Air Neck Traction

Neck Traction

1. What are the effects of neck traction?

Neck traction is theorized to have several effects. Among these are distraction or separation of the vertebral bodies, a combination of distraction and gliding of the facet joints, tensing of the ligamentous structures of the spinal segment, widening of the intervertebral foramen, alteration of spinal curves, and stretching and relaxing of the muscles.

The generally recognized biomechanical effects of neck traction are to enlarge the intervertebral disc spaces around foramen levels and tighten the posterior longitudinal ligament. One of the main function of the intervertebral disc is to damp the compressive loadings during daily activities. Disc injury or degeneration could lead to mechanical compression or chemical irritation of the nerve root causing neurological deficits. Neck traction is generally regarded as a conservative management in treating various types of neck disorders. Several mechanisms have been proposed for the possible therapeutic effects of traction. DeLacerda et al. (a) reported that the axial traction reduced pain by improving circulation or preventing adhesions and contractures of spinal structures.

By widening the intervertebral disc space and reflecting a stretching of the posterior longitudinal ligaments during neck traction, a suction effect of the negative intradiscal pressure and the pushing effect of the posterior longitudinal ligaments may have a beneficial effect of herniated or protruded discs and has been theorized to positively affect the disc’s nutrition.

Krause et al. concluded that the separation of vertebrae by increasing the diameter of intervertebral foramen could reduce radicular pain and normalize neurological deficits by relieving direct pressure or contact forces in the sensitized neural tissues.

The intervertebral disc space decreases and leads to disc degeneration if the duration and extent of spinal compressive loadings exceeded the physiological set point. The decrease in the intervertebral disc space would constrict the intervertebral foramen sufficiently to cause entrapment or compression of the spinal nerve root. According to Lu et al. a 1 mm narrowing of the intervertebral disc space was reported to correspond to a reduction of 20–30% in the foraminal area. Long-term axial distraction could separate the intervertebral disc space and induce the signs of disc tissue recovery on biological and biomechanical levels according to Kroeber et al.

Chung et al. used an inflatable neck traction device in the sitting position and noted during traction, all volunteers and 21 patients had a substantial increase in the length of the cervical vertebral column. The disc herniation was completely resolved in three patients and partially reduced in 18.

Honet and Puri provided a progressively more intense neck traction treatment, depending on severity of symptoms and neurological findings in patients with radicular symptoms. Subjects received traction treatment at home, in an outpatient facility, or in the hospital. The percentage of patients with excellent or good outcomes was 92% in the home treatment category, 77% in the outpatient treatment category, and 65% in the hospital treatment category.

Wong et al. (a) observed that the traction significantly decreased the electromyographic activity of paraspinal muscles during the whole traction phase. Shirai et al. showed that cervical traction increases blood flow to neck muscles within two minutes after application.

Hattori et al. noted short-latency somatosensory evoked potentials (SSEP) latencies were decreased after cervical traction in patients with radiculopathy and cervical sprain. In patients with severe myelopathy, latencies may increase. Traction may improve conduction by improving blood flow to cervical nerve roots.

Evaluation of 20 minutes of neck traction by computerized tomography, H. Sari et al. documented: Regression of herniated disc area, increase in spinal canal area (11.21 mm2), spinal column elongation between C2 and C7 (l.39 mm) and intervertebral discal space widening at the C5-C6 level. The authors concluded, "Cervical traction has a significant biomechanical effect on spinal structures, which can be demonstrated by CT evaluation before and after traction."

According to Constantoyannis et al. It is probable that traction has an important role in breaking the “circle of pain” in cervical radiculopathy caused by a herniated disc. This cycle begins when nerve roots are compressed by a herniated disk, causing entrapment within the intervertebral foramina. The irritated nerve produces a reflex response to the patient’s cervical muscles, causing those muscles to contract. That contraction further narrows the foramina, and the neck pain is increased. Intermittent traction helps to relieve the inflammatory reaction of nerve roots by improving the circulation to the tissues and reducing swelling of the tissues. Gentle alteration of stretching and relaxation of the neck soft tissue structures prevents the formation of adhesions of the dural sleeve.

2. What are the indications for neck traction?

As related to the above theoretical effects, the indications are (A) herniated disc or radiculopathy, (B) any condition in which mobilization and stretching of soft tissue are desired, and (C) any condition in which opening the neural foramen or widening the disc space is desired.

Traction, by increasing the distance between articular surfaces, may disengage a protrusion that is too large to shift during a standard approach of avoidance of compression during recumbancy and/or cervical collars or with more active measures such as exercise.

3. What are the contraindications for neck traction?

Neck traction is contraindicated in patients with structural disease secondary to tumor or infection, rheumatoid arthritis, severe vascular compromise, and any condition for which movement is contraindicated. Relative contraindications include acute strains and sprains and inflammatory conditions that may be aggravated by traction. Strong traction should not be applied to patients with spinal joint instability. Traction should be avoided if the patient has had recent spinal surgery; the surgeon should be consulted before applying traction if a fusion is less than 1 year old. Other relative contraindications may include pregnancy, osteoporosis, hiatal hernia, and claustrophobia.

