Figure 1.
The picture illustrates the standard keyboard layout in the middle position with the tablet in the portrait orientation. Markers on the forearm, hand, and thumb segments as well as the tablet computer provided 3D location and orientation of these segments during the experiment. Users were allowed to support their forearms or elbows on the table and to use available padding. The participant pictured here has given written informed consent, as outlined in the PLOS consent form, to publication of their photograph.
Figure 2.
The 11 different configurations involved different combinations of the following 3 independent variables: (a) 2 device orientations, (b) 2 keyboard layouts, and (c) 3 keyboard locations.
Figure 3.
Significant interaction effects between Keyboard Layout and Device Orientation.
Least squares (and standard error) values are presented for (a) mean self-reported discomfort across device orientation and keyboard layout, (b) median wrist adduction across device orientation and keyboard layout, (c) median IP flexion across device orientation and keyboard layout, and (d) wrist joint range of motion for the flex./ext. axis across device orientation and keyboard layout. The superscript letters in the figure represent results from the Tukey post-hoc analysis: same letters denote groups without significant differences. Values with different letters are ranked such that A>B>C.
Table 1.
Least squares mean (and standard error) net typing speed, self-reported discomfort and self-reported task difficulty for main effects Device Orientation, Keyboard Layout, and Keyboard Location, and p-values for interactions.a
Table 2.
Least squares median (and standard error) joint angles (o) for main effects Device Orientation, Keyboard Layout, and Keyboard Location, and p-values for interactions.a,b
Table 3.
Least squares joint range of motion (and standard error) for main effects Device Orientation, Keyboard Layout, and Keyboard Location, and p-values for interactions.a,b
Figure 4.
Significant interaction effects between Keyboard Location and Keyboard Layout.
Least squares (and standard error) values are presented for (a) mean median wrist extension across keyboard location and keyboard layout, (b) median CMC extension across keyboard location and keyboard layout, (c) median CMC pronation across keyboard location and keyboard layout, and (d) CMC joint range of motion for the sup./pron. axis across keyboard location and keyboard layout. The superscript letters in the figure represent results from the Tukey post-hoc analysis: same letters denote groups without significant differences. Values with different letters are ranked such that A>B>C.