<i>A 2D Stick Model for Simulation of Sow walking</i>

A 2D stick model was developed to simulate sow walking. The model consisted of thirteen landmarks to form a simple stick figure that approximates sow body. The video images of sows with reflective markers on the body walking along a corridor were analyzed and translated into a 2D coordinate data sets. The motion of each landmark, including displacement, velocity and acceleration were calculated. A step of walking, including a foot leaving the ground, swinging, and touching the ground are divided into three categories of movement, that is, acceleration, constant speed and deceleration. Foot displacement was described by a 2nd order polynomial function. The coordinates of all connective body joints (landmarks) were then linked through the motion of each marker. The model was intended to be used to assess the walking behaviour of sows to help detect lameness.