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Test of Spinal Mobility Called Into Question

Physical therapists (PTs) use a test of spinal mobility called the PA maneuver. PArefers to posterior-anterior. This is the direction of the force applied by the PT at each spinal segment during testing.

The force is generated by the examiner's hand down through the segment with the patient lying face down on a table. The movement is classified as hypomobile (decreased), normal, or hypermobile (increased).

In this study, PTs at the University of Southern California (USC) test the validity and reliability of the PA maneuver. Can joint mobility be tested accurately with a manual maneuver of this type? Can the examiner test every patient with the same amount of force? Can more than one PT get the same result using this test?

Young adults (aged 18 to 45) with low back pain of three months or less were included. Each patient was tested by two different therapists with and without dynamic MRI. Dynamic MRI makes it possible to measure the actual motion of the spinal segment as the examiner performs the test.

Computer analysis of the results showed that the PA maneuver is reliable in finding the least mobile spinal segment. This test was not a good way to find the most mobile segment.

Further testing is needed to identify when the PA maneuver should be used. It's possible that the testing process helps loosen up a stiff segment, thus altering the results. The age of the patient may make a difference. There may be more stiffness perceived in older adults. And stiffness may be misjudged as a loss of segmental motion.

The authors conclude that accurately and reliably assessing joint mobility with manual techniques is difficult at best. In the future, dynamic testing and advanced technology with force sensors may help show us when back pain is caused by spinal instability, stiffness, or some other factor.

References: Rob Landel, PT, DPT, OCS, CSCS, et al. Intertester Reliability and Validity of Motion Assessments During Lumbar Spine Accessory Motion Testing. In Physical Therapy. January 2008. Vol. 88. No. 1. Pp. 43-49.

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