Lumbosacral angle

Is the lumbosacral junction a smooth transitional curve Does the lumbosacral angle appear normal ... 

The iliopsoas muscle also plays an important role in the synergistic activities of the muscles of the low back in maintaining a normal lumbosacral angle and proper postural balance. 

The lumbosacral angle is the angle formed in the upright position, from a side view, by extending the line of inclination ofthe sacrum as it meets a line parallel to the ground. This angle is normally... 

An increased lumbosacral angle changes the articular relationships, because the inferior lumbar facets slide caudally on their matched superior sacral facets. 

The effect of an increased lumbosacral angle as well as possible causes has been discussed previously. Ofgreat importance in the treatment of this condition is the prescription of proper exercises. These must include abdominal strengthening, paravertebral muscle stretching, lumbar flattening, and psoas and hamstring stretching. 

Review of some everyday activities demonstrate their effect on the pelvic structures. In the standing position, body weight is transmitted through the fifth lumbar vertebra to the sacrum, where the force vector splits in two. One force vector drives the sacrum into its articulation, and the other rotates the sacrum anteriorly. The greater the lumbosacral angle, the greater is the anterior vector force, which in turn increases the lumbosacral strain (Fig. 57-2). 

FIG. 57-2 An increase in the lumbosacral angle creates a greater anterior vector force, which increases the lumbosacral strain. 

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