Figure 4From: Measurement of muscle length-related electromyography activity of the hip flexor muscles to determine individual muscle contributions to the hip flexion torqueConfirmation of the electrode positions. (a) Electrode positions on the hip flexor muscles. Representative maximal perimeter IL, 1 cm distal, and 1 cm proximal axial ultrasonographic images (b) and schematic illustrations (c) of the superficial region of the IL from under the groin at a hip joint angle of 0°. Representative axial magnetic resonance images with recumbent posture on the right side of the examination bed with the right hip joint set at -10°, 0°, 30°, and 60° (d). The electrode location on the IL is surrounded by a circle. L1, a straight line drawn along the posterior end line of the ilium on both sides; L2 and L3, two lines drawn vertically to L1 at the medial and lateral edges of the IL (Jiroumaru et al. 2014). FA, femoral artery; IL, iliopsoas; RF, rectus femoris; SA, sartorius; TFL, tensor fasciae latae.Back to article page