The aim of this study is to develop a detailed algorithm which will automatically detect falls and near falls, in the elderly as a general population prone to falls. The algorithm will be used as well in patients with Parkinson's Disease representing neurodegenerative diseases. All participants will arrive at the investigators' gait laboratory for an inhanced assessment, including neurological examination, various questionnaires. A sub-group of the subjects, will receive a monitoring device, to be worn at home for three days.