New plastic joints for plastic orthoses

Abstract

Plastic joints for orthoses have more advantages than metal joints. They are lightweight, noiseless comfortable to use, rust proof, corrosion free, and radiolucent. Two types of plastic joints were developed by the authors, one for the ankle joint and the other for the knee joint, elbow joint or hip joint. Polypropylene was chosen as the joint material because of its appropriate flexibility and toughness.

Physical sciences

“…73 In contrast to prosthetic applications, where components simulate the biomechanical behaviors of various muscle groups during different phases of gait, the challenge in orthotics is often to supplement the actions of existing joints and muscle groups. An early example of this concept was found in the 1982 publication of Watanabe et al 74 in which plastic joints were put forward as a lightweight, noiseless, rust proof, and corrosion-free alternative to the more common metal joints. More recently, the addition of an oil-damper to an AFO was proposed as a means of replicating the eccentric contraction of the dorsiflexors in loading response when these are insufficient.…”