Cervical Strain (Whiplash) 

Updated: Dec 02, 2019
Author: Warren Magnus, DO; Chief Editor: Trevor John Mills, MD, MPH 

Overview

Practice Essentials

Cervical strain (sprain of the ligaments of the cervical spine) is a common injury routinely seen in the emergency department (ED). A cervical strain is chiefly the result of a stretch injury to the muscular and ligamentous elements of the cervical spine. Frequently the result of trauma from falls or motor vehicle accidents (MVAs), this condition causes much distress to patients, but with appropriate management, it usually has few long-term sequelae. High-speed injury mechanisms have brought the common term whiplash into use to describe these injuries, as well as the more inclusive whiplash-associated disorders (WAD).[1, 2, 3, 4, 5]

(See the images below.)

Radiograph of the cervical spine shows a normal lo Radiograph of the cervical spine shows a normal lordotic curve.
Radiograph of the cervical spine shows straighteni Radiograph of the cervical spine shows straightening of the lordotic curve.

Cervical strain is very common, with as many as one million cases per year from high-velocity (whiplash-type) injuries alone. The incidence of whiplash injury ranges from 16 to 200 per 100,000 population. Typically, adults are more commonly affected than children. MVA injury mechanisms more commonly affect adults because of differences in safety requirements and in seat fit (ie, child safety seats generally provide better support of the cervical spine than typical automobile seats).[6]

Occupational cervical spine injuries are common and can afflict not only individuals involved in physical labor but also people in primarily desk or office positions, with modern office conditions and ergonomics having significant impact on susceptibility.

Diagnosis

The chief diagnostic challenge in the emergent or urgent setting is to differentiate cervical strain from other causes of neck pain. All posttrauma patients with cervical pain should be "clinically cleared" using National Emergency X-Radiography Utilization Study (NEXUS) or the Canadian C-Spine Rule as decision rules to guide the use of cervical spine radiography to rule out cervical fractures, dislocations, or spinal cord injury.[7, 4, 5, 8]

Edema of cervical tissues, although not to the point of pitting, is a common finding in patients with cervical strain. The most common presentation is a palpable bogginess of the cervical posterior musculature. 

Where radicular symptoms are present, the Spurling Maneuver (compression of the cervical spine by downward pressure) can be useful. In a systematic review, the Spurling maneuver showed high specificity ranging from 0.89 to 1.00 (95% confidence interval [CI]: 0.59-1.00) and sensitivity ranging from 0.38 to 0.97 (95% CI: 0.21-0.99) for the diagnosis of cervical radiculopathy.[9]

Radiologic studies are often not indicated acutely in the management of cervical strain. However, given the catastrophic sequelae of cervical spinal cord injury, many emergency physicians have a low threshold for ordering cervical spine radiographs in patients with blunt trauma. 

Treatment

In the ED, apply ice to acute strain injuries, and administer analgesia and pain control, as well as muscle relaxants. Outpatient medications should include acetaminophen or an NSAID. Muscle relaxant medications may be considered adjunctive care.

Follow-up with a primary care physician is strongly recommended in cervical strain injuries to facilitate further care. For patients involved in occupational injuries, appropriate referral for follow-up is particularly important.

Pathophysiology

A cervical strain is chiefly the result of a stretch injury to the muscular and ligamentous elements of the cervical spine, although some compressive forces can be involved as well, depending on the exact mechanism of injury. Such injury can occur acutely, as in a motor vehicle accident, or the injury can occur over time; repetitive stress injuries to the cervical spine are common and can be difficult to differentiate from other myofascial syndromes affecting the cervical and upper thoracic region. Additionally, a significant number of injuries to the cervical spine can result from abnormal posture. Such injuries can result from occupational situations that result in odd positioning of the neck to overnight sleep positioning–related injuries.

Lateral view of the muscles of the neck. Lateral view of the muscles of the neck.
External craniocervical ligaments. External craniocervical ligaments.
 

Presentation

History

The most important issues surrounding cervical spine injury involve accurate diagnosis. Emergency departments in the United States and Canada annually treat more than 13 million patients with trauma who are at risk for cervical spine injury. Although most of these cases represent soft tissue injury, the paramount concern for the emergency medicine physician is to identify the patients with fractures, dislocations, or spinal cord injury.

