Whiplash Associated Disorders

Original Editor - Hannah Norton

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Definition/Description

The term "whiplash" injury was first coined in 1928 to define acceleration-deceleration injuries occurring to the cervical spine or neck region. and later modified to an all-encompassing term known as whiplash-associated disorders (WAD). These clinical entities have been refined to describe any collection of neck-related symptoms following a motor vehicle accident (MVA). The difficulty that remains in describing these injuries is secondary to the fact that there is, by definition, no structural pathology identified following a comprehensive diagnostic workup hence WADs remain a diagnosis of exclusion.

• Treatments include rest, analgesia, soft braces, and early physical therapy.
• The injury may be acute with full recovery or may be chronic with residual long term pain, disability, and health care resource utilization
• WAD is a good example of a medical condition where there is often an apparent disconnect between the magnitude of injury and the magnitude of disability.

Clinically Relevant Anatomy

Whiplash and whiplash-associated disorders (WAD) affect a variety of anatomical structures of the cervical spine, depending on the force and direction of impact as well as many other factors. Causes of pain can be any of these tissues, with the strain injury resulting in secondary oedema, haemorrhage, and inflammation:

• joints: zygapophyseal joints, Atlanto-axial joint, Atlanto-occipital joint
• intervertebral discs and cartilaginous endplates
• muscles
• ligaments: Alar ligament, Anterior atlanto-axial ligament, Anterior atlanto-occipital ligament, Apical ligament, Anterior longitudinal ligament, Transverse ligament of the atlas
• bones: Atlas, Axis, vertebrae (C3-C7)
• nervous systems structures: nerve roots, spinal cord, brain, sympathetic nervous system
• the vascular system structures: internal carotid and vertebral artery
• adjacent joints: Temporomandibular joint, thoracic spine, ribs, shoulder complex
• the peripheral vestibular system

Pathology

Most WADs are considered to be minor soft tissue-based injuries without evidence of fracture. 

The injury occurs in three stages with a rapid loss of lordosis.  

• Stage 1: the upper and lower spines experience flexion in stage one
• Stage 2: the spine assumes an S-shape while it begins to extend and eventually straighten to make the neck lordotic again.
• Stage 3: shows the entire spine in extension with an intense sheering force that causes compression of the facet joint capsules.

Studies with cadavers have shown the whiplash injury is the formation of the S-shaped curvature of the cervical spine which induced hyperextension on the lower end of the spine and flexion of the upper levels, which exceeds the physiologic limits of spinal mobility. 

The Quebec task force proposed a classification system to define the severity of the whiplash injury. 

1. Grade 1 the patient complains of neck pain, stiffness, or tenderness with no positive findings on physical exam. 
2. Grade 2 the patient exhibits musculoskeletal signs including decreased range of motion and point tenderness.   
3. Grade 3 the patient also shows neurologic signs that may include sensory deficits, decreased deep tendon reflexes, muscle weakness.
4. Grade 4 the patient shows a fracture.  

Severe Lesions

• Hyperextension and distraction of the neck may rupture the anterior longitudinal ligament and also some discs.
• Pure hyperextension may also lead to compression of the spinal cord in those cases where retrolisthesis or spinal stenosis already existed.
• Hyperflexion injury may lead disruption of posterior ligaments and occasionally facet joint luxation and/or to fractures of the vertebral body (most fractures of the atlas and of the axis are the result of motor vehicle accidents).
• Less likely, lesions of veins, arteries, neural structures, oesophagus and retropharyngeal tissues may occur.

Other Lesions

Less severe lesions which may involve the intervertebral discs, the zygapophyseal joints, the cervical ligaments and muscles are much more frequent. These lesions may occur in isolation but are more often combined and therefore are sometimes difficult to recognize. The common complaint is neck pain.

Etiology

Whiplash-associated disorders describe a constellation of neck-related clinical symptoms manifesting after an MVA or car crash-related mechanism.  The pathophysiologic cascade remains poorly understood and ultimately elusive. 

