[hip″so-kĭ-ne´sis] a backward swaying or falling in erect posture, seen in parkinson's disease and other neurologic disorders.
hypsokinesis
(hĭp″sō-kĭ-nē′sĭs) [″ + kinesis, movement] A tendency to fall backward when standing or walking; seen in neurodegenerative disorders such as Parkinson's disease.