Kinematic and Kinetic Profile of Common Tasks for the Development of Design Parameters of an Upper Limb Prosthesis

PROBLEM STATEMENT:

Current improvements of the design of the upper limb prosthesis include advanced technology in control systems and electronic circuitry that mimic human motion and improve function of the prosthesis. Often times these improvements require large amounts of power, circuitry and excess mass distally along the prosthesis that may require greater effort from the user. Poor function of an upper limb prosthesis may cause awkward compensatory motion. Aberrant movements, such as these compensatory movements are known to cause greater stress to remaining joints. Amputees are forced to decide if the extra function provided by the advanced electronics is worth carrying the extra mass which may cause fatigue, socket issues and greater stress on the remaining joints. An example is the wrist rotator component of an upper limb prosthesis which may allow greater function and reduce compensatory motion, but adds mass distally, potentially causing greater torques on remaining joints.

SYNOPSIS OF CURRENT LITERATURE:

Restricted motion and excess weight of an upper limb prosthesis have been documented as complaints among amputees [1], [2], [3], [4], [5], [6]. Through surveys Atkins et al. determined that amputees would like the wrist component of the prosthesis to perform more movements. This study also listed drinking from a glass and opening a door, top priorities among amputees [7]. This suggests that the wrist component on a prosthetic arm is important.

There are many examples throughout scientific literature showing how kinetic, kinematic and metabolic analyses of gait have lead to the improvement of lower limb prosthetic design criteria [8],[9]. In 2003, Twiste et al. conducted a literature review on rotation and translation of the anatomic joints during prosthetic gait. The abstract from this review mentions that more accurate kinematic gait analysis showing optimized gait patterns could help manufacturers design prosthetic components to mimic these patterns [9]. The effects of mass perturbations on lower limb amputees have been investigated to determine how inertial properties of a prosthesis should be evaluated [10].