An exercise chair is disclosed that includes a backrest, four legs, and a ball frame, which is configured to nestably receive an inflated ball, such that a top surface of the inflated ball may receive a sitting person. The chair includes a pressure sensor that is positioned beneath a bottom surface of the inflated ball, which is configured to detect pressure exerted by the inflated ball and calculate force measurements resulting from such pressure. The chair also includes an electronic controller/transmitter that is configured to receive the force measurements from the pressure sensor; calculate whether a person sitting on the chair jumped from the chair based on such force measurements during a defined period of time; and communicate a total number of calculated jumps by the person over a defined period of time to the person.

A control assembly for a chair includes a base structure having a first pivot point and a second pivot point spaced from the first pivot point, a seat support structure having a forward portion pivotably coupled to the base structure for rotation about the first pivot point, a back support structure having a forward portion pivotably coupled to the base structure for rotation about the second pivot point, wherein the back support structure is adapted to move between upright and reclined positions, and wherein the seat support structure reclines rearwardly as the back support structure moves from the upright to reclined positions, and a control link having a first end pivotably coupled to a rearward portion of the seat support structure for rotation about a third pivot point, and a second end pivotably coupled to a rearward portion of the back support structure for rotation about a fourth pivot point.

A control assembly for a chair includes a base structure having a first pivot point and a second pivot point spaced from the first pivot point, a seat support structure having a forward portion pivotably coupled to the base structure for rotation about the first pivot point, a back support structure having a forward portion pivotably coupled to the base structure for rotation about the second pivot point, wherein the back support structure is adapted to move between upright and reclined positions, and wherein the seat support structure reclines rearwardly as the back support structure moves from the upright to reclined positions, and a control link having a first end pivotably coupled to a rearward portion of the seat support structure for rotation about a third pivot point, and a second end pivotably coupled to a rearward portion of the back support structure for rotation about a fourth pivot point.

A mobility assistance apparatus includes first and second frames positioned on left and right sides of a user; a hinge arm mechanism coupled to the first and second frames; and a harness or a walking seat coupled to the frames to transfer at least a portion of the user's body weight from the legs and to transfer weight through the user's hip or pelvis to the first and second frame enabling the user to stand and walk or work for an extended period without requiring the user's arms to hold the frame.

Chairs, seating systems, chair sub-assemblies and sub-systems, and associated methods of assembly and use. Aspects relate to chairs and methods of assembling chairs including chair controls of a relatively compact and effective design with desirable synchronous raising and tilting motions. Aspects also relate to tilt lock assemblies for achieving secure and effective tilt securement. Additional aspects relate to forward and rearward adjustment, or extension and retraction, of a seating assembly of the chair.

Chairs, seating systems, chair sub-assemblies and sub-systems, and associated methods of assembly and use. Aspects relate to chairs and methods of assembling chairs including chair controls of a relatively compact and effective design with desirable synchronous raising and tilting motions. Aspects also relate to tilt lock assemblies for achieving secure and effective tilt securement. Additional aspects relate to forward and rearward adjustment, or extension and retraction, of a seating assembly of the chair.

An improved tiltable stool comprises a seat, a body structure, and a base. The base comprises an annular elastic base member having a downwardly convex outer surface and a downwardly concave inner surface. Deformation of the annular elastic base causes a stabilizing force which pushes the tiltable stool towards a normal position when the tiltable stool or chair is tilted out of the normal position. The stabilizing force increases with the weight of a user and provides a consistent dynamic seating experience for users of different weights. An upper section of the annular elastic base is substantially cylindrical and firmly connected to the base structure. The downwardly convex outer surface of a lower section of the annular elastic base member rests on the floor. A contact area between the annular elastic base member and the floor is substantially ring-shaped, and grows outwardly with an increasing weight placed on the seat.

An improved tiltable stool comprises a seat, a body structure, and a base. The base comprises an annular elastic base member having a downwardly convex outer surface and a downwardly concave inner surface. Deformation of the annular elastic base causes a stabilizing force which pushes the tiltable stool towards a normal position when the tiltable stool or chair is tilted out of the normal position. The stabilizing force increases with the weight of a user and provides a consistent dynamic seating experience for users of different weights. An upper section of the annular elastic base is substantially cylindrical and firmly connected to the base structure. The downwardly convex outer surface of a lower section of the annular elastic base member rests on the floor. A contact area between the annular elastic base member and the floor is substantially ring-shaped, and grows outwardly with an increasing weight placed on the seat.

A chair back assembly includes a substantially rigid back frame assembly, a back shell member operably supported by the back frame assembly and including a laterally extending top portion, a laterally extending bottom portion and a pair of longitudinally extending side portion extending between the top portion and the bottom portion and cooperating therewith to define an open space therebetween, wherein the pair of side portions are substantially rigid in a lateral direction, and wherein the back shell member is substantially rigid in a lateral direction and substantially flexibly resilient in a fore-to-aft direction, and a cover having a first surface adapted to support a seated user and a second surface opposite the first surface, wherein the cover is positioned over the back shell member to cover at least a portion of the open space.

A chair back assembly includes a substantially rigid back frame assembly, a back shell member operably supported by the back frame assembly and including a laterally extending top portion, a laterally extending bottom portion and a pair of longitudinally extending side portion extending between the top portion and the bottom portion and cooperating therewith to define an open space therebetween, wherein the pair of side portions are substantially rigid in a lateral direction, and wherein the back shell member is substantially rigid in a lateral direction and substantially flexibly resilient in a fore-to-aft direction, and a cover having a first surface adapted to support a seated user and a second surface opposite the first surface, wherein the cover is positioned over the back shell member to cover at least a portion of the open space.