Spinal traction is the process of applying force through body weight, weights, and/or pulleys to draw apart the vertebrae of the spine.
Spinal traction may be indicated when a patient complains of cervical, low back, or radiating pain that is likely caused by a vertebral disc protrusion or degenerative changes. It is used to accomplish one or more of the following purposes: distract (pull apart) vertebral bodies, distract and glide the facet joints, widen the intervertebral foramen (openings to the spinal canal formed by the vertebrae), or stretch spinal musculature. Release of discal pressure and widening of intervertebral space can reduce discal pain and pain caused by impingement of nerves exiting the spinal cord .
In general, traction should not be applied when there is a disease process that reduces the body's tolerance to force. Traction is contraindicated when there is a tumor, infection , vascular disorder, ligamentous instability, osteoporosis , or claustrophobia.
Types of spinal traction include: sustained, intermittent mechanical, manual, positional, auto-traction, and gravity traction. Sustained traction is applied with heavy weights or a mechanical device that apply the force to maintain a constant traction for a time period of one to 30 minutes. Intermittent mechanical traction is more widely used in the United States; it involves the use of a split table and a mechanical device to apply and withdraw force every few seconds. In manual traction, the physical therapist may use the weight of his or her body in applying a traction force to the spine. Manual traction is often used to assess a patient's response to traction, or when adjustment of the position or amount of force may be needed. Positional traction allows the patient to be positioned to maximize the effect of traction on the suspected causative structure, or to allow the patient to remain in a preferred posture until pain is relieved. Self-traction allows the patient to position him or herself to provide traction with the assistance of gravity. Gravity lumbar traction is administered in one of two ways. Either the rib cage is grasped in a vest, allowing the weight of the legs to provide a traction force; or the ankles or pelvis are grasped, allowing the upper body to exert the traction force.
In order for traction to be effective, the force must be great enough to cause separation at the target spinal segment (s). A wide range of forces, from 30–300% of body weight, has been shown to be effective in studies of lumbar traction; however, a traction force of such large magnitude as 300% may cause damage to the vertebral structures. Thirty percent of body weight has been shown to be effective in reduction of symptoms. For cervical traction, research has shown that 20–45 lb (7.4–16.8 kg) is an effective range for producing separation.
With mechanical lumbar traction, traction harnesses are placed around the patient's pelvis and thorax. The patient then lies on a split table on his or her back, stomach , or side, depending upon the position thought to be optimal for the specific symptoms being treated. The split table allows for minimizing of friction forces. The straps of the harness are hooked to the motorized traction unit that is programmed for the traction force, overall time, and hold/rest periods desired.
For cervical traction, it has been found that patients are able to relax better and forces of gravity interfere less in the supine versus sitting position. To straighten out the normal lordosis and provide a more longitudinal pull, the neck often is flexed to approximately 20–30°, unless treating the joints of the first and second cervical vertebrae. Several types of head halters and devices are available to connect to the traction source.
Before traction is applied, a full evaluation should be done to determine the possible causes of the patient's symptoms and uncover potential contraindications to traction. Physical therapists often use manual traction as part of the evaluation to assess the effects it has on symptoms. It is important that the patient is able to relax when traction is applied, so that muscle guarding does not take place. Modalities such as heat may be used to help with relaxation .
Traction usually is one part of a patient's plan of care. The physical therapist may teach a patient exercises, body mechanics, self-traction, and pain management techniques that should be performed at home between treatment times and after the course of physical therapy is finished.
It is important that the patient reports any adverse reactions or increase in pain after each treatment. Adverse reactions can be more easily avoided by keeping the initial treatment times short (less than 10 minutes) with low force to allow the patient to become accustomed to the procedure.
The desired outcome of traction is the reduction of neurological signs and pain in the neck, back and/or extremities, allowing for return to functional activities. Although clinicians often find favorable results with the use of traction, research with randomized, controlled trials showing statistically significant positive results is still sparse. This may be due in part to lack of good research design and the many factors involved in back pain.
Health care team roles
The physician usually refers the patient to physical therapy for conservative treatment of neck or back pain. The physical therapist examines the patient and makes decisions regarding the appropriate plan of care, which may include traction. The physical therapist determines the specifications for traction and sets up the patient on the apparatus for the first few times, being sure to monitor the patient intermittently. The physical therapist assistant may set up the patient for future treatments, with guidance from the physical therapist regarding duration and force specifications.
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Meszaros, Thomas F., et al. "Effect of 10%, 30%, and 60% Body Weight Traction on the Straight Leg Raise Test of Symptomatic Patients with Low Back Pain." Journal of Orthopedic and Sports Physical Therapy 30 (Oct. 2000): 595–601.
Saunders, H. Duane. "The Controversy over Traction for Neck and Low Back Pain." Physiotherapy 84 (June 1998): 285–8.
Peggy Campbell Torpey, M.P.T.