Proven quality! an independent laboratory compared the high quality mckenzie lumbar rolls with competitive products and found "...the optp lumbar roll is more supportive, will not lose its supportive qualities as quickly, and will offer more consistent support longer than the other rolls sampled." the lumbar roll challenge - an independent laboratory confirmed the superiority of the original mckenzie lumbar roll in a blind random analysis with Test rolls from our largest competitors. While the Manufacturer Contact Information Not Applicable