High prevalence of inadequate sitting and sleeping postures: a three-year prospective study of adolescents.

There is a paucity of information regarding the development of body posture during adolescence. This three-year prospective study aimed to evaluate sitting and sleeping postures among adolescents, and to determine whether these postures are associated with age and sex. We assessed 525 adolescents aged 11-16 years from the fifth to eighth grades. These adolescents were reassessed three years later. The Back Pain and Body Posture Evaluation Instrument was used to evaluate the sleeping posture and three sitting positions: sitting to write, to use a computer, and during leisure activities. Our findings indicated a low prevalence of adequate sleeping and sitting postures at baseline, with a decrease in prevalence observed after three years for all postures. These changes were similar for both sexes. Moreover, we found a strong reduction of adequate posture prevalence for younger adolescents, but the oldest adolescents demonstrated no significant differences after three years. Early, rather than late, adolescence is a critical period for establishing inadequate sitting and sleeping postures. This has implications for posture throughout adulthood; hence, interventions targeted at this age group are needed.