Speculated underlying mechanisms had causing symptoms consistent with WADs are multifactorial elements eg. vertebral distraction to the facet joint capsule region of the cervical spine causing pain, minor injuries to either the facet joint(s), spinal ligaments, dorsal root ganglia/nerve roots, intervertebral discs, cartilage, and paraspinal muscle spasms or contusions of the intraarticular meniscus.

Epidemiology

As of 2018, whiplash injuries are estimated to affect 0.3% of people a year in the US sustained during sporting injuries, falls, and most commonly motor vehicle accidents. 

• Approximately 1 million people suffer from a whiplash-associated disorder from a motorcycle accident each year. 
• Before the introduction of seatbelts in 1990 in the UK, the rate was 42.5% of patients seen for automobile collisions with neck injuries.
• British Columbia reported that 61% of claimants to insurance companies were for neck claims in 1995. 
• The incidence is higher in women with females representing almost two-thirds of the population. 

There is little consistency in the literature regarding epidemiology partially because of poor quality studies compounded by the complex interconnection of other factors including individual, legal, and socioeconomic factors that may influence outcomes

The risk that patients develop WAD after an accident with acceleration-deceleration mechanism of energy transfer of the neck depends on a variety of factors:

• severity of the impact, however, it is difficult to obtain objective evidence to confirm this.
• neck pain present before the accident is a risk factor for acute neck pain after collision.
• women seem to be slightly more at risk of developing WAD.
• Age is also important; younger people (18-23) are more likely to file insurance claims and/or are at greater risk of being treated for WAD.

The number of people worldwide who suffer from chronic pain is between 2 and 58% but lies mainly between 20 and 40%.

• If a patient still has symptoms 3 months after the accident they are likely to remain symptomatic for at least two years, and possibly for much longer.
• 50% of people with injury from whiplash will have a full recovery,
• 25% may have mild levels of disability and the rest moderate to severe pain and disability

There are many prognostic factors that determine the evolution of WAD and the likelihood that it will evolve into chronic pain.

• Pre-collision self-reported unspecified pain, high psychological distress, female gender and low educational level predicted future self-reported neck pain.
• no postsecondary education, older age, female gender, history of previous neck pain, baseline neck pain intensity greater than 55/100, presence of neck pain at baseline, presence of headache at baseline, catastrophising, WAD grade 2 or 3, and no seat belt in use at the time of collision.
• If the patient was out of work before the accident, sick-listed, or had social assistance, this can also be associated with a negative evolution following whiplash trauma. Illness notification before the accident can also be associated with neck pain in the future.
• Baseline disability has a strong association with chronic disability, but psychological and behavioural factors are also important.
• Cold pain threshold, neck ROM, headache, posttraumatic stress symptoms, hyperarousal symptoms (PDS), initial high Neck Disability Index (NDI)

Whiplash Clinical Prediction Rule

A Clinical Prediction Rule (CPR) is a tool that helps to predict the outcome, for example, the possibility of a person to have moderate/severe pain and disability or have full recovery after a whiplash injury. CPRs are used mostly in the following circumstances:

• complex decision-making
• uncertainty
• cost-saving possibilities with no compromise to patient care

According to Howell, chronic neck pain following a whiplash-type injury could be predicted with the use of the Neck Disability Index (NDI). She found correlations with pain, disability and driving task scores with whiplash-associated disorder (WAD) patients. Also, she reported that active cervical range-of-motion (CROM) reductions were common and important clinical outcome measures related to the clinical prognosis of neck disability

The CPR for WAD suggests the following:

• Probability for chronic moderate/severe disability with older age (≥35), initial high levels of neck disability (NDI≥40) and symptoms of hyperarousal
• Probability for full recovery with younger age (≤35) and initial low levels of neck disability (NDI≤32)

Clinical Prediction Rule Algorithm

Ritchie et al found this CPR to be reproducible and accurate when used following whiplash due to a motor vehicle collision

Clinical Presentation

Whiplash-associated disorder is a complex condition with varied disturbances in motor, sensorimotor, and sensory functions and psychological distress. The most common symptoms are sub-occipital headache and/or neck pain that is constant or motion-induced. There may be up to 48 hrs delay of symptom onset from the initial injury.

