No chair has flown higher than the Nada-Chair's premier product, the Back-Up ($70). It has traveled with the astronauts to space to help ease micro-G induced back pain. But its more down-to-earth application is keeping computer users sitting comfortably upright. These "terminal" sitters need the extra cushion that is provided by our Back-Up. Its knee cushions and back pad are twice as thick as the next-in-line S'portBacker. It also comes with accessory CushShins to disperse the leaning weight over three times as much area of the shin. For this reason, this is the first choice for those with bigger body builds. Accessory Stretch Straps can be purchased separately to lengthen the leg loops to engage the feet. With these, you can lean against your feet to sit on the ground, read in bed or do stretching exercises without compromising your low back.