Normal isometric and isokinetic peak torques of hamstring and quadriceps muscles in young adult Saudi males

OBJECTIVE: To provide reference data for peak isometric and isokinetic muscle strength of hamstring and quadriceps muscles in young adult Saudi males.

METHODS: The strength of left and right quadriceps and hamstrings leg muscles was assessed in 132 college-male students in the campus of King Saud University, Riyadh, Kingdom of Saudi Arabia in the year 2002 using a Cybex machine and a standardized protocol at the following velocities: 0, 60, 180, and 300 degrees/sec. Isometric strength (0 degrees/sec) was assessed at 65 degrees angle of knee flexion.

RESULTS: Isometric flexion strength was 9.3% higher in the right leg compared to the left (p < 0.01), while there was no significant difference between the 2 legs in extension. In isokinetic strength, there was a decrease in both extension and flexion strength with increasing velocity. However, only in flexion strength a significant right-left difference was observed. Flexion/extension peak concentric torque ratio relative to angular velocity varied from 59.9-63.3% in the right leg and from 55.8-59.9% in the left leg, with significant difference (p < 0.02) between the 2 legs. In addition, the angle of peak torque decreased with increasing velocity at knee extension but increased at knee flexion.

CONCLUSION: Young Saudi males appeared to have similar isometric peak strength in the knee extensors but not in the flexors when compared to previously published research. Isokinetic extension strength at 60 degrees/sec in the Saudi males is lower than values reported for untrained males elsewhere. Furthermore, the hamstrings/quadriceps ratio in Saudi males seems to be within the recommended range of appropriate muscle function.