Micro motion analysis of the human arm, performing with a body powered hook

The study was designed to investigate the performance of amputees by means of a micro motion and time technique. The objectives of the investigation were to analyze the basic motion elements that construct the locomotion of the amputated arm while performing a manipulative task, to relate and compare the motions of a work cycle between amputated and natural arms for the same task, and to investigate qualitatively and quantitatively the contribution of each motion element to overall performance. Based on the results of this investigation, the researcher was able to point out which part of the motion should be considered for improving time performance of the body powered mechanical hook used by amputees. Twenty-six subjects participated in this experiment, half of whom were amputees and the other half non-amputees. The study utilized the Methods Time Measurement (MTM) technique - a widely used industrial engineering procedure - as an evaluative method. The findings showed significant differences in both motion and time elements between the performance of amputees and non-amputees - mainly due to the motion element grasp. Outlines for improvement of the design of the hook on the basis of this study are discussed.