Blackstone Janet M, Karr Catherine, Camp Janice, Johnson Peter W
Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, USA.
Ergonomics. 2008 Jun;51(6):872-89. doi: 10.1080/00140130701797959.
By the age of five years, 75% of the children in the USA are using computers and at this age they are only one-half to two-thirds the size of and about one-fifth as strong as their adult counterparts. Fourteen children between five and eight years of age and their same-gender biological parents (giving a total of 28 subjects) were evaluated using both a standard and a smaller, child-proportional input device during standardised mouse and keyboard tasks. Typing and computer mouse performance were measured with tracking software, wrist posture was measured with an electrogoniometer and electromyography was used to measure finger flexor and extensor muscle activity in the right arm. With the small mouse, both children and adults performed the mouse task significantly faster and made significantly fewer errors. When using the standard-sized mouse and keyboard, children worked with significantly greater ulnar deviation and significantly less extension than their adult counterparts. When children used the smaller mouse, finger flexor muscle activity, finger extensor muscle activity and ulnar deviation significantly decreased, with little change in wrist extension compared to the standard mouse. No significant differences were observed between the standard and small keyboards for children or their parents. Compared to their adult counterparts, children had to apply twice the relative force, as a percentage of their maximum capacity, to activate the buttons and keys on the input devices. These measured differences may have application in the design of computer input devices for children.
到五岁时，美国75%的儿童都在使用电脑，而这个年龄段的儿童体型只有成年对应人群的二分之一到三分之二，力量也只有成年对应人群的五分之一左右。对14名5至8岁的儿童及其同性别的亲生父母（共28名受试者）在标准化鼠标和键盘任务中使用标准输入设备和较小的、按儿童比例缩放的输入设备进行了评估。使用跟踪软件测量打字和电脑鼠标操作表现，使用电子测角仪测量手腕姿势，并使用肌电图测量右臂手指屈肌和伸肌的活动。使用小鼠标时，儿童和成人完成鼠标任务的速度都明显更快，出错也明显更少。使用标准尺寸的鼠标和键盘时，儿童比成年对应人群工作时尺骨偏斜明显更大，伸展明显更少。当儿童使用较小的鼠标时，与标准鼠标相比，手指屈肌活动、手指伸肌活动和尺骨偏斜明显减少，手腕伸展变化不大。在儿童或其父母使用标准键盘和小键盘之间未观察到显著差异。与成年对应人群相比，儿童必须施加两倍于其最大能力百分比的相对力来激活输入设备上的按钮和按键。这些测量出的差异可能在儿童电脑输入设备的设计中有应用价值。
