An articulating bed comprising: a support frame with a head end, a foot end and having side frame members; a carriage having a seat support and carried by the side frame members, said carriage mounted with wheels engaging the side frame members to translate from a first position through a range progressing toward the head end to a fully translated position; an upper body support rotatably connected to the carriage and carrying a mattress support; at least one telescoping rotation strut attached at a first end and rotating through an axle pivotally attached to the side frame members, said at least one telescoping rotation strut engaging at a second end the upper body support whereby translation of the carriage from the first position compressively urges the upper body support against the at least one telescoping rotation strut thereby rotating the at least one telescoping rotation strut and upper body support during a first range of motion of the carriage; at least one fixed length rotation arm carried at a first end by a rotating tube and pivotally attached to the upper body support at a second end, said rotating tube mounted on wheels constrained in a track, said rotating tube translating laterally in the track during the first range of motion and contacting a track end proximate the head end of the frame at a termination of the first range of motion, said at least one telescoping strut approaching a vertical orientation at a termination of the first range of motion transferring reaction forces to translation of the carriage to the at least one fixed length rotation arm, whereupon the at least one telescoping rotation strut extends through a second range of motion of the carriage to fully articulate the upper body support section with the carriage in the fully translated position. a support frame with a head end, a foot end and having side frame members; a carriage having a seat support and carried by the side frame members, said carriage mounted with wheels engaging the side frame members to translate from a first position through a range progressing toward the head end to a fully translated position; an upper body support rotatably connected to the carriage and carrying a mattress support; at least one telescoping rotation strut attached at a first end and rotating through an axle pivotally attached to the side frame members, said at least one telescoping rotation strut engaging at a second end the upper body support whereby translation of the carriage from the first position compressively urges the upper body support against the at least one telescoping rotation strut thereby rotating the at least one telescoping rotation strut and upper body support during a first range of motion of the carriage; at least one fixed length rotation arm carried at a first end by a rotating tube and pivotally attached to the upper body support at a second end, said rotating tube mounted on wheels constrained in a track, said rotating tube translating laterally in the track during the first range of motion and contacting a track end proximate the head end of the frame at a termination of the first range of motion, said at least one telescoping strut approaching a vertical orientation at a termination of the first range of motion transferring reaction forces to translation of the carriage to the at least one fixed length rotation arm, whereupon the at least one telescoping rotation strut extends through a second range of motion of the carriage to fully articulate the upper body support section with the carriage in the fully translated position.