4. How much force should be applied for neck traction?

Judovich found that 25 to 45 lb forces were necessary to demonstrate a measurable change in the posterior cervical spine structures. Colachis and Strohm demonstrated that a traction force of 30 lb produced separation of the cervical spine (a), and that a 50-lb force produced more separation than a 30 lb force (b).

If this is your patient’s first trial with neck traction, we suggest you start at a lower level and gradually increase the force over several sessions. Treatment should always be guided by patient tolerance. If radicular symptoms are present, force is directed to the point of reduction, centralization or abatement and, while some post-treatment muscle soreness in the neck is common, too much soreness or an increase in radicular symptoms is a sign that the force may have been increased too quickly. The Air Neck Traction devices give you a wide range of traction forces and you will find that some patients tolerate low levels of force, while others require high levels of traction force generally not available on other neck traction devices. Ultimately, we are not trying to document exact units of force, we are trying to relieve the patients symptoms. We recommend the least amount of force that is adequate to reduce or eliminate the patient's symptoms.

Schlicke et al used 1/3 the patients body weight to achieve 1-2 mm of vertebral separation during neck traction. Lawson and Godfrey used up to 60 pounds of traction for 20 minutes which resulted in a 3.4 mm increased height in the cervical spine. DeSeze and Levernieux used 260 pounds to the cervical spine to obtain a 2mm increased disc space at C5-C7. McFarland and Krusen used up to 100 pounds of traction applied to 63 patients with neck complaints due to osteoartritis. They noted an increased interspinous space of 10.9 mm, 6.5 mm along the posterior margins and 2.8 mm increase along the anterior margins of the vertebral bodies.

According to Cyriax(a), "Reducing cervical disc displacement, maximum traction pull was 140kg [308 lbs] noting the pull on one subject was 100kg [220 lbs]. Strong manual traction showed a 2.5 mm increase of the joint space - almost double the distance noted reduction of disc requires adequate traction force. In 1955 an experiment was made to find out how much pull I exerted when reducing a cervical disc displacement. The maximum was found to be 140kg. Miss Moffatt, then my senior physiotherapist at St Thomas's, reached 100 kg. Radiography was carried out before and during a few seconds' fairly strong manual traction on the neck. It showed that traction increased the joint space by 2.5 mm - in other words, almost doubled the distance between the bones. No wonder cervical disc lesions are not difficult to reduce so long as the traction is adequate."

5. What is the best angle and position for neck traction?

While most recommendations for traction of the neck is in slight or moderate flexion and in the supine position, it should be noted that there is no clear specific protocol in the literature for neck traction. We recommend starting in a sitting, neutral position. Again, as in force of traction, patient tolerance determines parameters used for angulation in neck traction. With Air Neck Traction, the patient may lay supine with the head supported by a pillow, the height of which determines the amount of flexion or extension.

The work of Chung et al. clearly indicates the positive effects regarding disc herniation reduction are noted in a sitting, neutral position with 30 pounds of traction force. Considering the similarity between the device used in the study and our traction device, we feel this is the initial protocol of choice to minmize any adverse reactions. The results of a study by DeLacerda (b) indicated that the electrical activity of the upper trapezius increases as the angle of application of neck traction increased. This implies that the angle of traction should receive consideration when cervical traction is used in the treatment of soft tissue cervical syndromes. While increased angle of traction pull increases cervical vertebral separation, this increase in angle also increases muscle tension, a factor that could aggravate soft tissue injuries.

There are negative effects associated with both extension and flexion during traction. Initiating traction in a neutral position allows the safest method in accomodation of the patient to traction forces.

Excessive neck extension would decrease the posterior disc spaces and the efficacy of traction for improving the available course of nerve roots through neural foramens.

The neck extension vector caused by traction force through mandible could be counteracted by the downward force of head weight due to gravity as in anterior leaning during sitting traction. It has been reported that traction forces with a flexion moment were especially effective on the posterior elements of spinal vertebral column, such as posterior intervertebral discs, apophyseal joints, spinal muscles, and ligaments. The increase in the posterior disc spaces implied that there would be an increase in the tension of posterior annular fibers and posterior longitudinal ligament. The stretching of the posterior annulus might prevent the posterior movement of herniated nuclear materials and reduce the posterior disc bulges. However, clinical caution is suggested because cervical flexion might aggravate an existing tear in the annulus fibrosis, compress the anterior disc part, and cause further extrusion of herniated nucleus pulposus. Neck traction with excessive flexion might not be well tolerated by patients with spinal diseases as noted by Humphreys et al.

Furthermore, Vaughn et al. indicated there was no statistically significant difference in posterior intervertebral separation comparing traction angles of 0° and 30°. It was further discussed, "Increasing the rope angle and flexing the cervical spine may produce undesirable effects to the foramen and soft tissue. The intervertebral foramina enlarge with flexion and narrow with extension. However, research suggests that flexing the cervical spine beyond the straight position (reversal of the lordosis) decreases the space available for the spinal nerves within the intervertebral foramen. As the rope angle increases, the myoelectric activity of the cervical musculature during traction also increases. Muscle contraction could negate the effect of traction and cause a narrowing of the foramina. Subjects with neck pain, positioned at a 0° rope angle, recorded no myoelectric activity as measured by electromyogram."

