Revised Leg prosthesis - Below the Knee

thingiverse

Based originally on an excellent design by Agung Dwi Junianto, Department of Industrial Design, ITS Surabaya, Indonesia, with guidance from Djoko Kuswanto, ST., M.Biotech. 10/15/18: Revised files are now available for a leg with all printed parts except the support post (1" OD aluminum) and hardware. All parts are printed in either PETG (leg socket), Carbon Fiber PETG, or CF Nylon to provide necessary strength and resilience. This new version is loosely based on an MIT design that utilizes a shorter foot with a small degree of flexibility, providing a much more natural gait when properly fitted. The foot should be given a sole of non-slip rubber so it can be worn either barefoot or inside of a shoe. Additional size-specific foot pads can be made to fit larger shoes if needed but the present design can accommodate a large number of sizes. This is an untested experimental design and should be treated as such. All tests I have accomplished indicate necessary strength and resilience are effectively present in well-printed parts, but real-world testing is needed to check viability. 2/15/19 As published, this is an immature design. There is no effective way to attach the device to a leg. Two variations are being worked on to accomplish this: one uses two-part polyurethane (quick set) and forms an accurate socket for the remaining limb using the patient's leg, wrapped in plastic and covered with mold release. The re-designed prosthetic will also incorporate an external knee brace from prosthetic to thigh. You must measure and adjust the socket end to fit the patient, leaving extra room for a prosthetic sock on the limb. Many considerations are involved when fitting a leg, so the health of both patient and remaining limb should be carefully assessed. Diabetics may have circulation problems, and any improperly healed or open lesions need to be fully healed before fitting. The remaining limb should show no swelling or inflammation. Finally, the construction materials of both foot pad and upper socket are critical to ensure needed strength of a 3D printed leg. I use a carbon fiber/nylon composite filament for the foot pad and PETG for the socket, both with high-density infill and multiple walls for strength. Any device should be tested thoroughly before fitting to assure maximum structural integrity. There are other possibilities for the device to limb attachment that you, as maker, need to determine will be best in your case. No matter what, your expertise in design, building, and fitting the device will all be tested.