Motor Dysfunction

• One of the most common clinical characteristics is a restricted range of motion of the cervical spine. This finding may reflect underlying disturbances in motor function due to the initial peripheral nociceptive input caused by injured anatomical cervical structures. Further research of such potential mechanisms in WAD is necessary.
• Another characteristic is altered patterns of muscle recruitment in both the cervical spine and shoulder girdle regions. This is clearly shown to be a feature of chronic WAD.
• Mechanical cervical spine instability

Sensorimotor Dysfunction

• Loss of balance
• Disturbed neck influenced eye movement control
• Sensorimotor dysfunction is greater in patients who also report dizziness due to the neck pain.

Sensory Dysfunction: Sensory Hypersensitivity to a Variety of Stimuli

• Psychological distress
• Post-traumatic stress
• Concentration and memory problems
• Sleep disturbances
• Anxiety
• Depression is common in WAD patients. There are different types we can distinguish:
  • Initial depression: this can be associated with greater neck and low back pain severity, numbness/tingling in arms/hands, vision problems, dizziness, fracture
  • Persistent depression: this can be associated with older age, greater initial neck and low back pain, post-crash dizziness, anxiety, numbness/tingling, vision and hearing problems

Degeneration of Cervical Muscles

• Neck stiffness
• Fatty infiltrate may be present in the deep muscles in the suboccipital region and the multifidi may account for some of the functional impairments such as: Proprioceptive deficits, Balance loss, Disturbed motor control of the neck

Other Symptoms

The following symptoms may also occur

• Tinnitus
• Malaise
• Disequilibrium/Dizziness
• Thoracic, temporomandibular, facial, and limb pain

It is important to carry out thorough spinal and neurological examinations in patients with WAD to screen for delayed onset of the cervical spine instability or myelopathy. Whiplash can be an acute or chronic disorder. In acute whiplash, symptoms last no more than 2-3 months, while in chronic whiplash symptoms last longer than three months. Patients with acute WAD experience widespread pressure hypersensitivity and reduced cervical mobility. Various studies indicate that there can be a spontaneous recovery within 2-3 months According to the Quebec Task Force of WAD (QTF-WAD), 85% of the patients recover within 6 months.

In addition, according to a follow-up study by Crutebo et al. (2010), some symptoms were already transient at baseline and symptoms such as neck pain, reduced cervical range of motion, headache, and low back pain, decreased further over the 6 months period. They also investigated the prevalence of depression and found that at baseline this was around 5% in both women and men, whereas post traumatic stress and anxiety were more common in women (19.7% and 11.7%, respectively) compared to men (13.2% and 8.6%). The majority of all reported associated symptoms were mild at both baseline and during follow-up.

Evaluation

The Canadian cervical spine rules or NEXUS criteria are useful for the evaluation of cervical spine injuries in the emergency department. These criteria determine the need for imaging based on the mechanism of injury, physical presentation at the time of the accident, symptomatic presentation in the emergency department, as well as the physical exam. 

• The NEXUS c-spine criteria recommend imaging if there is posterior midline cervical-spine tenderness,  focal deficits,  altered mental status,  intoxication or distracting injuries.
• The Canadian c-spine rules define the need for imaging with patients greater than 65 years of age, dangerous mechanism of injury, paresthesia, midline tenderness, immediate onset of neck pain and impaired range of motion. 

Additional imaging such as MRI may be necessary for abnormal findings on CT to evaluate for cord injury.  Flexion and extension films can help rule out ligamentous injury

Clinical Diagnosis

WAD can be diagnosed based on the mechanism of the injury and clinical presentation of the patient, . There are no specific neuropsychological tests that can diagnose WAD. However, there are several psychological symptoms, as described above, that are associated with WAD. In addition, a whiplash profile has been developed with high scores on sub-scales of somatisation, depression and obsessive-compulsive behaviour in patients with WAD.

Differential Diagnosis

Includes:

• cervical spine fracture,
• carotid artery dissection,
• herniated disc,
• spinal cord injury,
• subluxation of the cervical spine,
• muscle strain,
• facet injury,
• ligamentous injury. 

