As documented for the head, dynamic posturing of the trunk appears to be actively controlled
during normal locomotion. Over the stride cycle the trunk is mildly bent forward as
compared to upright standing, and during single-limb support it moves further forward and
toward the weight-bearing limb, with a side-shift initiated prior to the ground contact and
mainly produced during the double-support phase (Thorstensson et al. 1984, Krebs et al.