A modern<unk>  on the street A<unk>  is a chair with wheels, used when walking is difficult or impossible due to illness, injury, problems related to old age, or disability. These can include spinal cord injuries (paraplegia, hemiplegia, and quadriplegia), cerebral palsy, brain injury, osteogenesis imperfecta, motor neurone disease, multiple sclerosis, muscular dystrophy, spina bifida, and more.<unk> s come in a wide variety of formats to meet the specific needs of their users. They may include specialized seating adaptions, individualized controls, and may be specific to particular activities, as seen with sports<unk> s and beach<unk> s. The most widely recognized distinction is between motorized<unk> s, where propulsion is provided by batteries and electric motors, and manual<unk> s, where the propulsive force is provided either by the<unk>  user/occupant pushing the<unk>  by hand ("self-propelled"), by an attendant pushing from the rear using the handle(s), or by an attendant pushing from the side use a handle attachment.
Wheelchair
Air purifier
Gait trainer
Baby walker
Pneumonic device
Needleless connector
Toftness device
Horopter