Comprehensive Osteopathic Medical Licensing Examination (COMLEX USA) Practice

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Prepare for the COMLEX-USA with quizzes featuring flashcards and multiple-choice questions, each with hints and explanations. Gear up for your osteopathic medicine exam!

Each practice test/flash card set has 50 randomly selected questions from a bank of over 500. You'll get a new set of questions each time!

Practice this question and more.

What type of motion is primarily assessed at the C0-C1 vertebrae?

Flexion
Extension
Rotation
Lateral bending

The correct answer is: Rotation

The C0-C1 vertebrae, also known as the atlanto-occipital joint, primarily facilitate nodding motions, which are associated with extension and flexion. However, the unique anatomic structure and orientation of the C0-C1 articulation primarily allow for significant rotation, particularly when the head is in a neutral position. This joint allows the atlas (C1) to pivot around the dens of the axis (C2), resulting in rotation of the head relative to the spine. Although some flexion and extension occur at this joint, they are not the primary movements when compared to the ample range of rotation that takes place, especially when combined with movements from the C1-C2 joint. Understanding the mechanics of the atlanto-occipital joint reveals why rotation is considered the predominant motion assessed at C0-C1, making it key in clinical assessments of cervical spine function and mobility.