Which cervical level marks the beginning of coupled motion in the spine?

Which cervical level marks the beginning of coupled motion in the spine?

• A. C1-C2
• B. C3-C4
• C. C2-C3
• D. C4-C5

Answer: (C)

Coupled motion occurs when movement in one plane is accompanied by movement in another due to the way the facet joints align. In the cervical spine, the upper levels move with a lot of pure rotation (the C1-C2 joint is mainly rotation with little lateral bending). Once you reach below that, starting at the C2-C3 level, rotation is accompanied by lateral bending to the same side. This is where the typical cervical coupled pattern begins and it continues through the lower subaxial levels. So the first level where coupled motion appears is between C2 and C3.

Coupled motion occurs when movement in one plane is accompanied by movement in another due to the way the facet joints align. In the cervical spine, the upper levels move with a lot of pure rotation (the C1-C2 joint is mainly rotation with little lateral bending). Once you reach below that, starting at the C2-C3 level, rotation is accompanied by lateral bending to the same side. This is where the typical cervical coupled pattern begins and it continues through the lower subaxial levels. So the first level where coupled motion appears is between C2 and C3.