Screen-based activities and physical complaints among adolescents from the Nordic countries

The cross-sectional association between screen-based activity and physical complaints (backache and headache) among students was examined in a sample of 31022 adolescents from Denmark, Sweden, Norway, Finland, Iceland and Greenland, as part of the Health behaviour in school-aged children 2005/06 (HBSC) study. Daily hours spent on screen-based activities and levels of physical complaints were assessed using self-reports.Logistic regression analysis indicated that computer use, computer gaming and TV viewing contributed uniquely to prediction of weekly backache and headache. The magnitude of associations was consistent across types of screen based activities, and across gender.The observed associations indicate that time spent on screen-based activity is a contributing factor to physical complaints among young people, and that effects accumulate across different types of screen-based activities.A rising prevalence of physical complaints such as back pain, neck and shoulder pain, and headache has been reported for adolescent populations [1]. Comparing repeated cross sectional surveys from 1991 to 2001, the odds of back pain weekly increased between 23% to 50% for boys and between 44% to 50% among girls across the 10-year period [1]. Parallel to the increase in physical complaints, adolescents spend an increasing amount of time on screen-based activities, such as TV, computer games, or other types of computer based entertainment [2]. These parallel trends might be causally related. A suggested mechanism is that consecutive periods of screen-based activities lead to sustained muscle tension and a lack of recovery from such tension, and subsequently back pain or headache [3]. In line with this hypothesis, excessive screen-based activities have been associated with an increased risk of physical complaints in young people [4-6]. A dosage-response relationship has been documented in some studies [6], while other studies have reported a nonlinear effect [4], or a weak associa