Musculoskeletal Strain: The most common cause of back pain after a motor vehicle collision (MVC) is musculoskeletal strain due to the sudden force exerted on the spine and surrounding muscles during the accident. This is often due to the rapid acceleration-deceleration forces involved in MVCs.

Herniated Disk: The force of an MVC can cause disks in the spine to herniate, leading to back pain due to nerve compression or irritation.
Fractures: Vertebral fractures, including compression fractures, can occur due to the trauma of an MVC, leading to back pain.
Ligament Sprains: Similar to musculoskeletal strains, ligaments in the spine can be sprained during an MVC, causing pain and stiffness.

Spinal Cord Injury: Although less common, spinal cord injuries can occur after an MVC and are critical to identify early due to the potential for significant and permanent neurological damage.
Abdominal Aortic Dissection: Back pain after an MVC could also be a sign of an abdominal aortic dissection, a life-threatening condition that requires immediate medical attention.
Kidney Injury: Trauma to the kidneys can cause back pain and must be considered, especially if there are signs of hematuria or other indicators of renal injury.

Osteoporotic Compression Fractures: While more common in older populations with osteoporosis, these fractures can occur after minor trauma, including an MVC, and should be considered in at-risk individuals.
Spinal Epidural Hematoma: A rare but potentially devastating condition where bleeding occurs into the epidural space surrounding the spinal cord, which can compress the cord and lead to neurological deficits.
Cauda Equina Syndrome: A rare condition where the nerves in the spinal canal are compressed, leading to severe neurological symptoms, including loss of bladder and bowel control, and requires urgent medical intervention.