Because WI is caused by trauma, WI patients are usually involved in some type of accident a few hours before presentation. Symptoms do not generally take more than 24 hours to develop.

The most common symptoms in WI patients are neck pain, stiffness and headaches, often originating from the base of the skull. Pain may also radiate to shoulders, arms and upper back and usually worsens with movement. Dizziness and vertigo are not uncommon and paresthesias, particularly in the arms, as well as cognitive disorders, may also be present [19][20]. Those cognitive disorders may encompass blurred vision and tinnitus. Psychological symptoms such as irritability, problems with concentration and memory and sleep disturbances may also occur and even result in depression.

Initially, the exact tissue damage causing these symptoms is usually not obvious [21]. Vertebrae, vertebral joints with ligaments and intervertebral discs and neck muscles may be involved as well as vessels and nervous tissue, particularly dorsal root ganglia.

To date, the origin of pain in chronic whiplash is not fully understood. While tissue damage may persist in some cases [22], many people suffering from chronic whiplash presumably adopt poor postures in order to avoid pain. Such pain may initially have been caused by tissue damage but is later probably sustained by the poor posture itself [23].

A medical history involving a car accident or other traumatic experiences, as well as indications to physical abuse generally lead to the suspected diagnosis of WI.

A thorough clinical examination focusing on the patient's head and neck may reveal further evidence of a traumatic neck lesion. The skin may exhibit bruises, cuts and abrasions, while head and neck movement may be painful. In order to anatomically localize possible damage, cautious, controlled head movements up, down and to both sides have to be evaluated. Nerve damage may lead to numbness, tingling or other pathological sensations in different parts of the body and the patient should be asked if they experience such sensations.

Radiographic imaging is generally applied to check for fractures. If additional serious injuries are suspected, the corresponding imaging techniques (computerized tomography and magnetic resonance imaging) may help to detect them.

As long as no definitive conclusion regarding the severity of WI and possible involvement of the cervical spine or nervous tissue is made, the patient should wear a neck-stabilizing collar and a backboard.

WI therapy aims at pain control and restoration of head and neck mobility. Here, the latter is strongly associated with the former since painful movements may prompt the patient to adapt to poor postures and to avoid certain movements. This, in turn, may cause additional pain and eventually lead to chronic whiplash.

While rest may be necessary to avoid additional damage in severe cases of WI, the aim should be to restore full mobility as soon as possible. Therefore, pharmacological therapy should be complemented with the appropriate exercises.

In detail, therapy usually consists of:

• Analgesics. Generally, paracetamol and non-steroidal anti-inflammatory drugs are applied to control pain.
• Muscle relaxants. May be necessary to further control pain and allow for greater mobility and restful sleep.
• Local anesthetics. If analgesics and muscle relaxants do not suffice to alleviate muscle pain, an injection of local anesthetics may be considered.
• Stabilizing collars. Collars may be initially helpful to stabilize the neck and avoid additional tissue damage. They should, however, not be used for longer periods of time since they impair recovery due to muscle loss.
• Physiotherapy. The physiotherapist has the patient perform certain movements to strengthen muscles and regain mobility. The physiotherapist may also assist in correcting poor postures.
• Home exercises. In addition to supervised exercises in physiotherapy, the patient should carry out some simple movements and stretching exercises at home. These may include neck rotation, head tilting and shoulder rolling, as long as the overall condition of the patient allows these movements.

Prognosis of WI strongly depends on the severity of the initial injury. While patients suffering from minor WI usually recover within a few weeks, moderate injuries involving  ligament strains and muscle stiffness may require a few months to heal. Severe WI involves damage to the cervical spine, the vertebral joints or to nervous tissue. Their prognosis is doubtful. In some cases, chronic whiplash may develop and permanent neck pain or even disability may ensue.

If a car accident leads to WI, the severity of the reported accident does not necessarily affect the patient's prognosis in a significant way. Allegedly minor accidents happening at low speed may even expose the car's occupants to greater acceleration and deceleration forces since the crumple zone does not deform and thus, the metal does not absorb physical forces [17][18].

WI results from traumatic experiences, most commonly from car accidents. Indeed, this type of neck injury is one of the most frequent injuries sustained in motor vehicle accidents and it is therefore often seen in emergency departments [2]. Car accidents involving considerable rear-end, front or side impacts provoke a sudden acceleration and subsequent deceleration that neck muscles and bones fail to withstand. The head moves rapidly forward and backward, muscles, ligaments and tendons are overstretched, and the bones forming the cervical spine may be damaged as well as intervertebral discs, vessels and nerves.

Other situations exposing the neck to similar physical forces, e.g. sports accidents and physical abuse, may cause similar tissue damage and trigger WI.

The very same event may cause WI of different severity to different individuals, depending on the affected person's posture at impact, their overall condition and gender. One of the most important factors that determine the severity of the injury is the patient's awareness of the upcoming impact. Those factors influence neck stability at the time of the impact.

