KNEE MUSCLE STRENGTH IN ELITE MALE GYMNASTS

This study was launched to establish the profile of knee dynamic conce ntric strength in elite male gymnasts after ii was found that three of the 10-member Canadian men's gymnastics team had incurred anterior cr uciate ligament (ACL) rupture. The dynamic concentric force characteri stics of the quadriceps and hamstring muscles of 84 male gymnasts were studied at the Canadian National Championships using a Kin-Com isokin etic dynamometer. These tests were performed at 90 degrees/sec and 230 degrees/sec and revealed that the hamstrings to quadriceps peak torqu e ratio was not only unusually low (0.5) when compared with data colle cted in previous research, but that this ratio was consistent across a ll ages, from 12 to 27 years. The torque ratios were also reported at 30 degrees, 45 degrees, and 60 degrees and it was found that the ratio s decreased as the joint angle increased and again was consistent acro ss the four age groups. It was also found that the hamstrings to quadr iceps peak torque ratio did not increase (hamstrings becoming stronger relative to quadriceps) as velocity of movement increased as has been reported in other studies. It was hypothesized that the large shear f orces that are generated about the knee in gymnastics (extrinsically f rom backward landing and intrinsically from the quadriceps eccentrical ly contracting), combined with the relatively weak hamstrings, could b e one cause for the increasing incidence of ACL injuries in that sport The results of this study indicate that it would be prudent for clini cians involved with gymnasts to test for knee strength imbalance and t o prescribe exercises to correct it when necessary.