Jerky movement is a term used to describe an abrupt, sudden, and uncontrolled movement. It is also known as a TWITCH, which is a 6 letter word that can be used to describe this type of movement. Jerky movement can be caused by a variety of medical conditions, such as Parkinson's disease, multiple sclerosis, or even stress. It can also be a sign of a neurological disorder. In any case, jerky movement can be disruptive and uncomfortable for the person experiencing it.