Question #13

A healthy human can rotate their back by approximately 40°. Where is most of this movement occurring?

Sacral spine

Thoracic spine

Thoracic and lumbar spine equally

Thoracic, lumbar and sacral spine equally

Lumbar spine

Rotation occurs mainly in the thoracic spine with the lumbar spine contributing < 5°. Since the sacrum is fused this does not contribute to movement of the spine.

Cervical

• Lateral flexion - 45°
• Flexion (chin can touch chest)
• Extension
• Rotation - 80° (occurs at first two cervical vertebrae as the typical cervical vertebrae have articular lips in the coronal plane which prevent rotation from C3-C7).

Thoracic

• Flexion - 45°
• Lateral flexion - 15°
• Rotation - 35-40°
• Extension - 25°

Lumbar

• Flexion - 60°
• Lateral flexion - 15°
• Rotation < 5°
• Extension - 35°

Movement of the different parts of the spine are largely determined by the position of the articulating facets on the vertebral bodies:

1. Cervical vertebra have articular facets in the coronal plane, this prevents rotation from C3-C7.
2. Thoracic vertebra have articular facets in the vertical plane (on the arc of a circle) this allows rotation in the thoracic spine.
3. Lumbar vertebra have articular facets in the sagittal plane, again limiting rotation.

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