Fig. 1From: Effects of age and physical activity on response speed in knee flexor and extensor musclesMean values for normalized response speed (V rn) expressed in millimeter per second, at a 95 % confidence interval (95 % CI) and σ (standard error of mean), for the right vastus lateralis muscle (VL) for each of the study groups (p ≤ 0.05)Back to article page