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Rugby Injury Prevention

The Rugby World Cup is here again. On location, or in front of their TV sets, supporters the world over are encouraging their favorite players, a much less dangerous exercise than that of the professionals–particularly during scrummaging where enormous forces are exerted between the eight players from each team. To measure rugby players' skills, researchers from the Biomechanics and Biomedical Engineering laboratory1 in Compiègne, have designed a specific device called the Rugbor v2 ergometer.
This ergometer, equipped with force sensors linked to a computer, provides a support surface for the shoulders while the player's head fits through a central cage. Front- row players from the Junior French team (under 19) used Rugbor to simulate engagements with impact according to the rules of the International Rugby Board (IRB)–the institution that governs world rugby. The results were edifying: “For 0.2 of a second, we measured a mean engagement impact force between 3000 and 7000 newtons (N)–the equivalent of a mass of 300-700 kg. The maximum impact force could even reach 12,000 N,” says Didier Gamet. “And while driving forward after impact, less effort is required (1500 to 4000 N), but it has to be sustained.”
From a sports perspective, a scrum is highly strategic: it enables a team to gain ascendancy over its opponents. But its practice is not without risk for the neck muscles. After impact, the player drives forward and also raises his head to “destabilize the opponents,” a move that requires approximately 300 to 500 N. This is equivalent to lifting a bag of cement up to 30 times during a match (the average number of scrums in each game). Players also risk premature spinal wear and, when the scrum collapses, cervical trauma which can be severe enough to compromise spinal cord function.
The French Rugby Federation aims to reduce the risk of cervical injuries, and always ensures that its front-row players undergo X-ray exams. For this purpose, it set up the Rugbor apparatus at its national training centre in Marcoussis. Early results on 67 male and female players are both informative and useful for prevention. They allow force kinetics to be described during scrummaging, differences in maximal impact, push and head extension forces with respect to the player level, the attributed post and the gender, as well as potentially high risk positions. The same researchers are also working on a third version of the system, supplemented by a robot capable of reacting to drive forwards.

Gaël Hautemulle

Notes :

1. Laboratoire de biomécanique et de génie biomedical (CNRS / Université de technologie de Compiègne). The ergometer has been developed in partnership with the Laboratoire Roberval de mécanique in the same university.

Contacts :

Didier Gamet,
Laboratoire de biomécanique et de génie biomédical, Compiègne.


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