Fat content of lumbar extensor muscles and low back disability: a radiographic and clinical comparison.

The fat content of the lumbar back extensor muscles was assessed from computed tomograms and correlated to self-reported disability in 39 consecutive chronic low back pain patients. The assessment for the quality of fat was done separately for the three lowest lumbar intervertebral levels. The Oswestry index was used to evaluate the low back disability. Analysis showed positive relationship between the fat content of the lumbar paraspinal muscles at lumbosacral level and self-reported disability in men. The relationship was weaker in women, and at higher lumbar levels it was not found in either sex.