Development of the Ergonomic Wrist Posture Range for Indonesian in Typing Activity Using Electromyograph

摘要

Carpal Tunnel Syndrome (CTS) is one of the most common neuropathies which occurs due to repetitive activity of hand using non-neutral wrist posture whether in flexion, extension, or ulnar and radial. Even though this posture may be inevitable, however it should be confined in maximum range. Thus, this is very significant to develop the allowable of maximum deviation of wrist. Objective of this study is to determine the maximum range of wrist postures in such four motions with evaluating the muscle contraction at wrist. A case study applied is to type a manuscript using computer. Experimental study was conducted by using electromyograph to identify Maximum Voluntary Contraction (MVC) on Flexor Digitorum Superficialis (FDS) and Abductor Pollicis Brevis (APB). Ten healthy university students (5 females, 5 males) were participated with age between 20 to 23 years old. The statistical analysis was conducted to test the hypothesis. Result of this study shows that the suggested maximum wrist posture range is not greater than 30° extension, 20° flexion, 20° ulnar, and 20° radial, although the neutral posture of 0° was highly suggested. This guideline is proven to be valid for both male and female.