Biomechanic evaluation of the rola stretcher as a passive distraction device

Introduction: Many devices have been marketed claiming to increase the mobi lity of the articulations of the spine with active or passive distraction. In this study, the Rola Stretcher (Unique Relief, Inc, Davenport, Iowa) and an earlier version, the True Back II (True Back, Inc, Clearwater, Fla), we re evaluated to see if they have a measurable biomechanic effect on the spi ne. Methods: Two studies were conducted, each with 6 male participants and 6 fe male participants, using a sta- diometer to accurately measure a person's s itting height. The increase in sitting height after using the True Back II or Rola Stretcher for 10 minutes was compared with that after lying supine for 10 minutes. A third intervention, a firm foam block cut to the same siz e and shape as the True Back II, was also used in this study. Results: The Rola Stretcher had a significantly greater lengthening effect on the spine compared with supine rest (P <.0050). The True Back II had a s imilar but lesser effect (P <.0509). Women demonstrated a greater height ga in than men. Conclusion: The True Back II and the Rola Stretcher in particular appear to lengthen the spine after a single use of 10 minutes. The observed discrepa ncy between the effects in men and women may be an experimental artifact oc curring as a result of less effective resetting of the posturing mechanisms in men compared with women. A trend showed the Rola Stretcher to be more e ffective than the foam block.