A medical chair has a cranium position regulating device and a pelvis-and-knee position regulating device for respectively regulating the positions of the cranium and pelvis of a subject who sits on a seat. The cranium position regulating device and the pelvis-and-knee position regulating device have structures in which they butt against both right and left sides of the cranium and the pelvis, respectively, to cause both planes centered in a right-and-left direction of the cranium and the pelvis to be in a same central plane which extends in the direction of gravity. An ideal condition of the body of the subject in which vertical and horizontal balances are achieved against the force of gravity can be achieved to ensure physiological curvature of vertebrae and the condition can be maintained.
1. A medical chair which is mainly useful for maintaining a relaxed condition of muscular tension of a human body in a condition where physiological curvature of individual vertebrae is realized and human body extends along a direction of gravity, and characterized in that
said chair comprises cranium position regulating means and pelvis-and-knee position regulating means for respectively regulating a position of a cranium and a position of a pelvis of a subject who sits on a seat, and said cranium position regulating means and said pelvis-and-knee position regulating means butt against both right and left sides of the cranium and the pelvis, respectively to cause both planes centered in a right-and-left direction of the cranium and the pelvis to be in a same central plane which extends in the direction of gravity, said pelvis-and-knee position regulating means further including knee butting means for butting against the outside of the knees of the subject in a seated condition to cause an angle formed by the knees to be bilaterally symmetrical about the central plane, thereby fixing positions of the knees.
2. A medical chair according to claim 1 , wherein said chair further comprises height adjusting means for adjusting a vertical distance between a foot sole placing plate and a seat face, to cause soles of feet of the subject in a seated condition to be closely in contact with a horizontal plane.
3. A medical chair according to claim 1 or 2 , wherein said chair further comprises lumbar vertebra pressing means for, from a rear side, pressing lumbar vertebra of the subject in a seated condition at a predetermined height from said seat.
4. A medical chair according to claim 1 or 2 , wherein said chair further comprises armpit position regulating means for butting against both armpits of the subject in a seated condition to cause a plane centered in the right-and-left direction of the armpits to be in the central plane thereby fixing positions of the armpits.
5. A medical chair according to claim 1 or 2 , wherein said chair further comprises cranium fore-and-aft position regulating means for butting against a back of a head of the subject in a seated condition, thereby regulating a position of the cranium in a fore-and aft direction.
6. A medical chair according to claim 1 or 2 , wherein said chair further comprises seat face angle adjusting means for changing an angle of a seat face of said seat with respect to a horizontal plane.
7. A medical chair according to claim 1 or 2 , wherein a hole or a recessed portion is formed in a substantially central portion of a seat face of said seat.
8. A medical chair according to claim 1 or 2 , further comprising armpit position regulating means and wherein each of said cranium position regulating means, said pelvis-and-knee position regulating means, and said armpit position regulating means includes: a pair of regulating members which are respectively positioned on right or left sides of the subject in a seated condition, and which butt against a corresponding region; and an adjusting mechanism which moves said pair of regulating members in a horizontal direction, and each of said adjusting mechanisms moves said pair of regulating members by equal distances in a bilaterally symmetric manner about a center line of said chair.
9. A medical chair according to claim 1 or 2 , further comprising armpit position regulating means having armpit position regulating members and lumbar vertebra pressing means having lumbar vertebra pressing members and wherein, in said cranium position regulating means, said armpit position regulating means, and said lumbar vertebra pressing means, said armpit position regulating members and said lumbar vertebra pressing members butting against the subject are disposed in a vertically movable manner by means of respective vertical movement mechanisms in accordance with a body shape of the subject.
10. A medical chair according to claim 1 or 2 , further comprising armpit position regulating means, lumbar vertebra pressing means, and seat face angle adjusting means and wherein said chair further comprises storing means for storing positions of pairs of regulating members in said cranium position regulating means, said pelvis-and-knee position regulating means, and said armpit position regulating means, a position of a pressing member in said lumbar vertebra pressing means, or an angle of a seat face in said seat face angle adjusting means for each subject, and, when energized, and the positions of said pairs of regulating members and said pressing member, or the angle of said seat face are moved to positions or an angle corresponding to the subject, by means of actuators, based on the stored positions in said storing means.