It should also be noted that according to Wong et al. (b) Separation of facet joint surfaces was found after traction at 15 degrees extension, but not in the neutral or flexion positions. Additionally, Jellad A, et al. indicates "... cervical spine traction in the flexion position does not have a greater effect on the posterior intervertebral space and does not provide superior analgesic efficacy."

Deets et al. noted that the head weight in supine position was eliminated, thereby increasing the efficiency of cervical traction compared to that in the sitting posture. However, Akinbo et al. and Jette et al. reported high cervical myoelectric activity and untoward cardiovascular reactions especially in elderly patients and patients with unstable cardiovascular systems during the supine traction procedure.

It is reasonable to assume the literature indicates that flexion and extension, as well as supine positioning in some individuals, should be used with caution during neck traction. Flexion rope angles and anterior leaning during traction may be used to counteract the extension produced by chin halter units with forces via the mandible. The Air Neck Traction uses a neutral positioning with forces that easily overcome the weight of the head. Through small adjustments in positioning, slight flexion or extension can be made according to individual responses to traction as determined by examination. With ease of use and control, along with the ability to use in a number of settings including sitting and supine, home and clinical, the efficacy of neck traction can be improved with the patient's increased comfort and relaxation. This also avoids some confusion in the literature regarding sitting versus supine traction and flexion rope or pull angles.

According to Cyriax(b),
1) If extension is pain-free and flexion hurts, traction will be comfortable if given in slight extension.
2) If both flexion and extension are painful (or neither) distraction of the joints with the articular surfaces parallel may be tried.
3) When extension is painful and flexion pain-free, the distraction should fall mainly on the the posterior part of the joint with traction in slight flexion.

6. What are the treatment times For neck traction?

As a general rule, the higher the force, the shorter the treatment time.

For treatment of a herniated disc, treatment times should be kept within 5-10 minutes. Intradiscal pressure drops under traction causing a suction force. A subatmospheric pressure is induced when the bones move apart, with a centripetal effect on the contents. Osmotic forces soon equalize the pressure with that of the surrounding tissue and the suction force is lost. The loss of pressure, if continued beyond 10 minutes, may cause fluid to be imbibed into the disc as pressure equalization occurs and the suction effect on the disk protrusion is lost, and it is possible for patients to experience a sudden increase in pain when traction is released.

Traction forces should always be released slowly. With Air Neck Traction, the blocker valves should be released and a comfortable, gradual reduction in pressure will occur. The valves can then be shut and the unit easily inflated again. This provides intermittent traction when needed and at intervals best tolerated by the patient.

In treating large volume herniated discs, Constantoyannis et al. used treatment which involved intermittent traction, that is, traction applied for 45 minutes followed by 15-minute intervals without traction. Patients receive treatment for 6 to 8 hours a day, while they watch television or read a magazine. They recommend that patients use a cervical collar the remainder of the day.

Jellad A, et al. used two 20 minute sessions with a 10 minute resting period between traction applications. The authors noted significant improvements in cervical radiculopathy in patients treated with mechanical traction as opposed to manual traction or standard rehabilitation. Parameters measured were neck pain, radicular pain, perceived disability and analgesic consumption.

For most conditions, 10-20 minute treatment times are generally sufficient. A major benefit of Air Neck Traction is the fact that multiple treatments can be done in a single day within a home setting – this is particularly beneficial for acute and subacute conditions. For chronic conditions where the patient is working, before and after work treatments are desirable, however, with the ease of use and portability of Air Neck Traction, traction during most work conditions can be accomodated. Once the patient’s symptoms are under control, many choose to use it only as needed after a hard day’s work, to control headaches or ease radiculopathy or muscle tension.

7. What are some techniques using Air Neck Traction

The Air Neck Traction allows individual control of right and left sides. According to your exam, traction may be performed in lateral flexion related to centralization of symptoms. Adjusting the layers can afford a rotational component to the lateral flexion. The bulbs have a quick release valve for easy and fast adjustments. Another techniques is to hold the affected arm over the opposite shoulder to reduce neural tension during traction for a medial disc or as indicated by shoulder abduction testing. For a lateral disc, a small weight can be placed in the hand of the affected arm or simply increase the traction force on the affected side. The Air Neck Traction can be used in the sitting or supine position. The supine position can be modified with the use of a pillow or rolled towel under the head to increase or decrease traction angle or, if in a clinical setting, adjusting the headpiece on a compatible table. As improvement is noted, range of motion may be incorporated with traction forces to increase mobility or according to centralization.

The Air Neck Traction should not be confused with similar but cheaper products. Reinforced tubing and thicker inner bladder material affords peace of mind and increased effectiveness over copycat products.

According to Zylbergold and Piper, "In summary, traction should be considered as an efficacious component in the treatment of cervical disorders."

References for Neck Traction