Prolonged sitting is associated with increased risk for cardiovascular diseases and mortality. However, research into the physiological determinants underlying this relationship is still in its infancy. The aim of the study was to determine the extent to which occupational and leisure-time sitting are associated with nocturnal heart rate variability (HRV) in blue-collar workers. The study included 138 blue-collar workers (mean age 45.5 (SD 9.4) years). Sitting-time was measured objectively for four days using tri-axial accelerometers (Actigraph GT3X+) worn on the thigh and trunk. During the same period, a heart rate monitor (Actiheart) was used to sample R-R intervals from the electrocardiogram. Time and frequency domain indices of HRV were only derived during nighttime sleep, and used as markers of cardiac autonomic modulation. Regression analyses with multiple adjustments (age, gender, body mass index, smoking, job-seniority, physical work-load, influence at work, and moderate-to-vigorous physical activity) were used to investigate the association between sitting time and nocturnal HRV. We found that occupational sitting-time was negatively associated (p < 0.05) with time and frequency domain HRV indices. Sitting-time explained up to 6% of the variance in HRV, independent of the covariates. Leisure-time sitting was not significantly associated with any HRV indices (p > 0.05). In conclusion, objectively measured occupational sitting-time was associated with reduced nocturnal HRV in blue-collar workers. This indicates an attenuated cardiac autonomic regulation with increasing sitting-time at work regardless of moderate-to-vigorous physical activity. The implications of this association for cardiovascular disease risk warrant further investigation via long-term prospective studies and intervention studies.

Abstract

Objective: This cross-sectional study aimed at analyzing: 1. the main musculoskeletal symptoms (MSS) presented by hospital nursing workers and; 2. personal, occupational, and health factors related to MSS among them. Method: Two questionnaires were filled in by 245 nurse technicians (NTs) and licensed practical nurses (LPNs) (response rate 95%) associated with direct patient care sectors from a hospital. These questionnaires were: the standardized version of the Nordic Musculoskeletal Questionnaire (NMQ) and one including questions on 15 demographic independent variables potentially related to outcomes from the NMQ. Univariate analyses and binary logistic regression analyses were performed to identify which variables would explain the occurrence of MSS in different body regions. Results: The low back (57%), shoulder (52%), and neck (48%) were identified as the most affected regions. The logistic regression analysis showed that low back symptoms in the last 12 months were significantly associated with LPN activities (OR=2.36; CI=1.24-4.5) and previous sick leave due to MSS (OR=5.97; CI=1.2-29.1). Smoking was significantly associated with symptoms in the low back (OR=2.77; CI=1.13-6.8) and thoracic spine (OR=2.37; CI=1.04-5.40). Physical exercise showed a protective effect on the cervical spine (OR=0.42; CI=0.23-0.77). Previous sick leave was significantly associated with pain in the knees (OR=4.24; CI=1.33-13.5) and in the upper limbs (OR=5.36; CI=1.07-26.7). Conclusions: The nursing workers who were evaluated presented a high prevalence of MSS. Previous history of sick leave was strongly associated with the presence of symptoms in various body regions. These results indicate the need for preventive programs in the hospital environment in order to control more severe MSS in nursing professionals.

Prevalence of postural deviations and associated factors in children and adolescents: a cross-sectional study [I] Prevalência de variações posturais e fatores associados em crianças e adolescentes: um estudo transversal [A] Mariana Vieira Batistão, Roberta de Fátima Carreira Moreira, Helenice Jane Cote Gil Coury, Luis Ernesto Bueno Salasar, Tatiana de Oliveira Sato * Universidade Federal de São Carlos, (UFSCar), São Carlos, SP, Brazil [R] Abstract Introduction: Postural deviations are frequent in childhood and may cause pain and functional impairment. Previously, only a few studies have examined the association between body posture and intrinsic and extrinsic factors. Objective: To assess the prevalence of postural changes in school children, and to determine, using multiple logistic regression analysis, whether factors such as age, gender, BMI, handedness and physical activity might explain these deviations. Methods: The posture of 288 students was assessed by observation. Subjects were aged between 6 and 15 years, 59.4% (n = 171) of which were female. The mean age was 10.6 (± 2.4) years. Mean body weight was 38.6 (± 12.7) kg and mean height was 1.5 (± 0.1) m. A digital scale, a tapeline, a plumb line and standardized forms were used to collect data. The data were analyzed descriptively using the chi-square test and logistic regression analysis (signi icance level of 5%). Results: We found the following deviations to be prevalent among schoolchildren: forward head posture, 53.5%, shoulder elevation, 74.3%, asymmetry of the iliac crests, 51.7%, valgus knees, 43.1%, thoracic hyperkyphosis, 30.2%, lumbar hyperlordosis, 37.2% and winged shoulder blades, 66.3%. The associated factors were age, gender, BMI and physical activity. Discussion: There was a high prevalence of postural deviations and the intrinsic and extrinsic factors partially explain the postural deviations. Conclusion: These indings contribute to the understanding of how and why these deviations develop, and to the implementation of preventive and rehabilitation programs, given that some of the associated factors are modi iable. 10,6 (2,4) anos, massa corporal de 38,6 (12,7) kg e altura de 1,5 (0,1)

The aim of this study was to evaluate the short term effects of an exercise program on abdominal and back muscles resistance and hamstring flexibility among schoolchildren. Fifty eight healthy schoolchildren were divided into two groups: experimental (15 males and 14 females; mean age 12.2±1.8 years) and control (14 males and 15 females; mean age 11.9±2.1 years). The intervention was performed twice a week, on nonconsecutive days, during six weeks. The duration of each session was fifty minutes and they were composed by warming up aerobic exercises, isotonic and isometric abdominal and back muscle exercises and hamstring stretching. The intervention effects were evaluated through Kraus-Weber test (abdominal resistance), modified Biering-Sørensen test (back muscle resistance) and sit and reach test (hamstring flexibility). Data were analyzed by mixed-design two-way ANOVA, with one between-subjects and one within-subject (time) factors. The alpha level was set at P0.05. The experimental group improved back muscles resistance and hamstring flexibility, but not abdominal muscles resistance. There was a significant interaction between groups and time for back muscles resistance (P=0.018) and for hamstring flexibility (P=0.017). The 6-week training period showed positive results in improving back muscles resistance and hamstring flexibility of schoolchildren.