Ascertainment of the mechanism of injury is essential. This postinjury analysis can give significant clues to the relative risk of strain versus a more serious cervical spine injury. The greater the amount of force experienced by the cervical spine, the greater the risk of destabilizing injury and the need to rapidly eliminate more severe diagnoses.

Pain is the most common complaint reported in cervical spine injuries. Severity of discomfort with cervical strains is typically low, although some patients may report significant pain, particularly with motor vehicle injury mechanisms.

Soft tissue swelling is a highly variable finding but can cause significant distress to patients presenting with cervical spine strain injuries. Self-reported tenderness may be noted on the patient’s history. Following a cervical strain injury, patients may report varying degrees of muscle spasms.

Reported range of motion of the cervical spine is important to diagnosis because patients who are able to voluntarily move their cervical spine can help the examining physician to clinically eliminate certain more significant cervical spine injuries and conditions. All posttrauma patients with cervical pain should be "clinically cleared" using National Emergency X-Radiography Utilization Study (NEXUS) or the Canadian C-Spine Rule as decision rules to guide the use of cervical spine radiography to rule out cervical fractures, dislocations, or spinal cord injury.

Radicular pain patterns can occur in cervical spine injuries of all types and do not necessarily eliminate strain injuries from the differential.

Physical

Fracture, dislocation, or ligamentous instability must be eliminated by examination or diagnostic imaging. Edema of cervical tissues, although not to the point of pitting, is a common finding in patients with cervical strain. The most common presentation is a palpable bogginess of the cervical posterior musculature. Tissue texture changes beyond edema are also commonly present (eg, ropiness, tightness, increased muscle tension).

Mild warmth over the involved tissues is not uncommon and is the result of inflammation of the involved tissues.

Limited range of motion of the involved area is often the result of muscle spasm and is not necessarily reflective of the severity of the injury. However, all patients with a significant reduction of range of motion should be considered for cervical spine radiographs.

Where radicular symptoms are present, the Spurling Maneuver (compression of the cervical spine by downward pressure) can be useful. In a systematic review, Spurling's maneuver showed high specificity ranging from 0.89 to 1.00 (95% confidence interval [CI]: 0.59-1.00) and sensitivity from 0.38 to 0.97 (95% CI: 0.21-0.99) for the diagnosis of cervical radiculopathy.[9]

Reproduction of the radicular symptom with compression suggests encroachment on the nerve by arthritic change or disk herniation rather than a muscular or ligamentous strain.

The Quebec Task Force on Whiplash-Associated Disorders, as part of their consensus document, proposed the following grading system[10, 11] :

  • Grade I - Complaint of neck stiffness only with no associated findings

  • Grade II - Complaint of neck pain with physical findings such as palpable tenderness or reduced range of motion

  • Grade III - Complaint of neck pain with physical findings and objective neurologic findings such as reduced muscle strength or deep tendon reflexes

  • Grade IV - Adds radiologic changes such as fracture or dislocation and no longer falls within the realm of cervical strain

Causes

The causes of cervical strain injuries can be divided into general categories based on injury speed. Rapid injury can occur due to traumatic mechanisms that result in rapid whipping of the head on the neck (hence the common term whiplash), such as motor vehicle accidents, falls, sports injuries, or assault.

Low-velocity injuries can be more elusive in their precise mechanism and can vary from acute to chronic in their presentation. Strained cervical postures (eg, painting overhead, sitting in the front row at the movies) are common. Chronic strains (eg, using the neck to hold the telephone, other malposition syndromes) and repetitive motion injuries are often easier for the patient to pinpoint.

 

DDx

 

Workup

Imaging Studies

Radiologic studies are often not indicated acutely in the management of cervical strain. However, given the catastrophic sequelae of cervical spinal cord injury, many emergency physicians have a low threshold for ordering cervical spine radiographs in patients with blunt trauma. However, the literature supports that very few of these patients actually have a cervical spine fracture, and the past pattern of use of radiography has not been efficient. While cervical spine radiography is a low-cost procedure, it adds substantially to overall healthcare costs given the high volume of its use, in addition to leading to considerable discomfort for patients immobilized by a backboard and hard collar while awaiting radiography.

