Trunk motions in three planes. In each graph, the transverse axis represents the phase of the gait cycle as percentages of gait cycle and the vertical axis represents angular values. The graphs depict trunk motion in each plane using global and pelvic reference frames. Relative phase of motions between two reference frames were almost reciprocal in the sagittal plane, synchronous in the coronal plane, and 15% different phase in the transverse plane. Note two repetitive motions in tilt (G) and tilt (P), and the slight differences between maxima (asterisks) and minima (arrow heads) during first and second motions, which are believed to be influenced by motions of other planes. The bars on the transverse axis represent double limb support phases.