A low-cost prosthetic foot for jumping, running, and walking on terrains is proposed.  A scientific approach is used which includes analysing the foot biomechanics of unilateral transtibial amputees, characterising the relevant materials, designing a leaf spring system, and examining the 3D geometrical changes and biomechanical parameters of the knee while in motion, and skin-prosthesis interface pressure and thermal response to the anatomical design of a protective liner.