The position of the lumbar zygoapophyseal joints limits rotational movement potential primarily in which plane?

• A. Coronal
• B. Transverse
• C. Sagittal
• D. Frontal

Answer: (C)

The lumbar zygoapophyseal joints, also known as the facet joints, play a significant role in determining the range of motion within the lumbar spine. These joints are oriented in a way that restricts rotational movement potential, particularly in the transverse plane.

In the lumbar region, the facets are oriented primarily in a sagittal plane, which allows for flexion and extension movements while limiting excessive rotation. This orientation is crucial because the lumbar spine is designed to provide stability and support for the upper body while safeguarding the spinal cord and nerve roots.

While some movement in the transverse plane (rotation) does occur in the lumbar region, the design and alignment of the facet joints significantly restrict this type of motion compared to other regions of the spine, such as the cervical region, where rotation is more freely allowed due to their orientation. This restriction helps in preventing injury to the vertebrae and discs, which could occur with excessive rotational forces.

Therefore, the limitations on rotational movement potential are primarily a function of the sagittal orientation of the lumbar facet joints, confirming the significance of their anatomical positioning in overall spinal mechanics.