39 reflective markers were placed on the subjects’ bodies.
Most of the markers were placed on the anatomical landmarks
of the caregivers along with the rest to form the rigid bodies to
track: head, left and right upper arms, left and right forearms,
left and right hands, upper trunk, pelvis, left and right thighs,
left and right shanks, left and right feet. Thus A 3D full body
model with 15 segments was constructed.