TY - JOUR
T1 - Influence of virtual keyboard design and usage posture on typing performance and muscle activity during tablet interaction
AU - Lin, Ming I.Brandon
AU - Hong, Ruei Hong
AU - Huang, Yu Ping
N1 - Funding Information:
This study was funded by the Ministry of Science and Technology of Taiwan [100-2221-E-006-198]. The authors thank Xin-Min Ke for his help with data collection.
Publisher Copyright:
© 2020 Informa UK Limited, trading as Taylor & Francis Group.
PY - 2020/10/2
Y1 - 2020/10/2
N2 - This study aimed to determine the effects of virtual keyboard designs and postures on task performance and muscle activity during tablet use. Eighteen healthy adults were randomly assigned to one of three postures (DESK, LAP, BED) to complete six sessions of 60-minute typing on a tablet with three virtual keyboards (STD, WIDE, SPLIT) twice in an experimental laboratory. Keystroke dynamics and muscle activity of the forearm and neck-shoulder regions were measured by electromyography. The split virtual keyboard was found to be associated with faster typing speed (SPLIT vs STD, p =.015; SPLIT vs WIDE, p <.001) and decreased muscle activity of extensor digitorum communis (SPLIT vs STD, p =.021). Lap posture was associated with faster typing speed (p =.018) and higher forearm muscle activity (p <.05). Typing performance decreased (p <.001) with elevated neck extensor muscle activity (p =.042) when the task duration prolonged. The split virtual keyboard showed potential to improve tablet ergonomics under various postures. Practitioner Summary: Tablets have become widely used for a variety of tasks and have gradually expanded into the realm of mobile productivity and education. Adequate designs of virtual keyboards for tablets show the potential for increased task performance and decreased muscle activity pertinent to typing activity and posture constraints imposed by non-traditional work positions. Abbreviations: WPM: words per minute; IKI: inter-key press interval; EMG: electromyography; EDC: extensor digitorum communis; FDS: flexor digitorum superficialis; CES: cervical erector spinae; UT: upper trapezius; EA: electrical activity; MVC: maximum voluntary contraction; APDF: amplitude probability distribution function.
AB - This study aimed to determine the effects of virtual keyboard designs and postures on task performance and muscle activity during tablet use. Eighteen healthy adults were randomly assigned to one of three postures (DESK, LAP, BED) to complete six sessions of 60-minute typing on a tablet with three virtual keyboards (STD, WIDE, SPLIT) twice in an experimental laboratory. Keystroke dynamics and muscle activity of the forearm and neck-shoulder regions were measured by electromyography. The split virtual keyboard was found to be associated with faster typing speed (SPLIT vs STD, p =.015; SPLIT vs WIDE, p <.001) and decreased muscle activity of extensor digitorum communis (SPLIT vs STD, p =.021). Lap posture was associated with faster typing speed (p =.018) and higher forearm muscle activity (p <.05). Typing performance decreased (p <.001) with elevated neck extensor muscle activity (p =.042) when the task duration prolonged. The split virtual keyboard showed potential to improve tablet ergonomics under various postures. Practitioner Summary: Tablets have become widely used for a variety of tasks and have gradually expanded into the realm of mobile productivity and education. Adequate designs of virtual keyboards for tablets show the potential for increased task performance and decreased muscle activity pertinent to typing activity and posture constraints imposed by non-traditional work positions. Abbreviations: WPM: words per minute; IKI: inter-key press interval; EMG: electromyography; EDC: extensor digitorum communis; FDS: flexor digitorum superficialis; CES: cervical erector spinae; UT: upper trapezius; EA: electrical activity; MVC: maximum voluntary contraction; APDF: amplitude probability distribution function.
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U2 - 10.1080/00140139.2020.1778097
DO - 10.1080/00140139.2020.1778097
M3 - Article
C2 - 32496886
AN - SCOPUS:85086947300
SN - 0014-0139
VL - 63
SP - 1312
EP - 1328
JO - Ergonomics
JF - Ergonomics
IS - 10
ER -