Muscle Activity and Comfort Perception on Neck, Shoulder, and Forearm While Using a Tablet Computer at Various Tilt Angles

Abstract

Tablet computers have become ubiquitous. There is a serious risk that using tablets may lead to musculoskeletal disorders. This research aims to investigate, for tablet computer users, the musculature load and comfort perception of the engaged upper extremity for three angles of viewing and common task types performed at a computer workstation. Thirty healthy adults were recruited. A 3 × 2 repeated experimental design with tilt angle (22.5°, 45°, and 67.5° from horizontal) and task type (movie watching vs. game playing) was employed. The muscular activity of the upper extremity was assessed by electromyography measurement. Subjective comfort ratings were collected using the visual analogue scale. The results showed that when tablets were mounted at a high tilt angle (67.5°), neck muscle activity was low; however, when the tablet computer was mounted at a low tilt angle (22.5°), shoulder forward flexion activity was low, particularly during the game-playing task. This article suggests that users who feel musculoskeletal discomfort in the neck area increase the angle of their tablet computers to decrease neck stress and that users who have musculoskeletal discomfort in the shoulder area position the tablet computer at a lower tilt angle to decrease shoulder stress.

Additional information

Notes on contributors

Hsiao-Ping Chiu

Hsiao-Ping Chiu is the Vice General Manager of Foxconn Information Ergonomics Center, Taipei, Taiwan. She graduated with a Ph.D. from the Department of Industrial Engineering of National Chiao Tung University. Her research focuses on usability testing of computer and smartphone devices.

Chia-Nai Tu

Chia-Nai Tu is the fellow of Foxconn Information Ergonomics Center, Taipei, Taiwan. He graduated with a master’s degree from the Department of Industrial Engineering at National Chiao Tung University. His research focuses on usability testing of computer and smartphone devices.

Shu-Kai Wu

Shu-Kai Wu is the fellow of Foxconn Information Ergonomics Center, Taipei, Taiwan. She graduated with a Ph.D. from the Department of Industrial Engineering at National Taiwan University of Science and Technology. Her research focuses on usability testing of computer and smartphone devices.

Liu Chien-Hsiou

Liu Chien-Hsiou is associate professor in the Department of Occupational Therapy at Fu Jen Catholic University, Taipei, Taiwan. She graduated with a Ph.D. from the Department of Industrial Engineering of National Chiao Tung University. Her research focuses on usability testing of computer and smartphone devices.