Prevalence of low back pain in young Brazilians and associated factors: Sex, physical activity, sedentary behavior, sleep and body mass index.

Background: Low back pain (LBP) has become increasingly common, but the prevalence of this complaint and associated factors in young people remains controversial.

Objective: This study aimed to identify the prevalence of LBP and to explore the existence of associated factors (sex, physical activity, sedentary lifestyle, sleep, body mass index and waist circumference).

Methods: This study considered all complaints of the lumbar region (acute or chronic) as LBP, which can irradiate to the backside and legs, lasting a minimum of 24 hours.

Body surface posture evaluation: construction, validation and protocol of the SPGAP system (Posture evaluation rotating platform system).

Background: Several posture evaluation devices have been used to detect deviations of the vertebral column. However it has been observed that the instruments present measurement errors related to the equipment, environment or measurement protocol. This study aimed to build, validate, analyze the reliability and describe a measurement protocol for the use of the Posture Evaluation Rotating Platform System (SPGAP, Brazilian abbreviation).