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Designing for Upper Torso and Arm Anatomy
Published in Karen L. LaBat, Karen S. Ryan, Human Body, 2019
Lordosis is most frequently seen in the lumbar spine. It is sometimes called “swayback” and may be a compensation for thoracic kyphosis. Structural lordosis may be the result of osteoporotic lumbar vertebral fractures or other medical conditions. Pregnancy and obesity can shift the center of gravity resulting in lordosis. Muscle activity in the neck and lumbar spine produces changes in spinal lordosis and increased back extension increases lumbar lordosis. Wearing heavy gear like backpacks or body armor, or carrying heavy loads, may produce temporary lumbar lordosis and/or pain. Soldiers (n = 863) who wore body armor for four or more hours per day during their combat zone deployments reported an increased incidence of back, neck, and upper limb musculoskeletal pain (Konitzer, Fargo, Brininger, & Reed, 2008).
The Body as a Mechanical System
Published in R. S. Bridger, Introduction to Human Factors and Ergonomics, 2017
Quadrupedal animals and human babies have a single spinal curve running dorsally from pelvis to head. The thorax and abdomen hang from the spine and exert tension, which is resisted by the spinal ligaments, the apophyseal (facet) joints, and the back muscles. In adult humans, the spine is shaped such that it is close to or below the COG of the superincumbent body parts, which are supported “axially”—that is, the effect of weight-bearing in the standing posture is to compress the spine (Adams and Hutton, 1980). This compression is resisted by the vertebral bodies and the intervertebral disks. The “cervical” and “lumbar” spines are convex anteriorly—a spinal posture known as “lordosis.” It is the presence of these lordotic curves that positions the spine close to or directly below the line of gravity of the superincumbent body parts. The effect is to reduce the energy requirements for the maintenance of the erect posture and place the lumbar motion segments in an advantageous posture for resisting compression (Klausen and Rasmussen, 1968; Adams and Hutton, 1980, 1983). The thoracic spine is concave anteriorly and is strengthened and supported by the ribs and associated muscles.
Anatomy, Biomechanics, Work Physiology, and Anthropometry
Published in Stephan Konz, Steven Johnson, Work Design, 2018
The spine is concave backward in the cervical and lumbar region; it is concave forward in the thoracic region. Lordosis is an increase in lumbar curvature—a swayback posture, with the stomach protruding. Kyphosis is an increase in thoracic curvature—a hunchback posture, with the shoulders rolling forward and the person slouching. Scoliosis is a bending of the spine to the side (i.e., from a front view).
Effects of cycling on the morphology and spinal posture in professional and recreational cyclists: a systematic review
Published in Sports Biomechanics, 2023
José A. Antequera-Vique, José M. Oliva-Lozano, José M. Muyor
The pelvis is the base of the spine, and its degree of inclination affects the sagittal curves of the spine (Garbin Savarese et al., 2020). Several authors observed that subjects with a greater pelvic tilt while standing have greater lumbar lordosis in this posture, and in contrast, those subjects with a retroverted pelvis show less lumbar lordosis (Barrey et al., 2007; Schwab et al., 2006). These authors justified their findings, given the crucial role played by the pelvis in postural balance by modifying its inclination to readjust the centre of gravity. Other authors stated that a more pronounced pelvis tilt correlated with greater flexibility in the hamstrings (Holliday & Swart, 2021a). The results of the studies reviewed seem to agree that the degree of extensibility influences the position of the pelvis in maximum trunk flexion postures with extended knees but not in the standing or cycling posture.
Validation of the Fitbit Zip and Fitbit Flex with pregnant women in free-living conditions
Published in Journal of Medical Engineering & Technology, 2018
A. St-Laurent, M. M. Mony, M. È. Mathieu, S. M. Ruchat
The adaptations in gait during pregnancy, caused by morphological changes, could also be responsible for a less accurate estimation of the different PA parameters. Aguiar et al. [27] found that pregnant women had a greater anterior and posterior pelvis tilt over the gait cycle, typically related to a greater lumbar lordosis. Change in tilt could lead to a miscalculation from the monitors (especially underestimation), particularly those placed on the hip. Interestingly, Dinallo et al. [28] found that, in the same treadmill conditions, the ActiGraph recorded significantly less counts/min and time spent in MVPA at 32 weeks of gestation compared to 20 weeks, suggesting that pregnancy-induced morphological and biomechanical adaptations could change the accuracy of PA monitors. This is an important element to consider in future activity monitor validation studies during pregnancy. Although the women were taught how to correctly place the monitors on the hip, we did not verify monitor placement during the seven-day wearing period. It is therefore possible that incorrect positioning of one or the other monitor occurred and leads to inaccurate recordings. Finally, we should be careful when comparing a wrist-worn and a hip-worn monitor. Some studies found significant differences between attachment sites using the accelerometer GT3X [29,30]. Our differences between the ActiGraph GT3X and the Fitbit Flex could only be linked to the placement of the monitors as the Fitbit Zip was also placed on the hip.
Factors in development of low back pain during anteflexion in children identified by a multiple logistic regression model
Published in SICE Journal of Control, Measurement, and System Integration, 2023
Yushin Yoshizato, Kiyohisa Natsume
In this study, low tension in the anterior thigh muscles, accompanying pelvic tilt, and a decrease in lumbar lordosis caused LBPAF. Additional research is needed to measure the tone of the anterior and posterior muscles and to record the posture of paediatric patients with LBPAF. In addition, because the small sample size of paediatric LBPAF was a limitation of this study, it is necessary to increase the number of children. In the present study, the MLR model was built using all participants with LBPAF to determine the best model for describing paediatric LBPAF. Therefore, there is the potential for overfitting. In the future, the sample size of paediatric LBPAF should be increased, and predictive models without overfitting should be developed using CV and ensemble learning.