RESUMO
BACKGROUND: The alignment of the lower limb prosthesis is an integral part of the prosthetic fitting. A properly aligned prosthesis contributes to optimal gait and overall function of the patient. The current offering of alignment componentry is expensive for low-income countries. The purpose of this study was to develop a lightweight and low-cost alignment coupler for the lower limb prosthesis. METHODS: An alignment coupler called the reversible adjustable coupling was designed and manufactured. Measurements of total anterior/posterior and medial/lateral and rotation in prostheses were recorded and mechanical testing performed. Swiftness and difficulty of use was also recorded. RESULTS: The reversible adjustable coupling permitted acceptable ranges of anterior/posterior and medial/lateral translation and 30° of internal and external rotation of prosthetic componentry. Repetitive loading of the coupling at a speed of 1 Hz under 1.28 kN load for 2000 cycles was successful, as were static and strength tests. DISCUSSION: The coupler provided acceptable ranges of anterior/posterior and medial/lateral and rotation adjustment and is acceptable for potential use in the alignment of both exoskeletal and endoskeletal prosthesis. The final weight of the component was 166 g and cost of $55.00 USD is affordable for low-income countries for use in clinical and educational settings.
RESUMO
BACKGROUND: Durable and locally fabricated prosthetic feet are important for developing countries. Modifications to the current CR solid ankle-cushion heel prosthetic foot could enhance current foot characteristics and reduce costs. The goal of this project was to modify the keel and rubber outer foot shell to enhance features and reduce costs of the current CR solid ankle-cushion heel offering. METHODS: The prosthetic foot was designed, fabricated and then tested mechanically for strain and displacement in a cyclic testing machine according to a component of the ISO-10328 testing protocol. Dynamic cyclic testing of both forefoot and heel portions of the foot was conducted. FINDINGS: Dynamic mechanical cyclic testing of the forefoot and heel at 1.28 kN for two million cycles at a rate of 1 Hz was successfully achieved. The final cost of producing the foot was roughly $16 USD. Limitations include the inability to perform the full battery of ISO-10328 foot testing, UV testing and a limitation to laboratory testing. Clinical studies examining practical application of the modified foot should be conducted.
