The winter is truly here to stay for a while and with it comes snow and ice which leads to an increase in car accidents. Chiropractic offices are flooded with car accident cases of whiplash, headaches, and low back pain. Whiplash is the most common injury sustained in a rear end collision because of the forces placed on the cervical spine at the point of impact and the following seconds. Whiplash describes a cervical sprain/strain that occurs when the head and neck are forced into rapid extension from the initial rear impact followed by rapid recoil into flexion. This rapid back and forth motion cause stretching and tearing to the muscles and ligaments of the cervical spine. Chiropractic care incorporates hot/cold therapy, spinal manipulation, stretching, soft tissue work, and physical therapy modalities such as ultrasound, electric muscle stimulation, and traction to treat whiplash injuries. Chiropractors stretch tight muscles in spasm and strengthen weak muscles in order to return balance to the cervical spine. They use gentle spinal manipulations to restore normal range of motion and relieve pain. Chiropractors use physical therapy modalities like ultrasound and electric muscle stimulation to reduce muscle spasm and decrease pain. Special stretches and exercises done at home will help speed up recovery and reduce pain levels. In order to understand whiplash injuries it is important to understand the anatomy and physiology of the neck and the pathophysiology behind muscle strain injuries. This article will cover these topics in detail to better explain whiplash injuries.
The primary muscles of the cervical spine involved in this case are the trapezius, suboccipitals, longus coli, longus capitus, and the levator scapulae. The trapezius is a large superficial muscle that covers the posterior aspect of the neck. The muscle runs from the nucal line on the skull, external occipital protuberance, ligamentum nuchae, and the spinous processes of C7-T12 to the lateral third of the clavicle, acromion, and spine of the scapula. It elevates, retracts, and rotates the scapula when fired and works to stabilize the head in a neutral position. The suboccipital region in the posterior superior aspect of the neck is comprised of 4 sets of muscles. The rectus capitus posterior major travels from the spinous process of C2 to the lateral portion of the inferior nucal line. Rectus capitus posterior minor travels from the posterior tubercle of C1 to the medial portion of the inferior nucal line. The inferior oblique originates from the spinous process of C2 and inserts into the transverse process of C1.
The superior obliques arise from the transverse process of C1 and insert into the occipital bone. These muscles are classified as postural muscles and aid in movement of the atlanto-occipital and atlanto-axial regions. The longus coli and longus capitus are classified as deep neck flexors and are very important stabilizers of the cervical spine. They are found posterior to the deep prevertebral fascia and are considered anterior vertebral muscles. The longus coli muscles arise from the anterior tubercle of C1, bodies of C1-C3, and the transverse processes of C3-C6 and insert into the bodies of C5-T3 and the transverse processes of C3-C5. If working bilaterally it causes neck flexion. If fired unilaterally, it causes neck flexion and contralateral rotation. The longus capitus muscles arise from the basilar portion of the occipital bone and insert into the anterior tubercles of C3-C6 and transverse processes. The main action is to flex the head. The levator scapulae is a thick strap-like muscle that arises from the posterior tubercles of the transverse processes of C1-C4 and inserts into the superior portion of the medial border of the scapula. When fired, it elevates the scapula and tilts the glenoid cavity inferiorly by rotating the scapula.
Upon rear impact, the head is forced into extension causing stretching and tearing of the anterior ligaments and muscles of the neck and impaction of the posterior joints of the neck which include the facets. Posterior elements of the spine, especially the spinous processes, are jammed together and can lead to fracture in severe impacts. As the head then recoils into hyperflexion, the posterior muscles of the spine are stretched and torn and the anterior tissues of the spine including the inervertebral discs are compressed. As a result of this quick stretch, the muscles of the cervical spine go into a reflex spasm in order to stabilize the area. The extent of the muscle strain and/or ligament sprain varies according to the severity of the crash and the amount of force placed into the neck. A cervical strain describes the diagnosis of soft tissue injury to a muscle surrounding the cervical spine and a cervical sprain describes the same type of injury to a ligament. Sprains and strains are classified as grade I, II, or III based on the extent of the injury. A simple grade I strain involves minimal damage to adjacent muscle and ligament fibers (1-10%).
It usually presents with minimal pain, splinting, and palpatory pain. Trigger points may be present and there is a loss in range of motion in the joint. Fixation can occur and joint play can be diminished. A grade II strain involves partial tearing of the muscle or ligament (11-50%) which is often accompanied by hemorrhage and marked splinting. Trigger points and fixation can occur and can present with more severe pain. Grade III strains involve severe tearing of the muscle or ligament (51-100%) and can involve complete rupture of the muscle. It presents with severe pain, hemorrhaging, and ecchymosis resulting in extensive impairment of function. In most cases, whiplash patients experience a slight grade I strain of the cervical musculature resulting in hypertonicity and myospasm.
In more serious rear end collisions a grade II-II sprain/strain can occur and usually requires immediate medical attention and x-rays to rule out fracture and dislocation of the cervical spine. In the case of a grade I sprain/strain, without initial treatment the myospasm will worsen and cause the patient to guard against any movement. This reduces the active range of motion in the cervical spine with can affect flexion, extension, rotation, and lateral flexion. Short term effects can be a reflex increase of tone, fixation, and decreased range of motion. If not treated, long term effects include adhesion formation and degeneration. The etiology of a cervical sprain/strain can be from a number of causes including car accidents, falls, sports injuries, overuse, sustained postural positions, and trauma. Car safety steps can be taken to reduce the chances of serious whiplash injuries. Seat belts should always be properly used with lap and shoulder restraints in the proper position.
When available, steering wheel and door air bags should be activated. The car seat should be in a normal resting position. If the seat is too close to the wheel it can cause severe injury from the deployment of the air bag and increases the risk of head trauma from hitting the windshield. It also increases the chance of knee and hip injury from the impact of the knee into the dashboard. This can cause fracture of the femur, hip, and more commonly the acetabulum within the joint. If the seat is leaned too far back it can cause increase whiplash injuries because the seat belt will not be positioned correctly and can lead to a launching effect of the body. The head piece on the car seat should be elevated so that the back of the skull hits in the middle of the cushioning. If the head piece is too low then the head can hyperextend over the top of the head rest upon the initial rear collision and cause increased injury and even dislocation.