The Immediate Effect of Posteroanterior Mobilization on Reducing Back Pain and the Stiffness of the Lumbar Spine
Gary L. Shum, PhD
Archives of Physical Medicine and Rehabilitation
Volume 94, Issue 4 , Pages 673-679, April 2013

Abstract
Objective
To study the immediate effect of posteroanterior mobilization on back pain and the associated biomechanical changes in the lumbar spine.

Design
An experimental between-group study.

Setting
A biomechanics laboratory.

Participants
Subjects with low back pain (n=19) and healthy subjects (n=20).

Interventions
Grade III posteroanterior mobilization (3 cycles of 60s) was applied at the L4 level in people with or without back pain on 1 occasion.

Main Outcome Measures
Pain intensity, active lumbar range of motion, the magnitude of the posteroanterior mobilization loads, bending stiffness of the lumbar spine, and the lordotic curvature of the lumbar spine before and after 3 cycles of posteroanterior mobilization.

Results
The magnitude of pain of the patients was found to decrease significantly after posteroanterior mobilization treatment. There was also a significant decrease in the bending stiffness of the lumbar spine of the patients, which was derived from the posteroanterior load and the associated change in spine curvature. The stiffness was restored to a level that was similar to that of the asymptomatic subjects. A strong correlation was found between the magnitude of pain and the bending stiffness of the spine before (r=.89) and after posteroanterior mobilization (r=.98).

Conclusions
Posteroanterior mobilization was found to bring about immediate desirable effects in reducing spinal stiffness and the magnitude of back pain. The restoration of the mechanical properties of the spine may be a possible mechanism that explains the improvement in pain after manual therapy.