Chair, and lower-limb exercise system

Abstract

A chair includes: two coxal bone support balloons that support two coxal bones respectively; and a sacral bone support balloon that supports one of a sacral bone and a coccygeal bone. The two coxal bone support balloons are configured to be able to rock relative to the sacral bone support balloon. In this configuration, the movability of a sacroiliac joint between the two coxal bones and the sacral bone is improved, and therefore, the mechanical stress on a lumbar region joint, on which a load increases in compensation for an insufficient movability of the sacroiliac joint, is curbed, so that a low back pain is relieved.

Dependencies are inferred from the claim text.