An adjustment mechanism configured for adjusting a backrest of a chair, including a clamp element configured to be fixedly attached to a static frame, which extends along a longitudinal axis; a guided frame selectively moveably coupled to the clamp element and configured to be fixedly attached to the backrest, and wherein displacement of the guided frame relative to the clamp element is configured to urge corresponding displacement of the backrest either axially along a first axis extending generally transversely with respect to the longitudinal axis or angularly with respect to the longitudinal axis.

A portable lumbar support and ergonomic chair having a lumbar support. The lumbar support has a seat hingedly coupled to a seat back having a teardrop-shaped lumbar support seat back cushion. A rigid back support portion may be rotated forward about hinges to collapse substantially parallel to the seat frame and backward to open to a variety of angles with respect to the seat frame. The seat back freely pivots around an upper lateral axis, and the rigid back support portion is linearly adjustable to space the seat back toward and away from the hinges to enable raising or lowering the upper lateral axis and thus the seat back with respect to the lower lateral axis. This provides multiple ways of changing which part of the teardrop-shaped lumbar support curve hits your lumbar curve for proper support. Variable lumbar lordotic support is thus provided.

An orthopedic device for improving posture while sitting, having a foundation member including a front portion for upper legs and a bowl portion for lower pelvic area. The bowl portion has a central portion and an upwardly inclined lateral portion. The lateral portion and the front portion collectively surround the central portion. A channel attachment is connected with one or more pelvic crest portions. The channel attachment portion connects over a concave recessed portion. The central portion has plural regions of varying flexibility and the lateral portion has plural regions of varying flexibility.

A chair waist backrest height adjusting device includes a chair backrest bracket above the backrest, a worm rotated by turning the adjusting rod to slightly lower position, a first gear that is engaged with it and a second gear that is coaxially rotated with the first gear, and the chair backrest bracket under the backrest is provided with a waist backrest that can be slid up and down. The back of the waist backrest is provided with a tooth-row that is engaged with the second gear, so that the seated person on the chair can stretch out one or two hands to the adjustment rod for the forward or reverse turning operation, and the waist backrest can easily drive the waist backrest up and down, further the waist backrest is more easily adjusted, and there will be no displacement in the adjusted waist backrest.

An adjustable stool having a support connected to a base at one end and seat at the opposite end. A foot rest is adjustably connected to the support. Adjustably connected to the seat is a back support. A lumbar support is adjustably connected to the back support. The back support has a horizontal portion and a vertical portion.

A therapeutic chair with an adjustable backrest and cushioned fulcrum pad allows users to extend their thoracic spine over the fulcrum of the adjustable chair back. The device allows the individual to sit on the chair and adjust the height of the backrest so the fulcrum is matched to the patient's need for movement.

A chair assembly (1) of a chair or an armchair comprises a seat body (2), a backrest body (6), a locking and adjustment device (4), and a backrest support (10). The backrest support (10) is engaged with an articulated parallelogram that allows the position of the backrest body (6) to be changed while keeping it parallel to itself. The backrest support (10) further comprises spring return means.

An ergonomically improved chair in which the user's thoracic region is supported by a narrow and generally flat or moderately convex thoracic cushion in the midrest region of the chairback. The design omits or greatly minimizes support for the user's scapulae and other areas of the back outside the thoracic region, excepting lumbar and cervical support features in some embodiments. The design differs from the prior art at least in that the thoracic cushion is narrow and configured not to complement that user's spinal curvature. By appropriate selection and design, a chair incorporating the invention may comprise a fabric covering portions of the chairback without significantly affecting functionality. Other embodiments include a chairback comprising regions having differing levels of firmness and/or differing cushion height at appropriate regions to promote concentrated support of the user's thoracic region.

The self-adjustable backrest device supplements a seat surface such that said seat surface is a previously existing one and what is covered by the object of this invention adds a backrest or improves the existing one, for which purpose it comprises a mobile plate on which the user rests, wherein said plate swivels on a horizontal shaft that passes through a first set of hubs connected to the plate, that shaft being associated with a second set of hubs connected to a support that may be the backrest itself of the chair or easy chair on which the self-adjustable backrest is going to be used, in which case it will be referred to as pre-existing backrest, or it may be a fixed backrest which forms part of the device, in which case it will be referred to as backrest of the device. The device may include fixing elements to prevent its movement, such as legs, pegs, or a flap.

Among other things, a seat includes a back-supporting surface; and a seating surface movable along a path toward and away from the back-supporting surface. At least part of the back-supporting surface is movable to enable a lower portion of the back-supporting surface to move substantially along the path.