Measuring Abdominal Muscle Control in Low Back Pain

Muscles work differently in people with low back pain (LBP). This study uses ultrasound to show what happens to the abdominal muscles in LBP patients. The researchers also confirmed that ultrasound is a good tool for checking the abdominal muscles.

Two groups of 10 people were studied. The first group had recurring episodes of LBP. The second group had no back pain at all. Ultrasound was used to measure changes in thickness of three abdominal muscles. Electromyography (EMG) was also used to record muscle activity.

Measurements were taken during leg movements. The researchers report differences in thickness of only one abdominal muscle between the two groups. The transverse abdominal muscle (the deep abdominal muscle) was much thicker in the group without pain, and it was active with both leg flexion and extension. This wasn't true for most of the LBP patients.

Results of this study show that patients with LBP use trunk muscles differently than people without back pain. Activity of the transverse abdominals was lower for patients with LBP in one direction of movement. This may mean that the transverse abdominal muscle doesn't contract when it should in people with LBP.

Until now scientists haven't had a good way to measure activity of muscles deep inside the body. The authors of this study conclude that ultrasound can measure changes in muscle thickness. Ultrasound directly measures muscle contraction. Finding muscles that aren't working properly in patients with LBP will help develop better treatment.



References: Paulo H. Ferreira, MSc, et al. Changes in Recruitment of the Abdominal Muscles in People with Low Back Pain. In Spine. November 15, 2004. Vol. 29. No. 22. Pp. 2560-2566.