Exercise chair and lower extremity exercise system

Abstract

An exercise chair that allows a user to perform a lower extremity exercise in a sitting position includes: a seating portion configured to allow the user to sit on the seating portion; and a first stabilizing portion configured to restrain movement of a first specific portion of the user sitting on the seating portion by contacting the user at a position facing the first specific portion in a front-back direction. The first specific portion is either the fifth or ninth thoracic vertebra of the thoracic spine of the user. The front-back direction is a front-back direction as seen from the user sitting on the seating portion. The exercise chair is configured so as not to restrain movement of any part of the thoracic spine of the user other than the first specific portion.

What is claimed is: 
     
         1 . An exercise chair that allows a user to perform a lower extremity exercise in a sitting position, the exercise chair comprising:
 a seating portion configured to allow the user to sit on the seating portion; and   a first stabilizing portion configured to restrain movement of a first specific portion of the user sitting on the seating portion by contacting the user at a position facing the first specific portion in a front-back direction, wherein:   the first specific portion is either a fifth thoracic vertebra or a ninth thoracic vertebra of a thoracic spine of the user;   the front-back direction is a front-back direction as seen from the user sitting on the seating portion; and   the exercise chair is configured so as not to restrain movement of any part of the thoracic spine of the user other than the first specific portion.   
     
     
         2 . The exercise chair according to  claim 1 , further comprising:
 a support portion that holds the first stabilizing portion so as to allow the first stabilizing portion to be switched between a contact position and a withdrawn position; and   a restricting portion that restricts the first stabilizing portion from switching from the contact position to the withdrawn position, wherein:   the first stabilizing portion is configured to contact the user sitting on the seating portion from a ventral side;   the contact position is the position where the first stabilizing portion faces the first specific portion in the front-back direction and where the first stabilizing portion is able to contact the user sitting on the seating portion; and   the withdrawn position is a position that is different from the contact position and to which the first stabilizing portion is withdrawn to allow the user to sit on the seating portion.   
     
     
         3 . The exercise chair according to  claim 1 , further comprising a second stabilizing portion, wherein:
 the second stabilizing portion is configured to restrain movement of a second specific portion of the user sitting on the seating portion by contacting the user at a position facing the second specific portion in the front-back direction;   the second specific portion is a head of the user or either a first cervical vertebra or a fourth cervical vertebra of a cervical spine of the user; and   the exercise chair is configured so as not to restrain movement of any part of the head and the cervical spine of the user other than the second specific portion.   
     
     
         4 . The exercise chair according to  claim 3 , wherein when the first stabilizing portion contacts the user from a ventral side, the second stabilizing portion contacts the user from a dorsal side. 
     
     
         5 . The exercise chair according to  claim 3 , wherein when the first stabilizing portion contacts the user from a dorsal side, the second stabilizing portion contacts the user from a ventral side. 
     
     
         6 . The exercise chair according to  claim 1 , wherein the first stabilizing portion is configured to protrude toward the user. 
     
     
         7 . The exercise chair according to  claim 1 , wherein the seating portion is configured to rotate in at least one of the following: roll, pitch, and yaw. 
     
     
         8 . A lower extremity exercise system, comprising:
 the exercise chair according to  claim 1 ; and   a lower extremity exercise device.   
     
     
         9 . The lower extremity exercise system according to  claim 8 , wherein the lower extremity exercise device is an exercise device configured to at least apply a load for extension and flexion of hip joints and knee joints of the user. 
     
     
         10 . The lower extremity exercise system according to  claim 9 , wherein the lower extremity exercise device is a pedal exercise device or a stepper exercise device.