| 摘要 |
An apparatus includes a substantially vertical elongated mast and a substantially horizontal elongated boom which is supported by the mast proximate an upper end thereof. The boom can pivot independently about a substantially vertical first axis and a substantially horizontal second axis. The boom has a first end proximate the mast and a distal opposite second end. A gripping element, for gripping by a user of the apparatus while the user is supported thereby, depends from the boom proximate the second end thereof. An elastic biasing member operatively attached to the mast and the boom provides a biasing force to bias the boom toward a rest position and against downward movement of the second end of the mast. The biasing member allows a temporary downward movement of the second end of the boom due to sudden application of weight of a user's body when the user grasps the gripping element.
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