1 Terms, Concepts and Definitions Associated with Whiplash

1.1 Introduction

Whiplash-associated disorder (WAD) is a term that describes injury to the neck and its clinical manifestations, as a result of forceful, rapid back-and-forth movement of the neck. It is typically caused by motor vehicular accidents. In recent years, the reported cases of whiplash have considerably increased in many countries. It has been observed that this increase is due to multiple factors such as changes to car design, increased traffic density, psychosocial factors, and increased litigation.¹

Chronic pain and related functional disability result from injury. However, associated medicolegal, cultural,² and psycho-social perspectives play significant roles³ in resulting long-term consequences.

Understanding whiplash and its symptom manifestations require knowledge on several preclinical, clinical, and biosocial perspectives. This e-book on whiplash is prepared and organized from the perspective of a medical learner. In the format of clinical case stories we describe the clinical condition of whiplash. We characterize the relevant biomechanical concepts of injury; applied clinical anatomy of the head and neck structures involved in the injury; clinical picture, diagnosis and acute management of neck injury; before persistent neck pain, its effects on the patient; interventional management and non-interventional management of skeletal and soft tissue injury; and also discuss how to manage a complex patient of whiplash injury. The book is arranged in 10 chapters, each with a particular focus. Within each chapter, illustrations and tables are provided to help understanding and  make the content clinically applicable.

1.2. Definitions of Injury & Whiplash-associated Disorder

The term whiplash was introduced by an American physician, H.E. Crowe, at a symposium on traffic accidents in 1928.⁴ Since then, it has been widely used, mostly referring to neck injury due to motor vehicle accidents. Whiplash is an indirect cervical trauma. In the literal meaning of whiplash, a relatively minor force at the handle of a whip leads to a much larger and rapid movement at the end of the whip. Quite similarly, in whiplash, the term serves to largely describe both the mechanisms and symptoms associated with an indirect cervical spine injury. In 1995, the Quebec Task Force (QTF), sponsored by the Société d’assurance automobile du Quebec, was set up and delegated the task of defining and formulating clinical guidelines.⁵ Similar task forces and reviews came up from Australia,⁶ and later from Sweden⁷ through The Swedish Commission on Whiplash-related Injuries.

The QTF definition is as follows. ‘‘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  driving or other mishaps. The impact may result in bony or soft-tissue injuries (whiplash injury), which in turn can lead to a variety of clinical manifestations (Whiplash-Associated Disorders, WAD)’’. WAD is used to describe the clinical manifestations of whiplash injury.⁵

1.3. The Incidence & Prevalence of Whiplash-associated Disorder

Because there are significant differences in the actual occurrence and reporting of whiplash complaints following car accidents, it is difficult to establish a true incidence rate of the clinical problem. There is clear evidence that the reporting of whiplash varies widely among countries.² The reports from Quebec suggest a rate of 70 per 100,000 inhabitants,⁵ whereas it was 188 to 325 per 100,000 inhabitants in the Netherlands in 1994.⁸ In the United States, figures reported in 1970 suggest that up to 42% of accidents involve rear end impacts, and at least 20% of them could lead to symptoms in the neck.⁹ In 2000, whiplash was the most common emergency room-treated motor vehicular injury.⁸ Although there must be a temporal association with the development of whiplash symptoms and the accident, there is no evidence for a definitive time limit. However, local guidelines and insurance policies may necessitate symptoms to be reported within a particular period. Although rear end collisions might have similar prevalence across countries with similar vehicular densities, the actual development of whiplash or WAD varies significantly from country to country. This has been attributed to psychosocial and cultural influences.¹⁰ In Sweden, the incidence of whiplash is supposed to range from 1 to 3.2%/1000/year. This is said to represent 30% of all insurance claims after vehicular accidents. Versteegen et al, over a 20-year period, identified a 10-fold increase in the number of patients who complained of neck pain after having been involved in a traffic accident and gone to an emergency room; 3.4 visits per 100,000 inhabitants (1970–1974) to 40.2 visits per 100,000 (1990–1994).¹¹ Not much information is available regarding the exact prevalence of neck injuries leading to whiplash in Canada. Also, the prevalence could vary, depending on the time measured since one’s injury. A population-based incident cohort of 4,759 individuals showed that the median time of recovery from accidents causing neck trauma can significantly vary among individuals, and is possibly a result of several patient-related and social factors.¹² In Australia, due to changes in legislation, the claims for whiplash decreased by 68% in 1985 to 1986, when compared to 1982 to 1983, even with a possible increase in vehicular density.¹³ All these confounders along with estimates obtained from insurance claims give rise to unreliable estimates of its actual burden. However, it has been observed that, after an acute whiplash injury, up to 90% or more patients usually recover, with only minor on-going symptoms. Overall, there has been a steady increase in the number of patients with a diagnosis of whiplash. This poses a huge medical and economic burden on the society.⁴

