Ultrasonographic determination of lumbar spine angulation

Abdominal ultrasonograms of recumbent, supine adult subjects were used to measure the angle formed between the horizontal plane and a plane along the anterior border of upper lumbar vertebral bodies. The angle, referred to as phi, for male and female subjects averaged 8.8 degrees. When this angle was compared in subjects with the hips flexed and extended, there was no significant difference. There was a significant difference between subjects in a recumbent position and a standing position. The amount of angulation was compared to the age of the individual and found to have a low correlation coefficient. The angle phi appears to be a good indicator of the amount of lordosis, it related well to previous methods of measuring lordosis, and it is a benign procedure in a genetically sensitive region.