DEVELOPMENT OF THE ERGONOMIC NECK POSTURE LEVEL BY USING ELECTROMYOGRAPHY METHOD

Abstract

Comfortable level of the neck posture on flexion and extension in working with visual display terminal (VDT) is an important position to alleviate neck discomfort. This paper presents a study to determine an appropriate range of flexion and extension to neck when working with VDT for Indonesian. Empirical study was conducted in ergonomic laboratory to identify those range levels. 70 subjects (35 males and 35 females) participated in this study. They were instructed to typewrite a document for 30 minutes on each position. Signal contraction on cervical erector spinae (CES) was recorded by using Electromyography and normalized into Maximum Voluntary Contraction (MVC) data. Statistical analysis was conducted to test the MVC difference between males and females. The study reveals that the maximum comfortable posture level is in the range of 30º below Ear-eyes Line (20%MVC) for flexion and 30º above Ear-eyes Line (17.42%MVC) for extension. This is proven to be valid for both males and females at 5% of significance level.