NB Whiplash is an injury associated with trauma; remote trauma should dictate evaluation for other causes, such as mass, tumor, infection, etc.  

Outcome Measures

• Neck Disability Index
• Visual Analogue Scale (VAS)
• Pain Catastrophizing Scale
• The Whiplash Activity a participation List (WAL)
• Disabilities of the Arm, Shoulder and Hand (DASH) in persistent Whiplash
• SF-36
• Functional Rating Index
• The Self-Efficacy Scale
• The Coping Strategies Questionnaire
• Patient-Specific Functional Scale
• Core Whiplash Outcome Measure
• The Kessler Psychological Distress Scale
• The Impact of Event Scale

Examination

The assessment of individuals with WAD should follow the normal cervical examination.

Subjective

The subjective history should specifically include information about:

• Prior history of neck problems (including a previous whiplash)
• Prior history of long-term problems (injury and illness)
• Current psychosocial problems (family, job-related, financial)
• Symptoms (location + time of onset)
• Mechanism of injury (e.g. sport, motor vehicle)

Outcome Measures

1. General Health Questionnaire (CHQ)
2. Visual Analogue Pain Scale
3. Neck Disability index

Objective

Physical examination is required to identify signs and symptoms and classify WAD according to the QTF-WAD.

Inspection and Palpation

During palpation, stiffness and tenderness of the muscles may be observed. These physical symptoms are present in grade 1, 2 and 3. Trigger points may also be observed in grade 2 and 3 WAD. The number of active trigger points may be related to higher neck pain intensity, the number of days since the accident, higher pressure pain hypersensitivity over the cervical spine, and reduced active cervical range of motion.

ROM Testing

In grade 1 WAD, there are no physical signs, so there will be no decreased ROM. In grades 2 and 3, a decreased ROM can be identified by testing the neck flexion, extension, rotation and 3D movements.

Neurological Examination

To distinguish grade 3 from grade 2, a neurological examination is needed. Patients with grade 3 have symptoms of hypersensitivity to a variety of stimuli. These can be subjectively reported by patients, and may include allodynia, high irritability of pain, cold sensitivity, and poor sleep due to pain.

Objectively, the results of the neurological examination are hyporeflection, decreased muscles force and sensory deficits in dermatome and myotome. These responses may occur independently of psychological distress. Other physical tests for hypersensitivity include pressure algometers, pain with the application of ice, or increased bilateral responses to the brachial plexus provocation test.

Management

• Immobilization with a soft cervical collar, resumption of normal activity, and mobilization exercises are generally the treatment of choice. 
• Immobilization has shown the least improvement 
• Ultrasound has also been shown to relieve muscle pain for whiplash-associated disorders.
• First-line treatments include analgesics, nonsteroidal anti-inflammatories, ice, and heat.
• Other controversial analgesic measures include muscle relaxants, which have been shown to have some therapeutic effect in limited studies. 
• Biofeedback has also demonstrated effectiveness when used in conjunction with other modalities in acute WAD. 
• Injection of lidocaine intramuscularly was also found to relieve pain symptoms. 
• Most treatments alone appeared to have moderate effectiveness with combinations of treatment measures improving efficacy and early mobilization consistently most effective

Physical Management

Management approaches for patients with WAD are poorly researched. Very often these patients do not fit into treatment categories as defined for other cervical pain problems due to multiple factors, and even within the WAD group there are multiple variances which warrant individualised treatment approaches.

Whiplash-associated disorder is a debilitating and costly condition of at least 6-month duration. Although the majority of patients with whiplash show no physical signs, Studies have shown that as many as 50% of victims of whiplash injury (grade 1 or 2 WAD) will still be experiencing chronic neck pain and disability six months later. In most cases, symptoms are short lived. Only a substantial minority goes on to develop LWS (late whiplash syndrome), i.e. persistence of significant symptoms beyond 6 months after injury. Available data suggest that the combination of the injury with psychological factors such as coping style and explanatory style may lead to chronic WAD.

Acute Whiplash

Treatment for acute whiplash can be delayed due to multiple social, economic, and psychological factors. Psychological factors such as depression, anxiety, expectations for recovery, and high psychological distress have been identified as important prognostic factors for WAD patients.

