Effect of pelvic-femoral position on vertebral separation produced by lumbar traction

Developing a clinical prediction rule to identify patients with lumbar disc herniation who demonstrate short-term improvement with mechanical lumbar traction

OBJECTIVE

To develop a clinical prediction rule (CPR) that predicts treatment responses to mechanical lumbar traction (MLT) among patients with lumbar disc herniation (LDH).

METHOD

This study was an uncontrolled prospective cohort study. The subjects included 103 patients diagnosed with LDH for which they underwent conservative therapy. The subjects received MLT for 2 weeks, and the application of any other medication was left at the discretion of the attending physician. The initial evaluation was performed prior to the initiation of treatment. The independent variables from the initial evaluation were imaging diagnosis, Oswestry Disability Index (ODI), Fear-Avoidance Beliefs Questionnaire score, visual analog scale, medical interview, physical examination. The patients whose ODI after 2 weeks of treatment improved by ≥50% of that at the initial evaluation were defined as responders.

RESULTS

Of the 103 subjects, 24 were responders, and the five predictors selected for the CPR were limited lumbar extension range of motion, low-level fear-avoidance beliefs regarding work, no segmental hypomobility in the lumbar spine, short duration of symptoms, and sudden onset of symptoms. For the patients with at least three of the five predictors, the probability of their ODI greatly improving increased from 23.3% to 48.7% compared with the patients without these predictors (positive likelihood ratio, 3.13).

CONCLUSION

Five factors were selected for the CPR to predict whether patients with LDH would demonstrate short-term improvement following conservative therapy with MLT.

Loads in the lumbar spine during traction therapy

The purpose of the present study was to determine the loads acting on the lumbar spine when traction therapy was given in the Fowler's position. The study had two parts: a theoretical analysis which showed that traction produced a flexion moment on the spine as well as axial distraction; and an experimental study which measured the flexion moment induced by the adoption of the Fowler's position. The Fowler's position is clinically essential in that it flexes the spine and takes up the slack of the posterior tissues before the traction force is applied. Hence the axial tension and flexion moment generated by the traction force are more effective in stretching the posterior tissues. The angle of pull on the traction harness influences the friction between the body and the couch. However, this consideration is not necessary if a split traction table is used. The mechanical effects of traction are compared with those produced by postero-anterior mobilisation. The relative magnitude and direction of loads produced, and their variation with segmental level should be considered by therapists when choosing a technique for treating low back pain.

Comparison of Electromyographic Activity in Normal Lumbar Sacrospinalis Muscdature during Static Pelvic -Traction in Two Different Positions*

The purpose of this study was to determine if there is any significant difference in electromyographic activity in normal lumbar sacrospinalis musculature during static pelvic traction between the supine and prone positions. Electromyographic activity was monitored on 17 normal participants. Each participant received static pelvic traction in prone and in supine for 15 minutes. The analysis of variance for a repeated measures design found significantly less lumbar sacrospinalis muscle activity during traction in the prone position than during traction in the supine position (p < 0.05). An analysis of covariance determined that the difference between muscle activity during traction in the prone and supine positions was not significantly affected by differences in sex, age, height, weight, treatment order, time of treatment, electrical noise levels prior to treatment, and electrical noise levels after treatment. Implications for treatment are discussed. J Orthop Sports Phys Ther 1987;8(8):382-390.

Effects of Gravity-Facilitated Traction on lntervertebral Dimensions of the Lumbar Spine*

The purpose of this study was to determine the effects of gravity-facilitated traction (inversion) on intervertebral dimensions of the lumbar spine. Fifteen normal male subjects were fully inverted for a period of 10 minutes. Vertebral separation was measured on lateral roentgenograms both pre- and postinversion by outlining the margins of the intervertebral bodies both anteriorly and posteriorly and the greatest vertical heights of the intervertebral foramina. Fine point engineering calipers were used to facilitate measurements. A student t-test for paired data was used to determine significance of separation between lumbar segments, following 10 minutes of inversion. The alpha level was set at 0.05 for statistical significance. Gravity-facilitated traction produced increased separation at all levels measured. Significant increases in total mean anterior separation, total mean posterior separation, and total mean intervertebral foraminal separation were determined. Mean anterior separation was significant at all levels except L3-L4. Mean posterior separation was significant at all levels except L1-L2 and L5-S1. Mean intervertebral foraminal separation was significant at all levels but L5-S1. If increases in intervertebral dimensions play a role in the relief of low back syndrome, then gravity-facilitated traction may be an effective moda1i;y in the treatment of this condition. J Orthop Sports Phys Ther 1985;6(5):281-288.