Comprehensive Osteopathic Medical Licensing Examination (COMLEX USA) Practice

Which sacral torsion is associated with a positive spring test indicating right axis movement?

1. Left on Left

2. Right on Right

3. Right on Left

4. Left on Right

The correct answer is: Right on Right

The correct choice relates to the mechanics of sacral torsion and the spring test. In sacral torsions, the terms "right on right" and "left on left" refer to the positioning of the sacrum in relation to the ilia during the gait cycle. A positive spring test indicates that the sacrum is unable to spring or move freely, which is a characteristic finding in specific sacral torsions. For "right on right" torsion, the sacrum rotates around an axis that runs upward through the right sacral ala. This configuration allows for more mobility in the right side and less in the left side when pressure is applied during the spring test. When the examiner presses down on the sacrum, a positive response (indicating a restriction) suggests that the axis of the motion remains on the right, corroborating that the right side is engaged in the torsional movement. Other types of torsion—like "left on left," "right on left," or "left on right"—would manifest differently during the spring test. They either show no restriction or a different response due to their unique axes of rotation and positioning. Thus, in "right on right" torsion, the spring test results directly confirm this movement