.
