Investigation of Muscle Contraction on Motorcycle Handlebar Using Electromyography

A motorcycle is commonly used by people in Indonesia as a transportation device. It is because this device is flexible and affordable as well as easy to maneuver. However, the risk of driving a motorcycle is an emergence of the Carpal Tunnel Syndrome (CTS) on the wrist aside from the accident. This syndrome occurs when tissues surrounding the flexor tendons swell, providing pressure on the median nerve. It is caused by the vibration on the motorcycle handlebar that results from the engine and it will impair the muscle work. The objective of this study is to investigate the correlation between the Flexor Carpi Ulnaris muscle contraction and vibration occurred in the motorcycle handlebar and how much the muscle contraction comes about. An experimental study was conducted in an ergonomic laboratory in which six respondents have participated. Electromyography was used to identify Maximum Voluntary Contraction (MVC) on Flexor Carpi Ulnaris muscle which is functioned as controlling the throttle, clutch, and brake levers. Manual and automatic motorcycle with 110 and 125 machine capacity, and 1000 and 5000 speed level for a case study. Statistical analysis was conducted to test the hypothesis. The result of this study shows that the percentage of maximum voluntary contraction on flexor carpi ulnaris is higher on a manual motorcycle than the automatic motorcycle in 5000 rpm for 110 and 125 machine capacity, respectively, in which it will be higher as long as vibration increases on a motorcycle handlebar. An important finding of this study was that the machine capacity, the type of transmission, and the speed of engine will generate the vibration on hand’s muscle contraction. Thus, it is required to design the personal protective equipment to mitigate the affliction on hand for next study.