Table 1.
Risk of bias checklist
| Scoring | ||
|---|---|---|
| Internal validity (measurements) | ||
| 1 | Was muscle activity before the control and experimental condition comparable (i.e. an equal baseline)? | A full point (1) was assigned if muscle activity was equal at baseline |
| 2 | Were the control and experimental conditions randomized? | A full point (1) was assigned if the control and experimental conditions were randomly assigned to the participants or balanced across participants |
| Internal validity (intervention) | ||
| 3a | Did the experimental manipulation result in the intended increased stress level? |
A full point (1) was assigned if the effect of the stress intervention was tested in the study and showed an increase Half a point (1/2) was assigned if a reference to a study that did was provided Half a point (1/2) was assigned if more than one intervention was performed and only in one of the two the effect of the stress intervention was tested in the study and showed an increase |
| 3b | Do the stressful manipulations offer escape possibilities? |
A full point (1) was assigned if it was not possible to ignore the stressful manipulation, and compensate by e.g. a decreased work pace Half a point (1/2) was assigned if more than one intervention was performed and only in one of the two it was not possible to ignore the stressful manipulation, and compensate by e.g. a decreased work pace |
| 4 | Did the experimental manipulation introduce an unintended extra motor component, influencing EMG outcomes? | A full point (1) was assigned if the experimental manipulation did not introduce an unintended extra motor component that influences the EMG outcomes |
| External validity | ||
| 5a | Is the study population representative for computer workers? |
A full point (1) was assigned if the study population was completely relevant for computer workers Half a point (1/2) was assigned if the study population was representative for subgroup of computer workers (e.g. only students or only men/women) |
| 5b |
Are the studied tasks representative for computer work? |
A full point (1) was assigned if the studied task reflected realistic computer work |
| 5c | Is the stress intervention representative for stressors in a realistic occupational setting? | A full point (1) was assigned if the intervention reflected realistic stressors |