Oxygenation, EMG and position sense during computer mouse work. Impact of active versus passive pauses

Abstract

We investigated the effects of active versus passive pauses implemented during computer mouse work on muscle oxygenation and EMG of the forearm extensor carpi radialis muscle, and on wrist position sense. Fifteen healthy female subjects (age: 19-24 years) performed a 60-min mouse-operated computer task, divided into three 20 min periods, on two occasions separated by 3-6 days. On one occasion a passive pause (subjects resting) was implemented at the end of each 20-min period, and on another occasion an active pause (subjects performed a number of high intensity extensions of the forearm) was implemented. Also at the end of each 20-min period, test contractions were conducted and subjective ratings of fatigue and stress were obtained. Another parameter of interest was total haemoglobin calculated as the summation of oxy-and deoxy-haemoglobin, since it reflects blood volume changes. The most interesting findings were an overall increasing trend in total haemoglobin throughout the mouse work (P<0.001), and that this trend was greater for the active pause as compared to the passive pause (P<0.01). These data were accompanied by an overall increase in oxygen saturation (P<0.001), with a tendency, albeit not significant, toward a higher increase for the active pause (P=0.13). EMG amplitude and median frequency tended to decrease (P=0.08 and 0.05, respectively) during the mouse work but was not different between pause types. Borg ratings of forearm fatigue showed an overall increase during the activity (P<0.001), but the perceptions of stress did not change. Position sense did not change due to the mouse work for either pause type. While increasing trends were found for both pause types, the present study lends support to the hypothesis of an enhancement in oxygenation and blood volume for computer mouse work implemented with active pauses. However, a presumption of an association between this enhancement and attenuated fatigue during the mouse work was not supported.

Effect of Different Types of Rest-Break Interventions on Neck and Shoulder Muscle Activity, Perceived Discomfort and Productivity in Symptomatic VDU Operators: A Randomized Controlled Trial

“…In addition, Lacaze, Sacco Ide, Rocha, et al reported that active breaks with stretching and joint mobilization reduced muscle discomfort significantly better than passive breaks [41]. The positive effect of dynamic contractions on a lower level of discomfort after rest-break intervention could result from increased muscle oxygenation [28].…”

“…Individual operators can perform some physical activity, exercise or change their posture during the breaks [26]. Some authors use the word "pause" instead of rest break or break [27,28]. Pauses during computer work tasks can be passive or active.…”

“…Pauses during computer work tasks can be passive or active. Passive pauses in these appraisals mean that operators leave their computer tasks, and sit and relax during this period, while during active pauses operators are required to perform specific movements, e.g., shoulder elevation [27,28].…”

“…A few studies compared the beneficial effects of passive and active pauses, with focus on oxygenation in muscles [20,28]. However, there is still limited clinical trial research that addresses the effects of different types of activities during rest-break interventions among VDU operators in terms of changes in local muscle loads, discomfort and productivity.…”

The position of a standard optical computer mouse affects cardiorespiratory responses during the operation of a computer under time constraints

“…The increasing use of computers is believed to have caused computer-related disorders (CRDs), such as eye fatigue, stiff shoulders, upper extremity pain, lower back pain, and mental stress [3,4]. Factors that can contribute to these conditions include the setting of the computer screen, which affects working posture [5], operating the computer for extended periods [6][7][8], and tasks that require repetitive and monotonous motions [9][10][11][12]. Additionally, mental stress levels are known to increase with the duration of computer-related tasks.…”