Lumbar Spine Alignment in Six Common Postures: An ROM Analysis With Implications for Deformity Correction.

Area of Science:

• Spinal biomechanics and surgical fusion strategies.
• Radiographic analysis of lumbar spine alignment and motion.

Background:

• The optimal position for lumbar spine fusion remains undetermined.
• Achieving maximum residual function post-fusion is essential for patient outcomes.

Purpose of the Study:

• To compare lumbar spine alignment across six common postures.
• To quantify the loss in range of motion (ROM) relative to standing.

Main Methods:

• A cross-sectional study involving 70 low back pain patients.
• X-rays were taken in slump sitting, forward bending, supine, half squatting, standing, and backward bending.
• Lumbar spine range of motion (ROM) was measured using sagittal Cobb angles (L1-S1).

Main Results:

• Slump sitting and forward bending induced the greatest lumbar flexion.
• Backward bending resulted in greater lumbar extension compared to standing.
• Fusion in standing position may lead to a mean loss of 47.6° flexion and 5.9° extension.

Conclusions:

• The lumbar spine exhibits significant flexibility across various postures.
• Differences in motion exist between postures and spinal segments.
• Fusion based on the standing lordotic posture may substantially reduce lumbar ROM, particularly flexion.