Spring Mechanisms in the Foot and Lower Extremity In this 18-minute mini-lecture, I review how the spring mechanisms within the foot and lower extremity are vital to optimizing the biomechanics of weightbearing activities. Hooke's Law is reviewed along with the concepts of spring stiffness, viscoelasticity, and how running, galloping, and hopping animals all use elastic strain energy stored within their muscle, tendons and ligaments in order to improve the metabolic efficiency, speed, power and