Effect of Ergonomic Design Changes in Hand Tools on Physiological Cost and Subjective Ratings

Abstract

Users of hand tools expect that tools after ergonomic changes in design will require less muscular activity and cause fewer musculoskeletal disorders than conventional tools. Reports on evaluation of ergonomic design changes in hand tools are controversial. In this study, we measured the effect of changes in tool design with physiological cost of performance and subjective ratings in a simulated setting. We determined physiological cost of performance by measuring muscle activity of the right and left forearm (flexor carpi ulnaris) with electromyography. We collected a questionnaire with subjective ratings before and after each experimental task. Before the tests, ergonomically reconfigured hacksaws received better rating scores than original hacksaws. However, we found no differences in subjective ratings of the hacksaws after the tests. In addition, electromyographic activity did not show any significant differences between the original and modified tools.

Identification of Grip Profile for Hand Tool – A Preliminary Ergonomics Study

“…Handles were also should be slip-resistant, either by material or by design. Designing hand tool was a complex tasks as it requirement considering not only functionality, quality, and reliability, but also their uses expectations and apprehensions (Kim, 2012).…”

“…The appearance and design of tool is influenced by the human body, the materials available, and the tasks to be performed. Improvements in ergonomics characteristics of hand tools may be essential to reduce the risk of musculoskeletal disorders, as ergonomically designed hand tools cause users less harm, require less effort, and provide more comfort at work (Kim., 2012). A tool becomes "ergonomic" only when it fits the task and hand without causing awkward postures, harmful contact pressures, or other safety and health risks while performing works.…”