Asakawa Deanna S, Crocker George H, Schmaltz Adam, Jindrich Devin L
Department of Kinesiology, California State University San Marcos, 333. S. Twin Oaks Valley Rd., San Marcos, CA, USA.
Department of Kinesiology, California State University San Marcos, 333. S. Twin Oaks Valley Rd., San Marcos, CA, USA.
J Electromyogr Kinesiol. 2017 Jun;34:6-13. doi: 10.1016/j.jelekin.2017.02.007. Epub 2017 Feb 24.
Users actuate touchscreen computers by applying forces with their fingers to the touchscreen, although the amount and direction of the force is unknown. Our aim was to characterize the magnitude, direction and impulse of the force applied during single finger (tapping and sliding in four directions) and two finger gestures (stretch and pinch). Thirteen subjects performed repeated trials of each gesture. Mean(±SD) resultant force was 0.50(0.09)N for tap, 0.79(0.32)N to 1.18(0.47)N for sliding gestures, 1.47(0.63)N for pinch and 2.05(1.13)N for stretch. Mean resultant force was significantly less (p<0.04) for tap than for all gestures except slide right. The direction of force application was more vertical for the two-finger gestures as compared to the single- finger gestures. Tap was the fastest gesture to complete at 133(83)ms, followed by slide right at 421(181)ms. On average, participants took the longest to complete the stretch gesture at 920(398)ms. Overall, there are differences in forces, force direction, and completion times among touchscreen gestures that could be used to estimate musculoskeletal exposure and help forge guidelines to reduce risk of musculoskeletal injury.
用户通过用手指向触摸屏施加力来操作触摸屏电脑，尽管力的大小和方向是未知的。我们的目的是描述在单指（四个方向的点击和滑动）和双指手势（伸展和捏合）过程中施加的力的大小、方向和冲量。13名受试者对每个手势进行了重复试验。点击的平均（±标准差）合力为0.50（0.09）N，滑动手势的合力为0.79（0.32）N至1.18（0.47）N，捏合的合力为1.47（0.63）N，伸展的合力为2.05（1.13）N。点击的平均合力明显小于（p<0.04）除向右滑动外的所有手势。与单指手势相比，双指手势的力的施加方向更垂直。点击是完成速度最快的手势，用时133（83）毫秒，其次是向右滑动，用时421（181）毫秒。平均而言，参与者完成伸展手势用时最长，为920（398）毫秒。总体而言，触摸屏手势在力、力的方向和完成时间上存在差异，这些差异可用于估计肌肉骨骼暴露情况，并有助于制定指导方针以降低肌肉骨骼损伤风险。
