Abstract: A backpack in which length of the shoulder straps automatically adjust as to length when the wearer twists his or her torso. The shoulder straps are connected at their lower end to form one continuous strap. This strap passes below the bottom panel of the backpack, and is contained within a channel. The channel extends along the bottom panel for its entire width from right to left. The channel bends upwardly and forwardly as it exits the bottom panel to follow the side panels of the backpack. A member of low friction characteristics enables the continuous strap to slide freely within the channel. The channel is formed to resist distortion by compression from the load carried within the backpack. The shoulder straps may be elastic, and include an adjustment feature enabling adjustment of their overall length to accommodate different body dimensions.