In the past, muscular strength has primarily been measured using isometric, isotonic or tensiometric techniques. The advent of isokinetic dynamometers has supplied an objective method of measuring peak torque throughout a full range of motion at a predetermined speed of contraction. An isokinetic contraction is a refinement of the controlled motion concept. The isokinetic contraction is dynamic, but the speed of the motion is held constant by a special device. In this way, resistance is in direct ratio to the varying force applied through the full course of a natural movement. The purpose of this study was to determine the peak torque of quadriceps (Q), and hamstrings (H), and their biomechanical angle of production, H to Q ratio and bilateral comparisons of these variables for the first time in a Southamerican population. Twenty healthy and voluntary males (age: 21.9 +/- 3.1 years, height 193.2 +/- 6.5 cm, weight: 84.2 +/- 5.2 kgs.), were tested on the Cybex II Dynamometer and Cybex Data Reduction Computer (CDRC). Quadriceps and hamstrings peak torque (pkTQ), in Newton-meters, were obtained at angular velocities of 60, 180 and 240 degrees. sec-1. Also, the angle of the range of motion at which peak torque occurred in both directions, H and Q peak torque to body weight ratios, H to Q ratio were measured. Finally, CDRC provided the bilateral comparison of the different variables expressed in percentages. All measurements were automatically corrected for the effect of gravity. The absolute maximal pkTQ of dominant (D), and non-dominant (ND), quadriceps at 60 degrees/sec was DQ 297 +/- 25 Nwm and nDQ 303 +/- 13 Nwm.(ABSTRACT TRUNCATED AT 250 WORDS)