The walking training system 1 includes an upper marker 52 and a lower marker 54 installed at locations on the walking assistance apparatus 2 spaced apart from each other in a leg length direction. The control apparatus 100 calculates accelerations of the two markers using images taken by the camera 10, and estimates an acceleration at the center of gravity of the walking assistance apparatus 2 from accelerations of the two markers. The control apparatus 100 then calculates an inertia force acting on the walking assistance apparatus 2 from the product of the acceleration at the center of gravity and the weight of the walking assistance apparatus 2. The control apparatus 100 controls the forward pulling unit 35 and the backward pulling unit 37 to reduce the inertia force acting on the walking assistance apparatus 2.
