International Society of Biomechanics in Sports (ISBS)
Abstract
With a squad of 27 players of an international standard team, we were able to compare torque-velocity curves of the backs (N=13), third line forwards (6) and first and second line forwards (N=8). A Biodex type dynamometer ( Biodex corportation Shirley, NY,USA) was used. On the basis of this torque data we can propose an explosive power factor consisting in the ratio: peak torque over time taken to reach peak torque. This can be calculated for any speed. This factor was computed for the group of rugby players and results for the different positions compared. It can be seen that the factor increases for the backs. Their maximum factor occurs at the highest speed. For the other towo groups the profile is identical : the highest factor is at the lowest speed. It should be noted that this value is more than twice that found for the backs. We also calculated the difference between eccentric and concentric torque and its relation with the type of players. For Schmidt Bleicher (1985) the explosive power subjects who make the most of their absolute (eccentric) force are those who show the smallest difference. Our findings show the forwards are the most effective according to this parameter. We completed our study by measuring jumping ability using squatting jump, countermovement jump and 15s Bosco powe rtest. The results will be discussed. A “Rugby-press” was used for monitoring specific strength of rugby players