Neck injuries caused by whiplash are common consequences of car accidents, particularly rear-end collisions. Yet for years, “whiplash” has been a dirty word. The insurance industry has worked diligently to persuade the public that whiplash injuries are not real and that accident victims who complain about whiplash are fabricating symptoms to support fraudulent insurance claims.

Fortunately, doctors and engineers have advanced the understanding of whiplash injuries. The science of biomechanics has given personal injury lawyers the ammunition they need to dispel the myth that whiplash is not a legitimate cause of serious injury.

The science of whiplash

In a typical rear-end collision, the accident victim’s car is thrust forward much more rapidly than the speed at which a car normally accelerates. Initially, two things happen to the accident victim as the car rockets ahead. First, the victim’s back flattens against the seat as the seat moves forward. That forces the back to straighten abruptly and causes compression of the discs and joints in the back and neck. At the same time, the pelvis moves forward more quickly than the back, causing a rotation of the neck that contributes to injury.

Second, as the seat continues to push the victim’s body forward, the victim’s head moves backward until it makes contact with the headrest. The shearing forces produced by that movement do their damage well before the head’s movement is stopped by the headrest.

The next mechanism that produces a whiplash injury comes into play as the car begins to slow down. The car’s deceleration causes the victim’s body and head to move forward. Stepping on the brake or crashing into another vehicle will cause the car to decelerate more rapidly, increasing the forces that move the body and head forward.

As the accident victim moves forward, a seatbelt and shoulder harness typically restrains the torso. The head, however, has no similar restraint. The victim’s neck bends sharply as the head moves forward, straining ligaments, muscles, and nerves. Discs in the cervical spine may be forced out of position. Fibers in the cervical discs may be torn and nerve roots may be damaged.

All of that happens in less than a half second. The combination of forces that produce a rapid extension and flexion of the neck cause hidden damage that may not begin to produce symptoms until hour or days have passed following the collision.

Proof of whiplash

Insurance adjusters claim that whiplash injuries are faked because, unlike a broken bone, the injuries do not show up on an X-ray. Injuries to muscle joints, connective tissues, and nerves are not easy to diagnose. While an MRI might provide evidence of injury, MRIs are expensive and doctors are reluctant to order them. Doctors are inclined to base a whiplash diagnosis on a patient’s report of neck pain, giving insurance companies the opportunity to argue that the pain is not real.

Insurance companies are particularly likely to claim that a whiplash injury is fabricated when the injury victim reports no neck pain or stiffness in the immediate aftermath of the treatment. Fortunately, medical studies confirm that the delayed onset of pain and other symptoms is common. The authors of the leading treatise on whiplash injuries point out that symptoms usually do not appear for 12 to 48 hours, and that it is not uncommon for the onset of pain to be delayed until several days after the collision. Pain often reaches its highest level of severity 72 hours after the injury occurs, but every patient is different. Some may experience peak levels of pain that begin later and then last for weeks or months.

Low-speed whiplash injuries

For years, the insurance industry funded studies of low-speed car crashes and relied on the results of those studies to argue that neck injuries only result from rear-end collisions when the car that causes the crash is traveling faster than 15 mph. They also pointed to the lack of damage (or only minor damage) to the accident victim’s car as evidence that the victim did not sustain a serious injury.

More objective research has established that whiplash injuries can occur when impacts occur at much slower speeds. Even when the crash does not cause significant damage to a car, whiplash can produce substantial injury to the accident victim’s neck.

One study found that a change of velocity of 5 mph produced whiplash injuries lasting longer than one month in 20% of accident victims. The impact speed that is required to increase a car’s velocity by 5 mph depends upon the mass of the vehicle that collides with the car, but studies have found that a 6 to 8 mph impact can be sufficient to produce whiplash injuries in some cases.

Most cars are built to withstand a rear-end impact of 8 to 12 miles per hour. That means that whiplash injuries can occur even when the victim’s car sustains no visible damage.

Science confirms that car accident victims who experience neck pain in the days following even a minor rear-end collision have legitimate injuries. Regardless of the misinformation spread by insurance companies, whiplash injuries are real, and car crash victims who suffer from them deserve compensation.