Design and Validation of a Prosthetic Foot Adaptable to Sagittal Plane Ground Irregularity

Amputation involves the removal of a limb or part of it. In the case of the lower extremity, amputation affects the ankle joint and the metatarsophalangeal and intertarsal joints, improving the foot's adaptability on uneven terrain. Therefore, based on state-of-the-art technology that does not address the other joints of the foot to a large extent, a prosthetic foot has been developed that integrates the support structure of the foot through a foot arch with an extension analogous to the forefoot and an elastic element that mimics the plantar fascia that deforms against obstacles and provides stability to the prosthetic arch foot. The work addresses the design of the prosthetic foot from its design to its prototyping and validation, where the foot was shown to withstand the loads recommended for the P5 category of the ISO 22675 standard and to provide a return energy equal to 95.72%, 77.13%, and 90.21 %, in the heel strike, mid-stance, and toe-off stages, respectively. In addition to showing linear stiffness properties (66.95 kN /m) and torsional stiffness properties(2.05 kN.m/rad) in the forefoot analog element, values that are comparable with those recorded in commercial tests such as LP Variflex categories 7 and 8.