A seat assembly includes a seat frame, a back frame 320 defining a back plane pivotally connected to the seat frame at a pivot joint, a back support 310 slideably secured to the back frame, and a back support adjusting mechanism. The back support adjusting mechanism includes a first linking member 355 coupling the back support to the seat frame and pivotable about the pivot axis, and a first slide member 351 slideably supported by the back frame and operatively connected to the first linking member. A second slide member 354a is affixed to the back support and slideably supported by the back frame. A second linking member 352 operatively connects the first and second slide members. Pivoting movement of the back frame from the upright position to the reclined position slides the first slide member away from the pivot axis, causing the second linking member to slide the back support toward the pivot axis.

A positioning frame for supporting a patient to facilitate different surgical approaches to the spine includes a main support beam, first and second support structures, a torso-lift support, and a pelvic-tilt support. The main support beam has a first end, a second end, and a length extending between the first and second ends. The main support beam defines an axis of rotation relative to at least a first support structure and a second support structure, and the axis of rotation substantially corresponds to a cranial-caudal axis of the patient when the patient is supported on the positioning frame. The first and second support structures support the main support beam, and space the main support beam from the ground. The torso-lift support is attached to the main support beam, and is configured to pivot a chest support plate between at least a first position and a second position to move the torso of the patient between an unlifted position and a lifted position. The pelvic-tilt support is attached to the main support beam, and is configured to support the thighs and the lower legs of the patient. Portions of the pelvic-tilt support are pivotal with respect to one another to facilitate adjustment of the hips of the patient.

A sliding thorax assembly subframe is mounted to a thorax assembly main frame section of an articulating bed and is adapted to descend as the torso section of the bed is raised to an inclined position. The mechanism, which is optionally combined with a slideback mechanism to extend the pelvic area of the bed in a longitudinal direction, reduces compressive and shear forces on the patient during bed articulation.

A cover system includes a base sheet, which is adapted to cover an underlying mattress, and a top sheet configured to wick away moisture and to cooperate with the base sheet to reduce shear on a patient supported on the cover system.

A tiltable wheelchair comprises a tilt seat guide assembly supported in relation to a base frame and a first roller supported in relation to the tilt seat guide assembly for supporting a seat frame for movement in relation to the base frame. The first roller is movable along the tilt seat guide assembly in fore and aft directions to enable tilt of the seat frame in relation to the base frame. A link arm may be connected between the base frame and seat frame to urge the seat frame upward and rearward to tilt the seat frame as the first roller moves in a forward direction. A second roller may be provided to cooperate with a guide rail, which is supported in relation to the tilt seat guide assembly, so as to track the movement of the first roller and prevent lateral translation of the seat frame in relation to the base frame. A locking device may be provided for holding the seat frame in a desired position.

A positioning frame and method for use thereof for supporting a patient to facilitate different surgical approaches to the spine is provided. The positioning frame includes a main support beam, first and second support structures, a torso-lift support, and a pelvic-tilt support. The main support beam has a first end, a second end, and a length extending between the first and second ends. The main support beam defines and is rotatable an axis of rotation relative to at least the first and second support structures to adjust the rotatable position of the patient support thereby. The torso-lift support is attached to the main support beam, and is configured to pivot to move the torso of the patient between an unlifted position and a lifted position. The pelvic-tilt support is also attached to the main support beam, and is configured to support and move the thighs and the lower legs of the patient to facilitate adjustment of the hips of the patient.