Coping strategies such as diverting attention and increasing activity are related to positive outcomes. Another review with a high evidence level recommends that patients suffering from acute WAD “act as usual” and do early, controlled, physical activity within their tolerance level.

Education provided by physiotherapists or general practitioners is important in preventing chronic whiplash and must be part of the biopsychosocial approach for whiplash patients. The most important goals of the interventions are:

1. Reassuring the patient
2. Modulating maladaptive cognition about WAD
3. Activating the patient

The target of education is removing therapy barriers, enhancing therapy compliance and preventing and treating chronicity.

There is strong evidence that to reduce pain, disability and improve mobility both verbal education and written advice are helpful. According to Meeus et al., in acute patients oral information is equally as efficient as an active exercise program.
In subacute or chronic patients, a programme integrating information, exercises and behavioural programmes, and a multidisciplinary programme, seem necessary. For more information on this refer to the section on chronic WAD.
In acute whiplash patients, a short oral education session is effective in reducing pain and enhancing mobility and recovery. Different types of education include:

1. Oral Education: there is strong evidence for providing oral education concerning the whiplash mechanisms and emphasising physical activity and correct posture. It has a better effect on pain, cervical mobility, and recovery, compared to rest and neck collars. Furthermore, studies show that oral education could be as effective as active physiotherapy and mobilisation.
2. Educational video: A brief psycho-educational video shown at the patient's bedside seems to have a profound effect on subsequent pain and medical utilisation in acute whiplash patients, compared to the usual care.

According to the Whiplash book education and information given to the patient must contain the following information:

• Reassurance that prognosis following a whiplash injury is good.
• Encouragement to return to normal activities as soon as possible using exercises to facilitate recovery
• Reassurance that pain is normal following a whiplash injury and that patients should use analgesia consistently to control this
• Advice against using a soft collar

More studies are required to provide firm evidence for the type, duration, format, and efficacy of education in the different types of whiplash patients

Future research should be founded on sound adult learning theory and learning skill acquisition.

Different types of exercise can be considered for WAD, including ROM exercises, McKenzie exercises, postural exercises, and strengthening and motor control exercises. It is not clear which type of exercise is more effective or if specific exercise is more effective than general activity or merely advice to remain active.

Active treatment which consists of early active mobilisation that is applied gently and over a small ROM, and which is repeated 10 times in each direction every waking hour seems to be as effective at reducing the pain after the whiplash injury as on ROM. This exercise can also be given as homework.

In a randomised study by A. Söderlund et al., where the aim was to compare two different home exercise programs in acute WAD, the result was that a home exercise programme, including training of neck and shoulder ROM, relaxation and general advice, seems to be sufficient treatment for acute WAD patients when used on a daily basis.

Supported by several high and low-quality studies, evidence-based therapy for acute WAD consists of early physical activity, mobilisation and education.

From this, we can conclude that there is strong evidence to suggest that exercise programs and active mobilisation significantly reduce pain in the short term and there is evidence that mobilisation may also improve ROM.

Spinal manual therapy is often used in the clinical management of neck pain. It is not easy to tease out the effects of manual therapy alone because most studies used it as part of a multimodal package of treatment.

Systematic reviews of the few trials that have assessed manual therapy techniques alone concluded that manual therapy, such as passive mobilisation, applied to the cervical spine may provide some benefit in reducing pain, but that the included trials were of low quality.

Patients with grades 1 and 2 2 WAD showed good results in a multimodal treatment program including exercises and group therapy, manual therapy, education and exercise. At their 6 months follow-up, 65% of subjects reported a complete return to work, 92% reported a partial or complete return to work, and 81% reported no medical or paramedical treatments over 6 months

For the early management of WAD grades 1 and 2, general practitioner care includes advice to stay active and resumption of regular activities.

The synthesis of DA Sutton et al. suggests that patients receiving high-intensity health care tend to experience poorer outcomes than those who receive fewer treatments for WAD and NAD.

