To determine whether the canine pelvic limb can be considered a linkage of rigid bodies during kinematic analysis.
The lengths of the femur and tibia based on skin markers were examined throughout gait cycles in six dogs trotting on a treadmill at 2 m/sec. The angular kinematics of the hip, stifle and tarsal joints were calculated based on a conventional stifle marker (CSM) and computed virtual stifle positions (VSP). Based on the CSM and VSP, the kinematic data from the joints were compared and the agreement among them determined. The difference between the CSM and VSP coordinates were illustrated.
The femoral and tibial lengths based on skin markers were not constant throughout a gait cycle and the lengths changed in repeatable patterns in each dog. There was close agreement between the joint angles based on the CSM and VSP in the tarsal joint but not in the hip and stifle joints, where the kinematics based on the CSM tended to calculate smaller angular excursion than the kinematics based on VSP. The pattern of displacement of the CSM was repeatable through a gait cycle.
There was skin movement which causes considerable artifact during kinematic analysis of the canine pelvic limb. The skin movement has to be accounted for during canine kinematic analysis.