The Most Common Coupled Motions in the Spine

What are the most common coupled motions in the spine?

A. Extension and lateral bending

B. Lateral bending and extension

C. Flexion and lateral bending

D. Lateral bending and rotation

Answer:

The most common coupled motions in the spine are lateral bending and rotation.

The most common coupled motions in the spine are lateral bending and rotation. These movements typically occur together due to the spine's anatomical structure and the way the joints and muscles function. Lateral bending refers to the side-to-side movement of the spine, where the vertebral column bends toward the right or left side. This bending occurs in the coronal plane and is intimately linked with the rotational movement, where the neck or body twists.

Contrary to what might be assumed, flexion and extension, which are movements in the sagittal plane allowing for bending forward and backward respectively, are typically not coupled in the spine. Essentially, when you bend to the side (lateral flexion), the structure of the spine naturally leads to a slight rotation in the same direction. This is due to the orientation of the facet joints between adjacent vertebrae, which guides these coupled movements.