The aim of this study was to establish muscle strength asymmetries of knee flexors and extensors depending on unilateral or bilateral muscle action among individuals in different sports (n = 260). The results show significant differences between unilateral and bilateral strength deficits for Tmax at knee flexion and also for RTD100 and RTD200 at knee extension and flexion. H/Q asymmetries show significant differences between unilateral and bilateral muscle action only on the right leg for RTD100 and RTD200. The proportion of individuals exceeding the different lateral asymmetry cutt-off values were significantly different for Tmax at knee flexion and for RTD100 at knee extension, and for H/Q cutt-off value 0,65 for RTD200 on the right leg. Additionaly, at least 32,7 % (extension) and 30 % (flexion) of individuals exceeds the clinically important 10 % lateral asymmetry cutt-off values independent of the muscle action for all three strength parameters (Tmax, RTD100, RTD200). Furthermore, 57,3 % – 73,8 % of individuals were below clinically important H/Q cutt-off value of 0,60 independent of the muscle action for all strength parameters.