Fig. 2

The thicknesses of the left (Fig. 2 A) and right (Fig. 2B) multifidus in the resting (blue line) and contracted conditions (red line). Comparison of the thicknesses in the resting (blue column) and contracted conditions (red column). Group 1 is right, and group 2 is left (Fig. 2 C). The sonogram of the multifidus: left shows the relaxed state, and right shows the contracted state (Fig. 2D)