Abstract

Mechanical hand tools such as drills, rivet guns and jackhammers are inherently dangerous, as they can affect the neurological and musculoskeletal systems, causing such ailments as vibration syndrome or carpal tunnel syndrome. Since the causes and risk factors of these conditions are not well known, it appeared useful to examine some basic aspects of human motor control associated with the use of hand tools. This study was conducted to investigate the stabilizing function of the upper limbs in tool control, the existence of a link between grip force and static instability, and the effect of grip force on the hand’s rotational rigidity. The research results have a number of practical applications, including the design of handles that improve tool stability by maximizing the efficiency of the hand’s rotational rigidity. The concepts presented in this report can also be applied to other types of tools used in an array of settings such as slaughterhouses, textile plants and the assembly industry.