Sentence:  Wheelchairs are used by people for whom walking is difficult or impossible due to illness (physiological or physical), injury, or disability. People with both sitting and walking disability often need to use a <WSD>wheelbench</WSD>. 
Meaning of the word marked with <WSD> tags:  A manually propelled, wheeled mobility device in which the user lies down. The user pushes the wheels with the hands in a similar way to propelling a wheelchair or, alternatively, a second person pulls or pushes it by the handles.