To investigate the association between behavioral risk factors, specifically postural habits, with the presence of structural changes in the spine of children and adolescents. 59 students were evaluated through the self-reporting Back Pain and Body Posture Evaluation Instrument e and the spine panoramic radiographic examination. The spine curvatures were classified, based on Cobb' angle, as normal or altered in the saggital plane and as normal or scoliotic in the frontal plane. Data were analyzed using SPSS 18.0, from descriptive statistics and chi-square association test (α=0,05). The prevalence of postural alterations was 79.7% (n=47), of which 47.5% (n=28) showed frontal plane alterations and 61% (n=36) sagital plane alterations. Significant association was found between the presence of thoracic kyphosis and female gender, practice of physical exercise only once or twice a week, sleep time greater than 10 hours, inappropriate postures to sit on the bench and sit down to write, and transport of school supplies. Lumbar lordosis was associated with improperly transportation of school backpack (asymmetric); and scoliosis was associated with the practice of competitive sport and sleep time greater than 10 hours. Lifestyle may be associated with postural alterations. It is important to develop health policies in order to reduce the prevalence of postural alterations with a reduction of associated risk factors.

Objective. to verify the validity and reproducibility of using the flexicurve to measure the angles of the thoracic and lumbar curvatures.Method. 47 subjects were evaluated by: (1) palpation and marking of the spinous processes using lead markers, (2) using X-rays in the sagittal plane to measure the Cobb angles, (3) molding the flexicurve to the spine, and (4) drawing the contour of the flexicurve onto graph paper. The angle of curvature was determined with the flexicurve based on a 3rd order polynomial.Results. No differences were found between the Cobb angles and the angles obtained using the flexicurve in thoracic and lumbar curvatures (). Correlations were strong and significant for the thoracic (, ) and lumbar (, ) curvatures. Excellent and significant correlations were found for both the intraevaluator and interevaluator measurements.Conclusion. The results show that there is no significant difference between the values obtained using the flexicurve and those obtained using the X-ray procedure and that there is a strong correlation between the two methods. This, together with the excellent level of inter- and intraevaluator reproducibility justifies its recommendation for use in clinical practice.

To estimate the prevalence of lateral and anteroposterior postural changes in female adolescents and to investigate whether these changes are associated with certain socioeconomic, demographic, anthropometric, or behavioral variables. This epidemiologic survey included a representative sample of 495 high school students from regular day school programs in the city of São Leopoldo, Rio Grande do Sul, Brazil, which is in the South region of Brazil. The students, who were 14 to 18 years old, were assessed in October and November of 2004. Postural changes were defined as skews in the spinal curvature, identified through noninvasive postural assessment. The prevalence of lateral changes was 66% (95% confidence interval (CI): 61.5% to 70.0%) vs. 70% for anteroposterior changes (95% CI: 65.2% to 73.5%). Lateral changes were more prevalent in students with a normal body mass index (prevalence ratio (PR) = 1.32; 95% CI: 1.09 to 1.59) and in those who watched television for more than 10 hours weekly (PR = 1.16; 95% CI: 1.02 to 1.32). The prevalence of anteroposterior changes was higher in students whose parents/guardians had no schooling or only had elementary schooling (female guardians: PR = 1.30, 95% CI of 1.09 to 1.55; male guardians: PR = 1.20, 95% CI of 1.02 to 1.40) and in students who were overweight or obese (PR = 1.33; 95% CI of 1.19 to 1.48). The high prevalence of postural changes observed is reason for concern since these changes can translate into spinal problems in the medium to long term. Health professionals, including physical education teachers, should be trained to perform postural assessments, which should be routinely done in schools.

The effective force applied on the crank, the index of pedalling effectiveness, and the economy of movement at 60, 75, 90, and 105 rev/min cadences were examined in nine cyclists and eight triathletes. Tests were performed on two days. Maximal oxygen uptake was measured and the second ventilatory threshold was estimated on day 1 using a stationary bicycle. On day 2, the four different cadences were tested at about 5% below the second ventilatory threshold. A strain gauge instrumented clip-less pedal mounted on the bicycle enabled us to measure the normal and tangential forces exerted on the pedal, while the pedal and crank angles were monitored with the aid of a video system. Based on this information, the effective force and the index of pedalling effectiveness were calculated. Cyclists produced significantly more effective force and a higher index of pedalling effectiveness at 60 and 75 rev/min and were significantly more economic at all cadences than triathletes. The significant and positive correlation between effective force and economy at all cadences suggests that improvement of the effective force would reflect on economy.