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1.4 The Description of Quebec Task Force Classification of Grades of Whiplash-associated Disorder

Considering the importance of WAD, several task forces were commissioned from different countries. QTF published a consensus statement after considering the level of evidence at its time.⁵ WAD was graded into five categories on the clinical-anatomic axis and five categories on the time axis. Time axis was considered because it was primarily intended for acute evaluation and prognostication. The commonly quoted clinical-anatomic axis is graded based on severity and is shown in Table 1-1. Among the five grades, grade 0 does not lead to any symptoms and grade IV necessitates urgent trauma care.

TABLE 1-1 Quebec Task Force Classification System

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1.5. References

1. Galasko CS, Murray PM, Pitcher M, et al. Neck sprains after road traffic accidents: a modern epidemic. Injury 1993;24:155-7.
2. Ferrari R, Russell AS. Epidemiology of whiplash: an international dilemma. Ann Rheum Dis 1999;58:1-5.
3. Schiltenwolf M, Beckmann NA. Whiplash disorder–is it a valid disease definition? Pain 2013;154:2235.
4. Rydevik B, Szpalski M, Aebi M, Gunzburg R. Whiplash injuries and associated disorders: new insights into an old problem. Eur Spine J 2008;17(Suppl 3):359-416.
5. Spitzer WO, Skovron ML, Salmi LR, et al. Scientific monograph of the Quebec Task Force on Whiplash-Associated Disorders: redefining “whiplash” and its management. Spine 1995;20(8 Suppl):1s-73s.
6. Barnsley L, Lord S, Bogduk N. Whiplash injury. Pain 1994;58:283-307.
7. Whiplash injuries: diagnosis and early management: The Swedish Society of Medicine and the Whiplash Commission Medical Task Force. Eur Spine J 2008;17(Suppl 3):355-8.
8. Wismans KS, Huijkens CG. Incidentie en prevalentie van het ‘whiplash’- trauma. TNO report 94. R.B.V.041. TNO Road-Vehicle Research Institute, Delft, 1994.
9. States JD, Korn MW, Masengill JB. The enigma of whiplash injury. N Y State J Med 1970;70:2971-8.
10. Ferrari R, Obelieniene D, Russell A, Darlington P, Gervais R, Green P. Laypersons’ expectation of the sequelae of whiplash injury. A cross-cultural comparative study between Canada and Lithuania. Med Sci Monit 2002;8):Cr728-34.
11. Versteegen GJ, Kingma J, Meijler WJ, ten Duis HJ. Neck sprain in patients injured in car accidents: a retrospective study covering the period 1970-1994. Eur Spine J. 1998;7(3):195-200. Epub 1998/07/31. 12.
12. Suissa S. Risk factors of poor prognosis after whiplash injury. Pain Res Manag 2003;8:69-75.
13. Awerbuch MS. Whiplash in Australia: illness or injury? Med J Aust 1992;157:502.