To help walking,using assistive devices can be considered to reduce the loads caused by weight and to effectively decrease the propulsive forces.In this study,a mobility Saddle-Assistive Device (S-AD) supporting body weight while walking was evaluated on two healthy volunteers.This device is based on the support of body weight against gravity with the help of a saddle,which is not used in other passive mobility assistive devices.To prove the efficiency of this device,the experimental results obtained while walking with this device were compared with those related to walking without the assistive device.The results showed that this device could significantly reduce the forces and torque of the lower and upper limbs when walking.By distributing the load on the saddle,the vertical force and the propulsive force in the best conditions were decreased to 46.7％ and were increased to 13.7％ in body weight,respectively.Using a S-AD can help patients with lower limbs weakness and elderly people to walk.