Shock wave traveling through the skeletal are more and more considered in the development of articular disorders. A method to quantify those skeletal transients is to estimate body segment linear accelerations. However, linear accelerations magnitude is influenced by many factors such as location and fixation of sensors, walking velocity, walking level and also by wearing conditions. Hence, experimental results in literature can't be easily compared and normative data haven't been established yet. The present paper proposes a method to estimate three-dimensional (3D) tibial and femoral linear accelerations during treadmill walking. 15 able-bodied subjects were evaluated. 3D kinematics data recorded from an optoelectronic system (Optotrak 3010, Northern Digital, Canada) at knee joint level were derived to estimated 3D linear accelerations of the tibia and the femur at their respective coordinate system origins.