Which structure helps maintain spinal alignment and prevent injury during movement?

The choice that encompasses all options is correct because each of the listed structures plays a vital role in maintaining spinal alignment and providing stability during movement.

Intervertebral discs serve as shock absorbers between the vertebrae, allowing for flexibility while also preventing excessive movement that can lead to injury. They help to distribute load and maintain alignment through their hydration and structural integrity.

Facet joints, which are located at the back of the vertebrae, facilitate controlled movement of the spine while providing stability. They prevent excessive rotation and forward or backward bending, thereby supporting the alignment of the spinal column during various physical activities.

The posterior longitudinal ligament helps stabilize the spine by running along the back of the vertebral bodies and the intervertebral discs. It aids in preventing hyperflexion and provides additional support to the spinal structures.

All of these components work synergistically to ensure that the spine maintains its proper alignment when subjected to dynamic movements and loads, effectively reducing the risk of injury. Therefore, acknowledging the combined contribution of intervertebral discs, facet joints, and the posterior longitudinal ligament highlights the comprehensive nature of spinal stability.