Definition• Sudden hyperextension and hyperflexion injury to neck• An acceleration/ deceleration mechanism of Energy transfer to the neck• Whip-like movement
Whiplash-Associated Disorders (WAD)• Given the wide variety of symptoms that are associated with whiplash injuries the Quebec Task Force on Whiplash- Associated Disorders, coined the phrase, Whiplash-Associated Disorders.[
Whiplash Associated Disorders (WAD)• Classed by severity of signs and symptoms- Québec Task Force (QTF)• WAD 0 No complaints or physical signs• WAD 1 Neck complaints but no physical signs• WAD 2 Neck complaints and musculoskeletal signs• WAD 3 Neck complaints and neurological signs• WAD 4 Neck complaints and fracture / dislocation• Most whiplash injury results from low impact collisions
Pathophysiology• Interaction sequence for a collision lasting approximately 300 milliseconds.
0 ms• Rear car structure is impacted and begins to move forward and/or crushes• Occupant remains stationary• No occupant forces
100 ms• Vehicle seat accelerates and pushes into occupant’s torso (i.e. central portion of the body in contact with seat)• The torso loads the seat and is accelerated forward (seat will deflect rearward)• Head remains stationary due to inertia
150 ms• Torso is accelerated by the vehicle seat and may start to ramp up the seat• Lower neck is pulled forward by the accelerated torso/seat• The head rotates and extends rapidly rearward hyper-extending the neck
175 ms• Head is still moving backwards• Vehicle seat begins to spring forward• The torso continues to be accelerated forward• The head rotation rearward is increased and is fully extended
300 ms• Head and torso are accelerated forward• Neck is “whipped” forward rotating and hyper-flexing the neck forward• The head accelerates due to neck motion and moves ahead of the seat back
Causes• “Railroad spine” first coined in 1919 following train collisions.• Following invention of cars, number of whiplash-related injuries risen sharply due to an increase in rear-end motor vehicle collisions.
Incidence• US National Highway Traffic Safety Administration (1995)• 53% of 5.5 million RTA victims suffered whiplash injury www.londonpainclinic.com
Prevalence of whiplash-associated disorder symptomsSymptom Males Females (%) (%)Neck/shoulder pain 100 100Headache 78.4 86.1Numbness/tingling or pain in 37.8 46.4arms/handsNumbness/tingling or pain in 23.5 28.3legs/feetDizziness/unsteadiness 41.4 48.3Nausea 21.6 33.9Ringing in the ears 21.4 20.5Concentration problems 24.1 27.8Low back pain 61.9 64.6 Ferrari R, et al. Ann Rheum Dis 2005; 64:1337-1342. Widespread pain seen after whiplash in car-crash victims, but not in survivors without whiplash [Rheumawire > News; Sep 30, 2005]
Chronic WhiplashComplex interaction between many factors: Biological Psychosocial Legal Economics Beliefs / Attitudes Psychological factors are also hypothesized to influence the existence of whiplash-related cognitive impairments.
Education• Explain benign nature of WAD• Avoid confusing and conflicting info• Watch for factors leading to pain chronicity• Home / work programmes as effective as physiotherapy• Teach relaxation and stress management• Educate posture and neck care
Education• Ergonomics at home and work• Home program of heat and cold & exercises• Self Monitor stress, sleep and mood• Headaches• Avoid excessive investigation
Prevention• Head restraints• 3 in 4 not properly adjusted! www.londonpainclinic.com
Prognosis• 25% better within one week• Most better within 1 month• Only 2% not recover at 1 yr• With other injuries:• 19% better within 1 wk• 30% within 1 month• 4% not recover at 1 yr N=2810 (all waiting for compensation) The Effect of Socio-Demographic and Crash-Related Factors on the Prognosis of Whiplash. J Clin Epidemiol Vol. 51, No. 5, pp. 377–384, 1998
Prognosis• Lower rate of recovery:• Multiple injuries• Female• Older age, every decade increase in age, likelihood of recovery decreases by 14%• Larger number of dependents,• Married status,• Not being employed full time, low income• Low education•
Prognosis• Being in a truck time.or bus (less in cars)• Being a passenger, 15% lower for passengers than drivers• Collision with a moving object,• Colliding head-on or sideways (rear collision better)•
Prognosis• Wearing a seatbelt! (Head restraints better outcome)• Neck rotated or side bent• Previous neck pain (females) and cervical deg. changes• Lawyer involvement! (proof they are a pain in the neck)
Rule of thumb• Those with continuing symptoms three months after the accident are likely to remain symptomatic for at least two years, possibly much longer