Biomechanical modelling studies have revealed the impact of passive mechanical properties of spinal soft tissues on spinal configuration. This study extends prior work by evaluating the involvement of trunk abdominal and intramuscular pressure (IMP), on spinal geometric compensation, using a validated finite element spine model. The model included the vertebrae, rib cage, IVD, pelvis, ligaments, abdominal cavity and abdominal and spinal muscles. Over a fixed pelvis, the model underwent a 60° forward flexion. Muscles and the abdominal cavity were modelled as fluid-filled solid entities containing hydrostatic pressure elements, enabling IMP and intra-abdominal pressure (IAP) quantification. Changes in lumbar segmental rotations, spine range of motion (RoM) and curvature (thoracic kyphotic (TKA) and lumbar lordotic angle (LLA)) were analyzed following a 1) 10-fold increase and decrease in paraspinal IMP and a 2) 20-fold increase in IAP, relative to the validated model. A 10-fold increase in paraspinal IMP or 20-fold increase in IAP decreased lumbar ROM by a maximum of 8.4° and increased the TKA and LLA by a maximum of 5.8° and 4.7°, respectively during forward flexion. Heightened IAP correlated with decreased paraspinal IMP. Conversely increased paraspinal IMP correlated with IAP reductions. This investigation showed a synergistic interplay between paraspinal IMP and IAP on segmental mobility and spine geometry. The shared influence may suggest a clinical impact of targeting both muscle groups in scenarios involving lower back dysfunction.

Neglected severe rigid kyphoscoliosis can lead to rapid curve progression, presenting a challenge for surgical correction and carrying higher risks of mortality, morbidity, and neurological injury, potentially resulting in permanent paralysis. Halo-pelvic traction (HPT) has been reported to be effective in improving curve flexibility, assisting the surgical correction process, and reducing the likelihood of neurological complications. We report the case of a 15-year-old girl with mosaic Turner syndrome and severe kyphoscoliosis, who experienced progressive curve progression (from 41° to 158°) over a span of 6 years. Preoperative halo gravity traction (HGT) was unsuccessful. To address this deformity, HPT was performed with CT-based navigation for pelvic pin insertion, considering her relatively small pelvis and pelvic obliquity. This technique allowed for precise pin placement, reducing the risk of injury to major arteries, nerves, and abdominal/pelvic organs, while enabling the creation of a more versatile halo-pelvic frame designed to enhance patient comfort and mobility. The patient underwent weekly distraction using HPT for 4 weeks, during which her coronal Cobb angle reduced from 158° to 103° and her kyphotic angle decreased from 90° to 64°. With this notable improvement in the primary spinal curvature, we proceeded with posterior spinal fusion. Notably, this approach obviated the need for vertebral column resection. As a result, we achieved a correction rate of 53.8% in the coronal Cobb angle and 55.6% in the kyphotic angle without neurological injury.

Postural differences have been evident between female and male athletes, but there is insufficient information on how these differences are characterized in different sports branches. Our aim in this study was to compare the static postures of female and male athletes paired into identical sports. We included 172 athlete participants (86 female and 86 males) who were paired by same chronological age, sporting age, and sports branch. We performed posture analyses of these athletes, using the DIERS formetric 4D device. Specifically, we evaluated and recorded their trunk length, sacrum distance, sagittal imbalance, coronal imbalance, pelvic obliquity, pelvic torsion, pelvic inclinations, pelvic rotation, kyphotic angle, lordotic angle, vertebral rotation, and trunk torsion. We found comparable sagittal imbalance, coronal imbalance, pelvic rotation, vertebral rotation, and trunk torsion similar in females and males (p > .05), but females had a wider sacrum, their pelvic structures were more oblique and anteriorly tilted, and they had more pelvic inclination angles and bigger kyphosis and lordosis angles. Male athletes had longer trunk lengths and more pelvic torsion. The kyphosis and lordosis angles of the female athletes were bigger than those of male athletes, but they were still within normal limits. The lumbar lordosis angles of male athletes were below normal limits. In conclusion, female athletes exhibited a more balanced spinal posture than male athletes.