A healthy nervous system is a prerequisite for an effective stabilization response. Furthermore, women generally suffer more severe WI than men, a fact that may be due to less muscling and more fragile bones. Awareness is especially important to withstand minor to moderate physical forces whereas the patient's strength may not suffice to resist a strong impact even when they are aware of it. Previous studies have shown that the driver of a car involved in an accident often suffers less severe WI than the passenger, because the driver may have important split seconds to prepare themselves for the impact after seeing the other vehicle in the rear mirror.

Due to the high number of car accidents, WI is very common. The number of WI has considerably increased during the last decades, presumably due to the increase in traffic volume. Of note, the growing incidence of WI is one of several factors contributing to rising insurance premiums. In order to prevent insurance frauds, a standardized system for WI diagnosis should be developed. At the same time, the automotive industry is working on new interior designs to reduce the number of WI victims.

Incidence rates of up to almost 1 per 100 persons have been reported, whereby this high incidence corresponds to women aged 20 to 24 in the United States [3]. The mean incidence, independent of age and gender, seems to range between 1 and 3 per 1,000 people. Such rates have been reported from Canada [1], Australia [4] and the Netherlands [5]. Whereas somewhat higher rates have been reported for Western Europe [6], low incidences have been calculated for Northern Europe [7].

Chronic whiplash is diagnosed when symptoms persist for more than six months. Although some studies report that the vast majority of cases achieves full recovery and only 6% of all patients suffer from residual neck pain for long periods of time, other studies estimate this number to be as high as 66%.

Due to the high number of anatomical structures possibly damaged during WI, the pathophysiology behind that traumatic injury is complex. No two WI happen under exactly the same circumstances, which is why experiments with dead bodies or animals are of little value.

The physical forces observed during a car accident or similar traumatic experiences may damage the cervical spine, its vertebral joints and capsular ligaments [8][9] and the craniovertebral junction [10], in addition to cervical muscles [11], vertebral arteries and dorsal root ganglia [12][13]. While muscle injuries are certainly responsible for a significant share of neck pain and stiffness [14], only damage to vertebral joints could be linked to chronic whiplash [15].

Because full recovery is the overall aim of any WI treatment, scientific studies nowadays focus on joint involvement in WI. In this context, it has been found that neuromuscular patterns are altered in patients suffering from chronic whiplash. However, as of yet it is not known whether alterations in muscle activity result from pathological neuronal input or if they are  part of an intended, protective strategy to avoid pain. Such protective measures are not unlikely, since different types of adaptive responses have been observed in WI patients [16].

Whiplash injury can be prevented by avoiding situations causing it.

With regards to car accidents, that means seatbelts should always be used, cars with airbags should be preferred and the seat headrest should be properly adapted to the respective passenger in each journey. The seat headrest is of particular importance in avoiding WI because the headrest stops the head when snapping backwards after an impact. These safety instructions basically apply to all kinds of vehicles, i.e. for cars, buses but also roller coasters.

Since contact sports such as football and rugby may also lead to WI, these sports should be carried out with the proper safety equipment.

Physical abuse should not only be avoided due to ethical and legal reasons, but also be reported to the authorities when suspected.

Chronic whiplash may be prevented by compliance with the treatment regimen. Patients should be consulted towards a certain behavior that may help to prevent the pain from becoming chronic [24].

Whiplash injury (WI) affects both hard and soft tissues of the neck that are exposed to considerable acceleration and deceleration forces, e.g. during rear-end car accidents. Due to the sudden exertion of strong external forces, the affected person is not able to maintain his or her head upright. The head is rapidly thrown forward, backward or even sideways. Tendons and ligaments are stretched beyond their limits and this provokes tissue damage that results in a variety of symptoms called whiplash-associated disorders [1]. 

Although rear-end car accidents are the most common cause for WI, other traumatic experiences may also lead to WI. Collisions from the front or from the side may also cause WI. Of note, for an accident to provoke WI, it does not necessarily need to happen at high speed. Furthermore, WI has been associated with sports accidents, particularly those happening in contact sports such as football or rugby, physical abuse, punching and shaking (such as shaken baby syndrome), domestic and other types of accidents.

Anamnesis usually leads to the suspected diagnosis of WI. Tissue damage may then be confirmed with diagnostic imaging. Radiographic imaging and computerised tomography are the techniques of choice in order to detect fractures and other damages to the skeleton, whereas magnetic resonance imaging may be applied to reveal soft tissue damage.

Pharmacological therapy is generally based on analgesics, e.g. on paracetamol and non-steroidal anti-inflammatory drugs. Appropiate exercises may help patients to regain mobility. However, chronic whiplash may develop if symptoms last for more than six months.

WI results from car accidents, sport accidents, abuse and other traumatic experiences that involve a sudden forceful back-and-forth movement of the head. This movement causes damage to tissue structures of the neck, e.g. to the cervical spine, its vertebrae, muscles, ligaments, vessels and nerves. The medical terms for injuries like this are cervical sprain and cervical strain and they are associated with neck and shoulder pain and stiffness, headaches, dizziness and possibly with cognitive disorders.

