Can cervical fusion alter gait posture, balance, trunk rotation, and head-turning mechanics?

Cervical fusion can plausibly influence whole-body gait mechanics, particularly when multiple levels are fused, but these effects are not yet established as fusion-specific clinical outcomes. In an 83-year-old, pre-existing myelopathy, lumbar/hip disease, deconditioning, and postoperative rehabilitation may substantially shape gait and balance.

Clinical and functional evidence

• Arthrodesis consistently restricts motion at fused cervical levels; multilevel procedures generally produce greater overall restriction. Functional head-rotation tasks may therefore require altered cervical–thoracic or trunk movement strategies.
• Prospective cervical spondylotic myelopathy cohorts, often including decompression with fusion, show postoperative changes—frequently improvements—in walking speed, cadence, step characteristics, lower-limb motion, and compensatory pelvic/lumbar movement over approximately 3–12 months.
• Postural sway and balance may improve after surgery, but dynamic/reactive balance deficits can persist compared with healthy peers. These findings demonstrate that gait can change after surgery, but cannot determine whether change reflects fusion, neurologic recovery after decompression, rehabilitation, or their combination.

Biomechanical mechanisms

• Fusion reduces movement at treated levels, while three-dimensional and finite-element evidence supports increased adjacent-level flexion/extension motion and increased adjacent-segment strain after one- and two-level fusion. This redistribution provides a credible mechanism for altered posture, cervical–trunk coordination, trunk rotation, and head-turning during walking.
• A downstream lumbopelvic effect is biomechanically coherent: pelvic motion couples with cervical/lumbar displacement, and pelvic tilt changes sacral slope. Cervical myelopathy has been associated with increased anterior pelvic tilt and lumbar lordosis during gait.

Clinical implications

• No controlled postoperative cervical-fusion study has directly measured head-turning or trunk rotation during gait, or quantified in-vivo lumbar/pelvic loading. Consequently, altered lumbopelvic loading should not be presumed from fusion or attributed to it without individualized assessment.

Bottom line

• Cervical fusion can plausibly alter gait posture, balance, head–trunk mechanics, and indirectly lumbopelvic mechanics through motion restriction and compensation; direct, predictable changes in lumbar or pelvic loading remain unproven.