Abstract
This study investigated the relationship between thumb muscle activity and thumb operating tasks on a smartphone touchscreen in elderly users (right hand posture). Three thumb muscles were targeted in the experiment, namely, abductor pollicis brevis, abductor pollicis longus (APL) and first dorsal interosseous (FDI). The results showed that the elderly participants developed fatigue rapidly and tapped more slowly when operating on smaller buttons (diameter 3.0 mm compared with 9.0 mm) and moving in the flexion–extension (compared with adduction–abduction) orientation. Meanwhile, electromyography and perceived exertion evaluation revealed significant increases in FDI in the small button task, and results for APL were significantly greater in the flexion–extension task. This study suggests that the use of small touch-buttons and flexion–extension movement should be minimised in the handheld touchscreen interface design for elderly users.
Highlights
As one of the fastest growing technologies in modern times, the astonishing growth of phone-owning population seems to be continuing for all age groups and regions around the world, irrespective of the economic disparities (Boretos 2007)
Compared to the larger button task, the rating of first dorsal interosseous (FDI) was significantly higher in the small button task (Fig. 3)
The contraction time and iEMG of FDI significantly increased from the small button task to the large button task, but no statistically suggestive variations were detected in the other two muscles (Table 3)
Summary
As one of the fastest growing technologies in modern times, the astonishing growth of phone-owning population seems to be continuing for all age groups and regions around the world, irrespective of the economic disparities (Boretos 2007). In order to enhance the ability to recognise touch targets, many elderly users may prefer to set the fonts and icons to a larger size. This could increase the time that they require to flip through the menus, and their thumbs (when operating with one hand) have to pass over a larger area to reach the larger targets. A study found that small touch button size, poor spacing among the touch buttons and inconvenient location of targets on touchscreen smartphones significantly reduced the finger pointing performance in elderly users (Hwangbo et al 2013). Cole and Rotella (2002) reported that aging is a significant factor that impairs visual cues for predictive control of finger force when gripping a mobile phone in hand. Olafsdottir et al (2007) pointed out that decreased performance in accurate multi-finger
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
