Why Do Stabilization Exercises Work for Some Back Patients?
In 2005, a group of physical therapists (PTs) published a study outlining the first clinical prediction rule for patients with low back pain (LBP). Using this tool, PTs are able to predict which LBP patients might benefit from a program of lumbar stabilization exercises.

In this study, another group of PTs used digital fluoroscopic video (DFV) to look at movement patterns in back pain patients. These patients were judged by the CPR to be good candidates for stabilization exercises.

Lumbar motion was captured by DFV and analyzed using computer software programs. A full cycle of flexion and extension in the standing position was recorded. Movement patterns were compared between a group of 20 LBP patients and another group of 20 adults without LBP.

The program allowed the researchers to look for differences in speed, sequence, and timing of muscle action and motion. This is called a kinematic analysis. The analysis showed a disordered movement pattern present during the first 15 per cent of lumbar flexion.

The normal group had an even rate and flow of motion across all lumbar segments. The LBP group only had a normal response at the L5-S1 segment. In fact, motion at the upper segments was either absent or went in the opposite direction.

Just the opposite reaction occurred during lumbar extension. There was a delay in the rate and angle of motion at all segments except one. This difference was seen during the last phase of motion as the patients returned to the upright position after bending forward.

The authors describe this pattern of decreased motion as segmental hypomobility. This finding was a surprise because it has been assumed that lumbar instability in LBP patients was a result of hypermobility (too much motion) at one or more lumbar segments, not a decrease in motion.

The results of this study are preliminary but may help therapists understand why some patients would respond better than others to lumbar stabilization exercises.
Deydre S. Teyhen, et al. Arthrokinematics in a Subgroup of Patients Likely to Benefit From a Lumbar Stabilization Exercise Program. In Physical Therapy. March 2007. Vol. 87. No. 3. Pp. 313-325.