Many muscles move the spine and help keep it stable. Researchers know that patients who have low back pain (LBP) often have problems in the muscles that work the spine. But do the muscle problems cause LBP, or does the pain and inactivity of LBP cause problems in the muscles? The answer may be different in different patients.
In this small study, researchers tested the effects of back strengthening exercises on patients with LBP. All patients had the size and density of the muscles around the spine measured. They also answered questions about pain and about what activities they avoided because of their pain. Then one group of patients was given specific exercises. In two to three one-hour sessions a week, these patients worked to strengthen thigh, back, and abdominal muscles, including some of the deep muscles that stabilize the spine. The control group did no special exercises.
After 15 weeks, the muscle size and density tests were repeated. Muscle differences were seen at a specific level of the lower spine (between the fourth and fifth lumbar segment, L4 and L5). The exercise group showed an increase in muscle, while the control group actually lost muscle in that area. The exercise group also scored better on pain and lifestyle questions than the control group. However, the researchers were surprised to find that the exercise group and the control group still scored about the same on strength tests.
The authors note that this study was limited by the small number of patients who took part. They also question whether the exercises were actually related to the decrease in pain and the increase in function in the exercise group. More research is needed to figure out exactly what kinds of rehabilitation help patients with LBP.