SUMMARY
The aim of this study was to evaluate the behaviour of postural variables and the associated factors, like back pain and life habits, in schoolchildren during a period of four years. Forty-two school children underwent a postural assessment using Digital Image-Based Postural Assessment software. They also answered the self-administered questionnaire titled, “Back Pain and Body Posture Evaluation Instrument” to evaluate their back pain and life habits. We observed a significant trend of forward head, thoracic hyper kyphosis, and lumbar hyper lordosis in the entire group, as well as a trend of cervical rectification in girls. Both boys and girls presented a constant frequency in back pain, but girls presented higher prevalence along the years. We found a high prevalence of poor sitting posture in male (between 72.2-89.5%) and female (between 73.3-100%). We also found that girls had poor posture due to the way they carried their school supplies. However, occurred a decrease of time spent in front of television for male (from 87% to 10.5%) and female (from 93.3% to 0%). Significant changes occurred in analysed variables over evaluation period.