Analysis of Electromyography on Computer Interaction Devices to the Risk of Carpal Tunnel Syndrome Hartomo Soewardi, Annisa Riska Anugraheni * , Nella Shabrina Industrial Engineering Department, Faculty of Industrial Technology, Islamic University of Indonesia, Yogyakarta, Indonesia. * Corresponding author. Tel.: +62 8562883376; email: annisa.rizkaa@gmail.com Manuscript submitted March 5, 2015; accepted July 25, 2015. doi: 10.17706/jcp.10.5.347-353 Abstract: Use of interaction devices on human-computer system may cause muscolusceletal disorders. This paper presents an Electromyography study to evaluate the hand muscle activities when it is interacted with the computer using mouse, keyboard and joystick. These muscles investigated are flexor pollicis brevis, flexor digitorium superficiallis and abductor pollicis brevis. Average of Root Mean Square (mRMS) signal was used as parameter. Experimental study was conducted where 8 females and 7 males were participated to complete virtual task for 15 minutes. Virtual manufacturing robots system was used as a case study. Non parametric statistical method was conducted to test the hypothesis. The result of this study shows that the highest risk of carpal tunnel syndrome was found in the joystick on flexor pollicis brevis muscle and abductor pollicis brevis muscle. Meanwhile on flexor digitorium superficiallis muscle contraction was found in the keyboard devices. Thus, use of mouse is better. Key words: Electromyography, input devices, mRMS, CTS. 1. Background In Indonesia, the percentage of Personal Computer (PC) users in 2010 to 2012 years are 7.45%, 6.89% and 6.46%. Inversely, use of laptops/netbooks have increased from year to year that are 6,44% in 2010, 8.80% in 2011 and 12.19% in 2012 [1]. Ref. [2] mentions that accessing a game by using laptop takes longer time than others, which is 8% of users play a game less than 1 hr/day and 8.7% play a game more than 16 hr/day with an average period of the players are 2-8 hr/day. However, use of computer/laptop can lead to increase some health problems such as musculoskeletal disorders, eye fatigue and overuse injuries on the shoulder, arm, hand and wrist [3], [4]. Furthermore [5] & [6] expressed that computer devices such as keyboard, mouse and joystick also cause a risk in developing musculoskeletal symptoms especially at hand. Carpal tunnel syndrome (CTS) was a symptom commonly that is reported in computer professionals. Where CTS is a syndrome that occurs because compression of median nerve in the carpal tunnel on wrist area when the nerve passes through a tunnel from the forearm to the hand [7]. It is caused by repetitive hand motion especially in persons whose work inquires repeated forceful finger and wrist while flexion and extension [5]. A survey on computer users indentified that 29.6% user experience hand paraesthesia syndrom and 10.5% user have CTS [8].