Another interesting topic is the use of a collar. The use of a collar stands in contrast with what is indicated in most of the studies; activation, mobilisation and exercise. In a randomised study of Bonk et al. subjects were randomly assigned to a collar therapy group or to the exercise group. During a one week period participants had to record their average pain and disability in a diary, using the VAS scale. The results showed a significant difference between the groups, with positive effects on the prevalence of symptoms in the exercise therapy group compared to the collar group at six weeks. It is proven that early exercise therapy is superior to collar therapy in reducing pain intensity and disability for whiplash injury. Other studies also showed that exercise therapy gives better pain relief than a soft collar.

Chronic Whiplash

There is a difference between a patient suffering from acute whiplash and a patient suffering from chronic whiplash. There is a suggestion that the injury in combination with psychological factors may lead to chronic WAD.

A multidisciplinary therapy with cognitive, behavioural therapy and physical therapy, including neck exercises is effective in the management of WAD patients with chronic neck pain

When behavioural therapy is used in the therapy, it decreases the patient’s pain intensity in problematic daily activities. Therefore functional behavioural analyses can be used to adapt planning and treatment.

There is evidence that exercise programs have a positive result in reducing pain in the short term. Exercise programmes are the most effective noninvasive treatment for patients with chronic WAD, although many questions remain regarding the relative effectiveness of various exercise regimens. There is also evidence suggesting that coordination exercises should be added to the treatment to reduce neck pain.

Multidisciplinary therapy gives positive results according to the reductions of neck pain and sick leave reported.

This is also the therapy recommended by the Dutch clinical guidelines for WAD.

In patients with chronic WAD, negative thoughts are a very important factor. Self-efficacy, a measure of how well an individual believes he can perform a task or specific behaviour and emotional reaction in stressful situations, was the most important predictor of persistent disability in those patients.

Negative thoughts and pain behaviour can be influenced by specialists and physical therapists by educating patients with chronic WAD on the neurophysiology of pain. Improvement in pain behaviour resulted in improved neck disability and increased pain-free movement performance and pain thresholds according to a pilot study.

Michaleff et al. even found that simple advice is equally as effective as a more intense and comprehensive physiotherapy exercise programme.

In a case report of Ferrantelli J.R.et al., the patient underwent a Clinical Biomechanics of Posture Rehabilitation in which he received mirror-image cervical spine adjustments, exercises and traction to reduce head protrusion and cervical kyphosis. The first ten visits included regional bilateral long-lever cervical spinal manipulation to temporarily decrease pain and increase ROM, and thereafter the structural rehabilitation care started. This treatment consisted in mirror-image drop table adjustments, mirror-image handheld instrument adjustments, mirror-image isometric exercise and mirror-image extension-compression traction for the reduction of the abnormal anterior translation posture of the head. After 5 months, the patient’s chronic WAD symptoms were improved.

As Michaleff et al. say in their article, that we can conclude that an important health priority is the need to identify effective and affordable strategies to prevent and treat acute to chronic whiplash-associated disorders.

Clinical Bottom Line

• For the management of chronic whiplash, there is strong evidence that multidisciplinary therapy is effective. This therapy consists of an exercise program. Early mobilization is most effective when other more serious clinical pathologies noted on examination and imaging diagnostics have been ruled out.
• Prognosis varies secondary to comorbidities prior to the injury, severity of WAD, age and socioeconomic environment.  Full recovery has been shown to occur in a few days to several weeks. However, disability can be permanent and range from chronic pain to impaired physical function.
• Though cervical pain is the most common symptom, dizziness and/or headaches can be chronic, persistently reported symptoms. Chronic pain, subsequent interference with work, and physical function can cause loss of income and lifestyle.
• Diagnosis and treatment of WAD are complex and associated with many complex issues.  Legal environment, prior injury, comorbidity, age, and defensive medicine all play roles in the management and outcomes.  There is a large variation in diagnosis and persistence of symptoms depends largely on legal culture or the ability to seek compensation for WAD.

Resources

In 2017 Walton and Elliot proposed a new Integrated Model of Chronic WAD. This journal article will explain more on this model

Walton DM, Elliott JM. An integrated model of chronic whiplash-associated disorder. journal of orthopaedic & sports physical therapy. 2017 Jul;47(7):462-71.