Clinical evaluation and history have been proven effective in guiding the need for radiography to further evaluate patients with possible clinically significant cervical spine injury. The National Emergency X-Radiography Utilization Study (NEXUS) Low-Risk Criteria (NLC) state that cervical spine radiography is indicated for patients with trauma unless they meet all of the following 5 criteria[7, 4, 5, 8] :

  • No posterior midline cervical spine tenderness

  • No evidence of intoxication

  • A normal level of alertness

  • No focal neurologic deficit

  • No painful distracting injuries

The Canadian C-Spine Rule was designed in 2001 to help assess the need for imaging in people who present to the ED with a cervical spine injury after blunt trauma. It was developed for use in adults who are alert (score of 15 on the Glasgow Coma Scale) and stable and in whom a clinically important cervical spine injury is a concern. The Canadian C-Spine Rule is based on 3 high-risk criteria (age ≥65 years, dangerous injury mechanism, paresthesia in extremities), 5 low-risk criteria (simple rear-end motor vehicle collision, sitting position in the ED, ambulatory at any time, delayed onset of neck pain; absence of midline cervical-spine tenderness), and the ability of the person to rotate the neck.[7, 4, 5, 8]

High-speed helical CT technology has made it possible to rapidly perform cervical spine CT with reconstruction and is an efficient and cost-effective method of screening for cervical injury in high-risk trauma patients. For high-risk patients, severe head injury, high-energy injury mechanism of motor vehicle collision, victims of motorcycle collision, and pedestrians struck by automobiles, CT has higher sensitivity than plain films in the detection of fractures, with less chance of a missed fracture leading to severe neurologic injury, such as paralysis. Furthermore, CT is a cost-effective initial screening strategy in patients with high risk of injury, neurologic deficits, or severe head injury when long-term time-frame costs are considered.

Computed tomography has been found to be effective in the detection of clinically significant cervical spine injuries in adults with a neurologic deficit or cervical spine pain. In one study, the sensitivity and specificity of CT for detecting cervical spine injury was 90.9% and 100%, respectively. For clinically significant cervical spine injuries, the sensitivity was 100% and specificity was 100%.[12, 13, 14, 15, 16, 17]

MRI is generally more effective in evaluating spinal cord and ligamentous injury. In the setting of multiple injury, negative findings on CT scans and lateral plain film still warrant an MRI to eliminate instability. In patients who are obtunded or difficult to examine or in patients with persistent focal neurologic deficits or radicular pain, MRI may be necessary to rule out cord injury. MRI is also indicated in patients if new neurologic symptoms develop after the patient's initial presentation to the ED. Although CT with reconstruction is highly sensitive for clinically significant cervical injury, subsequent MRI can confirm significant ligamentous injury.[14, 15, 18]

Even with a normal static radiologic evaluation, a second assessment must be made in high-risk patients to ensure there is no ligamentous instability iand to assess the risk of myelopathy developing from a destabilizing cervical injury. Muscle spasm and limited range of motion secondary to pain after an injury of significant mechanism can hide an anterior subluxation and unstable ligamentous injury. Further radiographic evaluation with dynamic flexion/extension radiography should be arranged on an outpatient basis within 1 week of injury in patients with continued pain or tenderness.

 

Treatment

Emergency Department Care

All persons involved in motor vehicle accidents who sustain neck injuries should, at a minimum, receive cervical collars prior to transport. Many emergency medical service (EMS) protocols require these patients to be placed on a backboard in full spinal precautions. Because MVAs often involve enough force to seriously injure the cervical spine, such precautions are essential to prevent further injury.

In the ED, apply ice to acute strain injuries, and administer analgesia and pain control, as well as muscle relaxants. Outpatient medications should include acetaminophen or an NSAID. Muscle relaxant medications may be considered adjunctive care.

Soft collars are commonly used but have not been proven effective.[19, 1, 2, 20]

A single-blind study with 6-month follow-up conducted by Borchgrevink et al found that patients who received "usual care," with early mobilization and pain control, fared better than similarly treated patients placed in soft collars.[21] This was reinforced by Kongsted et al.[22]

There have been various calls for early multidisciplinary management, including aggressive early physical therapy and other modalities. Current consensus, however, shows that consultations are rarely required for strain injuries; however, follow-up with a physician familiar with rehabilitation therapies is essential for longer-term management, particularly for patients who have experienced an occupational injury.

