HYPERFLEXION

Occurs when a segment of the spine is subjected to force, either direct or indirect, pushing it towards the front of the vertebral body, resulting in excessive bending beyond the normal range of motion.

Common association: Often linked to head-on collisions.

Mechanism: Upon impact, the driver's head continues forward, and if the speed and force are sufficient, the head's weight forces the chin towards the chest, causing hyperflexion injury.

Consequences: can lead to an anterior vertebral compression (wedge) fracture and potential intervertebral disc herniation.

- Ligament involvement: Posterior ligaments may stretch and tear, potentially allowing the vertebrae to shift out of alignment (subluxation).

- Spinal canal disruption: Subluxation of the vertebral column disrupts the continuity of the spinal canal, causing stretching and compression of the spinal cord, which can impact spinal cord blood flow.

- Disc involvement: Disc material can also protrude into the spinal canal, moving toward the spinal cord.

HYPEREXTENSION

Causes extreme extension of the spinal column, often resulting from incidents like falls, chin impact with an immovable object, or rear-end collisions.

Whiplash connection: Whiplash represents a milder form of this injury mechanism.

Excessive force is absorbed by the more flexible regions of the spine, leading to stretching or tearing of the anterior longitudinal ligaments, potential fractures, subluxation of the vertebrae, and disc ruptures.

Cord compression: Injuries can also occur when the hyperextended spinal cord is excessively stretched, causing compression by the ligamentum flavum and resulting in cord contusion and ischemia.

People with degenerative disc disease and / or cervical stenosis, face a higher risk of developing spinal cord injuries due to hyperextension, mainly because of the presence of osteophytes and spinal canal narrowing.

AXIAL LOADING

Axial loading, or vertical compression: substantial vertical force is applied to the spinal column, leading the vertebral bodies and intervertebral disks to absorb the energy, causing what's known as a compression or burst fracture.

- Fracture consequences: The result is the release of bone fragments and disk material in various directions, including into the spinal canal.

- Spinal cord impact: The collapsing bone fragments can tear and compress the spinal cord that they encircle.

- Buckling of cervical spine: In some cases, there may be a "buckling" of the cervical spine involving a combination of flexion and extension at different vertebral levels.

- Common causes: Injuries from this mechanism often occur during activities like shallow diving or head-first tackling and typically lead to significant spinal cord injury

ROTATIONAL INJURIES

Rotational injuries: Result from spine twisting

Lateral flexion of cervical spine: Associated with axial rotation

Consequences of rotational forces:

  - Stretch and rupture of posterior ligaments

  - Facet dislocation

  - Compression fracture of bone structure

-Occurrence of injury:

  - Side impact motor vehicle crash (especially unrestrained occupants)

  - Force applied to the side of the head or jaw (e.g., "hook" in boxing