EPIDEMIOLOGY OF WHIPLASH ASSOCIATED DISORDERS
The term whiplash injury has been used since the late 1920s, when H.E. Crowe coined the term at a medical meeting in San Francisco. It was originally described as an injury mechanism to the neck, but was later also used to define the actual symptoms after such an event. The first known case report was published in the Journal of the American Medical Association in 1953, when Gay and Abbot described 50 patients who had been exposed to whiplash mechanism in car collisions. It was reported that the majority had been exposed to rear-end collisions and that the majority were also examined between one and 24 months after the collision, thus representing a mix of patients with acute or persistent symptoms. Cervical pain with radiation into the occipital region of the skull, shoulder girdle or upper extremities were reported as common symptoms, but irritability, poor concentration and subjective vertigo were also described.
People who are exposed to energy transfer to the neck, in sports, falls or other mishaps, may also experience cervical pain. After such events, however, it is less common that the injury is labeled “whiplash”, but instead other terms, such as neck strain, neck sprain or simply neck injury, are used. The term whiplash associated disorder (WAD) was introduced in 1995 by the Quebec Task Force (QTF), who published the first systematic review on whiplash injuries. The term was intended to reflect that whiplash is an injury mechanism, and the consequences of the mechanism were the spectrum of symptoms (disorders). The QTF formulated the following conceptual definition:
Whiplash is an acceleration-deceleration mechanism of energy transfer to the neck. It may result from rear-end or side-impact motor vehicle collisions, but can also occur during diving or other mishaps. The impact may result in bony or soft-tissue injuries (whiplash injury) which in turn may lead to a variety of clinical manifestations (whiplash-associated disorders).
The reason for excluding frontal collisions from the definition is not discussed in the report and is likely to be an error, since it is known that 25-30% of whiplash injury occurs in such impact direction. The QTF also suggested a classification of WAD into five categories based on clinical signs and symptoms. This classification is mostly used to classify WAD in the acute phase. Since the publication of the QTF findings, the term WAD has been increasingly used in the medical literature, and it is also a frequently used term in insurance medicine.