The effect of vibration on muscle activity using electric drill

Vibration seems to be the most critical Ergonomics Risk Factors (ERF) in Malaysian industries. In order to quantify and determine the safe levels of human exposure to vibration, measurements and analysis of vibrations are therefore necessary. The aim of the study is to identify the effect of hand-held vibrating tools on significant muscles. The study was conducted on seven subjects (three male and four female). The experiments were performed with two kinds of exposure time: 5 and 15 minutes. Subjects were required to drill wood material using electric drill. Electromyography (EMG) and Vernier Labpro with 3 axis accelerometer used in the experiment. The mean vibration level for electric drill was 10.53 m/s2 for 5 minutes and 10.39 m/s2 for 15 minutes duration. The most affected muscle due to vibration was found to be the extensor Carpi radials muscle. Extensor Carpi radials is one of the muscle at the forearm. Drilling wood material in 5 minutes give higher vibration level and %MVC than 15 minutes. The results in the study indicated that as the level of vibration increases the muscular activity is also increases and thus can be concluded as a contributory factor to arm disorders such as muscle fatigue among power hand tool operators.