Short Interventions to Prevent Trapezius Muscle Fatigue in Computer Work

"During each activity two interruptions/breaks were selected randomly from a set of ten predetermined actions:~Active break types:~* Move shoulder and upper back~* Swing arms near the body~* Three slow but forceful elevations of the shoulders, a relaxation exercise based on the principles developed by Jacobson~* Stand up and stretch~* Slowly turn head in all possible directions.~Passive break types:~* Tell a couple of jokes~* Stand up and have a drink~* Relaxing the trapezius~* Questions on actual posture and feelings of comfort / discomfort.~* A short rest on the couch"