Postural Hypervigilance and Perception of Correct Sitting Posture in Individuals With and Without Low Back Pain.

Objectives To verify if there is a difference in postural hypervigilance in sitting in individuals with and without low back pain. Additionally, to observe whether there is a difference in the perception of correct sitting posture between individuals with low back pain and without low back pain. Methods The present study has a cross-sectional observational design, as a sample size of 92 individuals, later divided equally into two groups (with low back pain and without low back pain). Two instruments were used: the hypervigilance scale to analyze the frequency that volunteers correct their sitting posture during the day, and posture scans to investigate the perception of volunteers about the correct sitting posture. The data were submitted to the Shapiro-Wilk Normality test. To compare the values of Hypervigilance Scale, the Mann-Whitney, Chi-Square, and Fisher Exact tests were used to assess correct sitting posture. Results There was no significant difference between postural hypervigilance in sitting between individuals with low back pain and without low back pain. There was no significant difference between the choice of correct sitting posture between the group of individuals with and without low back pain. Conclusion There is no difference between the choice of correct sitting posture and the amount of postural hypervigilance in individuals with or without low back pain.

Postural Hypervigilance and Perception of Correct Sitting Posture in Individuals With and Without Low Back Pain / Hipervigilância postural e percepção da postura correta sentada em indivíduos com e sem dor lombar

Abstract Objectives To verify if there is a difference in postural hypervigilance in sitting in individuals with and without low back pain. Additionally, to observe whether there is a difference in the perception of correct sitting posture between individuals with low back pain and without low back pain. Methods The present study has a cross-sectional observational design, as a sample size of 92 individuals, later divided equally into two groups (with low back pain and without low back pain). Two instruments were used: the hypervigilance scale to analyze the frequency that volunteers correct their sitting posture during the day, and posture scans to investigate the perception of volunteers about the correct sitting posture. The data were submitted to the Shapiro-Wilk Normality test. To compare the values of Hypervigilance Scale, the Mann-Whitney, Chi-Square, and Fisher Exact tests were used to assess correct sitting posture. Results There was no significant difference between postural hypervigilance in sitting between individuals with low back pain and without low back pain. There was no significant difference between the choice of correct sitting posture between the group of individuals with and without low back pain. Conclusion There is no difference between the choice of correct sitting posture and the amount of postural hypervigilance in individuals with or without low back pain.

Resumo Objetivos Verificar se há diferença na hipervigilância postural sentada em indivíduos com e sem dor lombar. Além disso, observar se há diferença na percepção da postura correta sentada entre indivíduos com dor lombar e sem dor lombar. Métodos O presente estudo possui delineamento observacional transversal, como tamanho amostral de 92 indivíduos, posteriormente divididos igualmente em dois grupos (com dor lombar e sem dor lombar). Foram utilizados dois instrumentos: a escala de hipervigilância para analisar a frequência que voluntários corrigem a postura sentada no dia; e o quadro de posturas para investigar a percepção dos voluntários sobre a postura correta sentada. Os dados foram submetidos ao teste de Normalidade de Shapiro-Wilk. Para comparar os valores da Escala de Hipervigilância foi utilizado o teste de Mann-Whitney e o teste Qui-quadrado e exato de Fisher para avaliação da postura correta sentada. Resultados Não houve diferença significativa entre a hipervigilância postural sentada entre indivíduos com dor lombar e sem dor lombar. Não houve diferença significativa entre a escolha da postura correta sentada entre o grupo de indivíduos com e sem dor lombar. Conclusão Não há diferença entre a escolha da postura correta sentada e quantidade de hipervigilância postural em indivíduos com ou sem dor lombar.

The trunk is exploited for energy transfers of maximal instep soccer kick: A power flow study.

The purpose of this study was to investigate the angular kinetic energy transfers and expenditure among the trunk (bisegmented), the pelvis and the kick limb during maximal soccer instep kicking, and to characterize kicking kinetics and kinematics. Eighteen adult male amateur soccer players (24.0 ± 4.1 years old) were assessed. Three-dimensional kinematics and ground reaction force were measured. A 6-degrees-of-freedom model was assumed, comprising the upper trunk, lower trunk, pelvis, thigh, shank and foot, and the thoraco-lumbar, lumbo-pelvic, hip, knee, and ankle joints. Angular kinematics and joint moments were computed. Power flow analysis was done by calculating the joint powers (to describe joint-to-segments energy transfers) and the proximal and distal segment powers (to describe segment-to-segment transfers). Power, kinematic and kinetic time series were presented to describe the energy flows' directions. The total mechanical energy expenditure (TMEE) at each joint was also calculated. The TMEEs pointed to substantial energy expenditure at the trunk (27% of the summed work produced by the analyzed joints). In the initial phases of kicking, the trunk generates downward energy flows from the upper to the lower trunk and from the lower trunk to the pelvis, and then to the lower limb, sequentially, which favors angular motions for ball contact. There is a formation and release of a tension arc only at the hip joint, and deceleration of the segments slightly sooner than ball contact, differently from theoretical accounts. There are energy flows, hitherto unknown, among the trunk, pelvis and kick limb, revealing mechanical strategies of kicking.

Pelvic Drop Changes due to Proximal Muscle Strengthening Depend on Foot-Ankle Varus Alignment.

BACKGROUND: Strengthening of hip and trunk muscles can modify pelvis and hip movements. However, the varus alignment of the foot-ankle complex (FAC) may influence the effects of muscle strengthening, due to the relationship of FAC alignment with pelvic and hip kinematics. This study evaluated the effects of hip and trunk muscle strengthening on pelvis and hip kinematics during walking, in subgroups with larger and smaller values of FAC varus alignment. In addition, this study evaluated the effects of hip and trunk muscle strengthening on hip passive and active properties, in the same subgroups. METHODS: Fifty-three women, who were divided into intervention and control groups, participated in this nonrandomized controlled trial. Each group was split into two subgroups with larger and smaller values of FAC varus alignment. Hip and trunk muscle strengthening was performed three times a week for two months, with a load of 70% to 80% of one repetition maximum. Before and after strengthening, we evaluated (1) pelvis and hip excursions in the frontal and transverse planes during walking, (2) isokinetic hip passive external rotator torque, and (3) isokinetic concentric and eccentric peak torques of the hip external rotator muscles. Mixed analyses of variance (ANOVAs) were carried out for each dependent variable related to walking kinematics and isokinetic measurements (α = 0.05). RESULTS: The subgroup with smaller varus alignment, of the intervention group, presented a reduction in pelvic drop after strengthening (P = 0.03). The subgroup with larger varus alignment increased pelvic drop after strengthening, with a marginal significance (P = 0.06). The other kinematic excursions did not change (pelvic anterior rotation P = 0.30, hip internal rotation P = 0.54, and hip adduction P = 0.43). The intervention group showed increases in passive torque (P = 0.002), peak concentric torque (P < 0.001), and peak eccentric torque (P < 0.001), independently of FAC alignment. These results suggest that FAC varus alignment influences the effects of strengthening and should be considered when hip and trunk muscle strengthening is used to reduce pelvic drop during walking.