Novel Use of Retro-reflective Paint to Capture 3D Kinematic Gait Data in Non-human Primates

Non-human primate models are extensively being used to study and understand biomechanical mechanisms of various neuro-motor pathological conditions such as Parkinson´s disease. However, collecting full body 3D kinematics using current technologies for obtaining reliable objective biomechanical measures to precisely characterize gait mechanics in non-cooperating primates is laborious and daunting task. We developed a method to reduce data collection and analyses time by using retro-reflective paint, a mixture of reflective powder and petroleum jelly that was applied directly on the primate´s skin. 3D kinematic data from three treadmill walking female rhesus primates (one normal and two MPTP treated) was collected using a four infrared camera system. Bilateral joint angle trajectories of hip, knee, ankle, shoulder and elbow for normal primate show 180 degrees out of phase. Step cycle duration and percentage stance are significantly different between the normal (F(9,62)=128.2) and MPTP (F(9,62)=143.1) treated primates. Step cycle duration between forelimb and hindlimb is not significantly different in all primates. However, percentage stance in less affected limbs of both MPTP treated primates is significantly higher in forelimb than hindlimb. Gait pattern of normal primate is diagonal symmetrical gait, one MPTP treated primate showed lateral symmetrical gait and other showed a non-standard gait pattern.