Comparison of force and peak EMG during a maximal voluntary isometric contraction at selected angles in the range of motion for knee extension.

For 5 adults maximal isometric strength at 110 degrees, 90 degrees, 70 degrees, 50 degrees, and 30 degrees of knee flexion for the vastus medialis, rectus femoris, and vastus lateralis varied across angles but EMG responses were similar. That motor recruitment patterns were similar throughout the range of joint motion requires replication on a larger sample.