Forensically, acceleration/deceleration injuries are often referred to as whiplash injuries. They frequently occur as a result of high-speed vehicle accidents, abusive head trauma/physical abuse, or falls. These injuries result from rapid changes in velocity involving the forward and backward movement of the head and neck and can lead to potential damage to the soft tissues, ligaments, and muscles in the cervical region as well as severe head injuries.
Here’s a breakdown of the mechanism:
Sudden Change in Velocity: When the body experiences a sudden stop or start, different parts of the body may move at different speeds. For example, in a car crash, the torso might be restrained by a seatbelt and stop with the vehicle, but the head continues to move forward at the speed the vehicle was moving, leading to injury.
Shearing Forces: The differential movement between the fixed and mobile parts of the body creates shearing forces. These forces can cause significant damage to tissues, particularly in the brain, where the brain tissue moves at a different rate than the skull.
Resulting Injuries:
Diffuse Axonal Injury (DAI): A type of traumatic brain injury (TBI) and one of the most severe outcomes of shearing forces. The axons (nerve fibers) in the brain are stretched and torn as the brain moves rapidly within the skull. This can lead to widespread brain damage and is a common result of high-speed impacts from coup-contrecoup forces.
Whiplash: A specific type of acceleration/deceleration injury, often seen in rear-end car collisions, is whiplash or cervical hyperextension injuries. This involves a rapid back-and-forth movement of the neck, leading to soft tissue damage.
Internal Organ Damage: The rapid deceleration can also cause internal organs to collide with the body’s skeletal structure, leading to bruising, bleeding, or even rupture.
Signs and Symptoms of acceleration/deceleration injuries can vary depending on the organs affected, but some common signs include:
Signs and Symptoms of DAI:
Loss of consciousness
Headache
Dizziness
Nausea and/or vomiting
Difficulty with balance and/or coordination
Confusion
Cognitive impairments, such as memory loss or difficulty concentrating
Signs and symptoms of whiplash and internal organ injury:
Abdominal Pain: Persistent or severe pain in the abdomen can indicate damage to organs like the liver, spleen, intestines, or internal hemorrhage.
Nausea and Vomiting: These symptoms can be a sign of internal bleeding, traumatic brain injury (TBI), or organ damage.
Difficulty Breathing: This can occur if the lungs or diaphragm are injured.
Dizziness or Lightheadedness: These symptoms can result from internal bleeding leading to a drop in blood pressure or from whiplash injuries to the neck.
Weakness or Feeling Faint: Similar to dizziness, this can be due to significant blood loss.
Cervicogenic Headaches: Headaches that generate from the neck and radiate to the temple, top or front of the head, or down the neck
Numbness: In the arms and/or hands.
Neck pain: Pain that worsens when moving the neck, or stiffness and difficulty moving the neck
Headaches: Headaches that often start at the base of the skull
Pain: In the shoulders, upper back, arms, or jaw
Blurred vision
Tiredness, irritability