If WI is diagnosed due to preliminary report and clinical examination, imaging techniques such as X-rays are likely performed, to check if any anatomical structure suffered serious damage.

Therapy consists of pharmacological treatment with analgesics and muscle relaxants with additional physiotherapy and home exercises.

While mild and moderate cases of WI usually achieve full recovery after a few weeks or months, severe cases involving considerable damage to the cervical spine or nerves may take a long time to heal. In these cases, the prognosis for full recovery is worse.

Some patients do still experience neck pain years after the accident and are thus suffering from chronic whiplash. While there is a certain correlation between severity of the initial lesion and probability of chronic whiplash, it is not possible to give a certain prognosis.

1. 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):8S–58S
2. Quinlan KP, Annest JL, Myers B, Ryan G, Hill H. Neck strains and sprains among motor vehicle occupants – United States, 2000. Accid Anal Prev. 2004; 36:21–27.
3. Quinlan KP, Annest JL, Myers B, Ryan G, Hill H. Neck strains and sprains among motor vehicle occupants-United States, 2000. Accid Anal Prev. 2004;36(1):21-27.
4. Miles KA, Maimaris C, Finlay D, Barnes MR. The incidence and prognostic significance of radiological abnormalities in soft tissue injuries to the cervical spine. Skeletal Radiol. 1988; 17:493–496.
5. Wismans KSHM, Huijkens CG. Incidentie en prevalentie van het ‘whiplash’-trauma. TNO report. Delft: TNO Road-Vehicle Research Institute; 1994.
6. Holm LW, Carroll LJ, Cassidy JD, et al. The burden and determinants of neck pain in Whiplash associated disorders after traffi c collisions, results of the Bone and Joint Decade 2000–2010 Task Force on Neck pain and its Associated Disorders. Spine. 2008; 33(4 Suppl): S52–S59
7. Jansen GB, Edlund C, Grane P, et al. The Swedish Society of Medicine and the Whiplash Commission Medical Task Force. Whiplash injuries: diagnosis and early management. Eur Spine. 2008; J 17(Suppl 3): S359–S418
8. Bogduk N. The anatomy and pathophysiology of whiplash. Clin Biomech. 1986;1:92-101.
9. Winkelstein A, McLendon RE, Barbir A, et al. An anatomic investigation of the cervical facet capsule quantifying muscle insertion area. J Anat 2001;198:455-461. 
10. Penning L. Acceleration injury of the cervical spine by hypertranslation of the head: Part I Effect of normal translation of the head on cervical spine motion: A radiologic study. Eur Spine J. 1993;1:7-12.
11. Brault JR, Siegmund GP, Wheeler JB. Cervical muscle response during whiplash: Evidence of a lengthening muscle contraction. Clin Biomech. 2000;15:426-435.
12. Panjabi MM, Cholewicki J, Nibu K, et al. Mechanism of whiplash injury. Clin Biomech. 1998;13:239-249. 
13. Örtengren T, Hansson HA, Lövsund P, et al. Membrane leakage in spinal ganglion nerve cells induced by experimental whiplash extension motion: A study of pigs. J Neurotrauma. 1996;13:171-179. 
14. Brault JB, Wheeler JB, Siegmund GP, et al. Clinical response of human subjects to rear-end automobile impacts. Arch Phys Med Rehab. 1998;79:72-80. 
15. Lord SM, Barnsley L, Wallis BJ, et al. Chronic cervical zygapophysial joint pain after whiplash, A placebo-controlled prevalence study. Spine. 1996;21:1737-1745. 
16. Falla D, Bilenkij G, Jull G. Patients with chronic neck pain demonstrate altered patterns of muscle activation during performance of a functional upper limb task. Spine. 2004; 29, 1436-1440
17. Nederhand MJ, Hermens JH, IJzerman MJ, et al. Chronic neck pain disability due to an acute whiplash injury. Pain. 2003; 102, 63-71.
18. Macnab I: Acceleration extension injuries of the cervical spine. Rothman and Simeone. The Spine. 1982.
19. Evans RW. Some Observations on Whiplash Injuries. Neurol. Clin. 1992; Vol. 10, 975-997.
20. Sterner Y, Gerdle B. Acute and chronic whiplash disorders—A review. J. Rehabil. Med. 2004; 36, 193-209.
21. Binder A. The diagnosis and treatment of nonspecific neck pain and whiplash. Eura Medicophys. 2007; 79-89.
22. Sterling M. Balancing the ’Bio’ with the psychosocial in whiplash associated disorders. Manual Therapy. 2006;180-181.
23. Ferrari R, Schrader H. The late whiplash syndrome: a biopsychosocial approach. J. Neurol. Neurosurg. Psychiatry. 2001; 70, 722-726.24.
24. Ferrari R. Prevention of chronic pain after whiplash. Emerg Med J. 2002;19(6):526-530.