 Trauma is the second most common factor for transtibial amputations, just after vascular background. Traumatic amputees generally function better than amputees due to vascular background. The type of prosthetic foot fitted to the patient depends on his mobility and functional level, and significantly influences his stability and gait symmetry. A prosthetic foot with a hydraulic ankle provides significant advantages for high level functioning amputees: decrease of loads in the residuum, improvement in symmetry and generally gait pattern that is closer to natural. The hydraulic prosthetic foot has recently been upgraded to include computerized control over the ankle movement, using input from an array of sensors inside the foot. Studies have demonstrated decrease in energy consumption and gait pattern that is more similar to healthy people. However, hydraulic feet with and without computer control have not been compared. Furthermore, the effects of a computerized foot on various important factors have not been investigated yet, e.g. loads in the residuum, the movement of the center of pressure and the patients satisfaction. 