Reduced estrogen levels following menopause are known to contribute significantly to musculoskeletal deterioration, including osteoporosis, sarcopenia, and reduced muscle strength. Osteoporosis, in particular, is frequently accompanied by changes in spinal curvature among postmenopausal women. Proper sagittal spinal alignment is critical for maintaining biomechanical efficiency, load distribution, and postural stability. Disruption of this alignment impairs spinal function and increases the risk of vertebral fractures in individuals with low bone mass.1 While some studies suggest that decreased bone mineral density (BMD) may lead to sagittal imbalance, others propose that changes in spinal alignment—especially thoracolumbar kyphosis—may themselves be contributors to vertebral fractures, by increasing mechanical stress and reducing structural integrity.2, 3, 4

Several intrinsic and extrinsic factors, such as aging, spinal fusion, body weight, sex, and pelvic morphology, are known to influence sagittal spinal alignment. Most existing studies on spinopelvic parameters and sagittal imbalance have focused on elderly or general populations, while data specific to postmenopausal women remain limited.5 Moreover, the relationship between osteoporosis and spinal malalignment appears to be bidirectional, forming a potential vicious cycle: bone fragility may predispose individuals to postural deformities, while postural deformities may, in turn, accelerate bone loss.6 This complex interplay highlights the importance of exploring spinopelvic biomechanics in populations at risk. A more nuanced understanding of the interaction between lumbar spine and pelvic alignment may improve early detection and management of osteoporosis-related postural changes. Therefore, the aim of this study was to investigate the association between BMD, anthropometric characteristics, and sagittal spinopelvic alignment parameters in postmenopausal women diagnosed with osteopenia or osteoporosis.