Coffee intake and development of pain during computer work

Forty eight subjects all working fulltime, 22 with chronic shoulder and neck pain and 26 healthy pain-free subjects, were recruited to perform a computer-based office-work task for 90 min. Nineteen (40%) of the subjects had consumed coffee (1/2 -1 cup) on average 1 h 18 min before start. Pain intensity in the shoulders and neck and forearms and wrists was rated on a visual analogue scale every 15 min throughout the work task.During the work task the coffee consumers exhibited significantly lower pain increase than those who abstained from coffee.Subjects who had consumed coffee before starting a pain provoking office work task exhibited attenuated pain development compared with the subjects who had abstained from coffee intake. These results might have potentially interesting implications of a pain-modulating effect of caffeine in an everyday setting. However, studies with a double blind placebo controlled randomized design are needed.Shoulder and neck pain occur commonly during work involving very low levels of muscle activity, such as office work with computers, with prevalence rates around 10 % [1-3]. Recently, we have reported that computer office-work performed continuously for 90 min, with time pressure and high precision demands, induced substantial pain in the shoulders and neck as well as in the forearm operating the computer mouse both in subjects with chronic pain and in healthy references [4,5]. Of the participants in this study, nearly half of them had ingested coffee before attaining the laboratory experiment. Reduced muscle pain after caffeine administration have been reported during dynamic exercise of >60% of maximal capacity [6,7] and during static grip to exhaustion tasks [8]. The present study sought to determine if subjects who had consumed coffee before starting the computer office-work exhibited different time course in the pain development than subjects who had abstained from coffee intake.Forty-eight subjects, 22 with chronic shoulder and ne