Hyperkinesia
A tic can be defined as a repeated, individually recognizable, intermittent movement or movement fragments that are almost always briefly suppressible and are usually associated with awareness of an urge to perform the movement. These abnormal movements occur with intervening periods of normal movement. These movements are predictable, often triggered by stress, excitement, suggestion, or brief voluntary suppressibility. Many children say that the onset of tics can stem from the strong urge to move. Tics can be either muscular (alter normal motor function) or vocal (alter normal speech) in nature and most commonly involve the face, mouth, eyes, head, neck or shoulder muscles. Tics can also be classified as simple motor tics (a single brief stereotyped movement or movement fragment), complex motor tics (a more complex or sequential movement involving multiple muscle
groups), or phonic tics (including simple, brief phonations or vocalizations).
Sidecar
A sidecar motorcycle is a three-wheeled vehicle with the side wheel not directly aligned with the rear motorcycle wheel, and is usually powered by the rear wheel only. This is different from a motor tricycle (trike), where both rear wheels are powered and share a common axle. However, either P.V. Mokharov of the Soviet Union or H.P. Baughn of Great Britain seem to have been the first to employ a driven sidecar wheel in 1929. Baughn two-wheel-drive outfits were so successful in trials events in the early 1930s that there were attempts to have the ACU ban them from competition. A great many companies experimented with two-wheel drive in sporting events and indeed many companies employed them in military vehicles prior to the commencement of World War II. Currently, the Russian manufacturer Ural produces several models with two-wheel drive that can be engaged as desired.