circus movement, 1. an unusual and involuntary rolling or somersaulting caused by injured neural structures that control body posture, such as the cerebral pedicles or the vestibular apparatus. 2. an unusual circular gait caused by injury to the brain or spinal cord. 3. a mechanism associated with the excitatory wave of the atrium of the heart and atrial flutter or fibrillation. The wave travels a circular path characterized by a gap between the refractory and the excitatory tissue, usually resulting in conduction of only a fraction of the impulses to the ventricle.
