As elderly society progresses, development of machines for assisting human to walk is getting more important nowadays. We develop cart-type machines to assist walking of the user. In this paper, we have evaluated a human walk using the cart which was developed for this research. We estimated the energy consumption based on the muscle-skeleton model. It is shown that the energy consumption using the cart has decreased by 6% of the normal gait. Our evaluation method will be useful for developing a walker for practical purposes.