Follow-up with a primary care physician is strongly recommended in cervical strain injuries to facilitate further care. For patients involved in occupational injuries, appropriate referral for follow-up is particularly important.

The cohort study by Pape et al in the European Journal of Pain, suggests that initial conservative management is associated with a better long-term outcome than overly aggressive, multidisciplinary approaches.[23]  Therefore, limiting follow-up to primary care referral only and avoiding other interventions such as chiropractic care my be most appropriate.

If additional treatments are to be considered, therapeutic massage appears to have little benefit in the management of strain injuries.[24, 25] Strain/counterstrain manual medicine techniques have been shown to relieve pain in cervical injuries when compared with sham techniques and may be adjunctive in the management of cervical strain.[26, 27]

Regardless of whether the patient is referred, vigilance for decreased function secondary to disuse or long-standing injury should be maintained to prevent long-term sequelae from the strain injury.

Long-term complications of strain injuries are typically related to decreased function secondary to disuse.

Patients who fail to recover experience diffuse somatic, musculoskeletal, and anxiety symptoms. An awareness of these factors can assist in identifying and planning appropriate treatment for these individuals.[28]

Patients with cervical strain injuries who are compliant with recommended therapy, including rest, ice, and physical therapy or exercise programs, often make full, rapid recoveries.  However, only 50% of individuals experience full recovery; approximately 25% continue to experience persistent moderate to severe pain and disability; and 25% have milder levels of pain and disability.[29]

A meta-analysis found predictors of poor outcome after acute whiplash injury are early pain, postinjury anxiety, and catastrophizing, whereas physical factors such as imaging findings and motor dysfunctions are not associated with the outcome of acute whiplash.[3]

Prior to discharge from the ED, patients should be made aware of the potential for long-term injury due to noncompliance.

Patients should be advised of the benefits of ice versus heat in acute injuries.

Patient education in basic exercises can enhance mobility and minimize discomfort during the recovery period.

During follow-up visits, referral to a physical therapist for patients with markedly decreased range of motion or long-standing injury prior to presentation can be significantly beneficial in regaining range of motion as well as strengthening cervical musculature.[30]

 

Medication

Medication Summary

The pharmacology of cervical strain involves pain control and palliation. Nonsteroidal anti-inflammatory drugs (NSAIDs) and acetaminophen are mainstays of therapy. Muscle relaxants may prove valuable when treating severe strain injuries to reduce pain and muscle contracture.

One randomized control trial found no benefit in adding cyclobenzaprine to standard ibuprofen therapy.[19]

Analgesics

Class Summary

For minor strain injuries, oral outpatient analgesics provide adequate pain control. OTC medications also may suffice.

Acetaminophen (Tylenol, Panadol, Aspirin Free Anacin)

Rapidly absorbed from GI tract and distributed widely to all body tissues. Serum half-life is 1-3 h but may be altered in impaired liver function. Posthepatic metabolites excreted in urine.

Nonsteroidal anti-inflammatory agents

Class Summary

NSAIDs control mild to moderate pain and decrease inflammatory reactions. This entire family of medications may ease pain in strain injuries. Tailor dosage on an individual basis.

Ibuprofen (Ibuprin, Advil, Motrin)

Rapidly absorbed orally and distributed widely through body tissues. Serum half-life is 1.8-2 h. Rapidly metabolized and excreted in urine. Complete clearance of single dose occurs in approximately 24 h.

Ketorolac (Toradol)

Provides effective control of moderate to severe pain, with higher potency than other NSAIDs, which results in more marked GI upset, platelet inhibition, and renal effects.

Muscle relaxants

Class Summary

These agents provide adjunctive therapy to allow rest, control pain, and aid physical therapy for musculoskeletal injury.

Orphenadrine citrate (Norflex)

Action not well understood, but its analgesic properties make it clinically effective for muscular injury.

Cyclobenzaprine hydrochloride (Flexeril)

Centrally acting skeletal muscle relaxant structurally related to TCAs with similar liabilities. Can be useful adjunct to other therapies for acute musculoskeletal pain.