1. This article and any supplementary material should be cited as follows: Garcia-Mendez Y, Pearlman JL, Cooper RA, Boninger ML. Dynamic stiffness and transmissibility of commercially available wheelchair cushions using laboratory test method. J Rehabil Res Dev. 2012;49(1):XX–XX. http://dx.doi.org/10.1682/JRRD.2011.02.0023 Slideshow Project DOI:10.1682/JRRD.2011.02.0023JSP Dynamic stiffness and transmissibility of commercially available wheelchair cushions using a laboratory test method Yasmin Garcia-Mendez, BS; Jonathan L. Pearlman, PhD; Rory A. Cooper, PhD; Michael L. Boninger, MD

2. This article and any supplementary material should be cited as follows: Garcia-Mendez Y, Pearlman JL, Cooper RA, Boninger ML. Dynamic stiffness and transmissibility of commercially available wheelchair cushions using laboratory test method. J Rehabil Res Dev. 2012;49(1):7–22. http://dx.doi.org/10.1682/JRRD.2011.02.0023 Slideshow Project DOI:10.1682/JRRD.2011.02.0023JSP Study Aim – Evaluate and compare vibration transmissibility of commercially available wheelchair cushions by: Directly measuring transmissibility during wheelchair propulsion. Characterizing cushions with combined material testing and mathematical modeling of human mass. Relevance – Wheelchair users are exposed to vibration. This may contribute to high prevalence of back and neck pain. Characterizing cushion/seating system response to vibrations will help us better understand whether harmful vibrations are entering body.

3. This article and any supplementary material should be cited as follows: Garcia-Mendez Y, Pearlman JL, Cooper RA, Boninger ML. Dynamic stiffness and transmissibility of commercially available wheelchair cushions using laboratory test method. J Rehabil Res Dev. 2012;49(1):7–22. http://dx.doi.org/10.1682/JRRD.2011.02.0023 Slideshow Project DOI:10.1682/JRRD.2011.02.0023JSP Methods Selected 7 commercially available cushions. Measured seated transmissibility for each seat cushion during field tests: – 14 nondisabled subjects propelled wheelchairs over road course. Estimated maximum seat transmissibility and frequency from material testing system and mathematical models with 1 or 2 degrees-of- freedom.

4. This article and any supplementary material should be cited as follows: Garcia-Mendez Y, Pearlman JL, Cooper RA, Boninger ML. Dynamic stiffness and transmissibility of commercially available wheelchair cushions using laboratory test method. J Rehabil Res Dev. 2012;49(1):7–22. http://dx.doi.org/10.1682/JRRD.2011.02.0023 Slideshow Project DOI:10.1682/JRRD.2011.02.0023JSP Results Maximum transmissibility and corresponding frequency values: Wheelchair road course versus 1- and 2-DOF seating system models.

5. This article and any supplementary material should be cited as follows: Garcia-Mendez Y, Pearlman JL, Cooper RA, Boninger ML. Dynamic stiffness and transmissibility of commercially available wheelchair cushions using laboratory test method. J Rehabil Res Dev. 2012;49(1):7–22. http://dx.doi.org/10.1682/JRRD.2011.02.0023 Slideshow Project DOI:10.1682/JRRD.2011.02.0023JSP Results Transmissibility significantly differed for cushions tested. – Air-bladder cushions had lower transmissibility than foam- or gel- based cushions.

6. This article and any supplementary material should be cited as follows: Garcia-Mendez Y, Pearlman JL, Cooper RA, Boninger ML. Dynamic stiffness and transmissibility of commercially available wheelchair cushions using laboratory test method. J Rehabil Res Dev. 2012;49(1):7–22. http://dx.doi.org/10.1682/JRRD.2011.02.0023 Slideshow Project DOI:10.1682/JRRD.2011.02.0023JSP Conclusions Selection of a proper wheelchair cushion is critical to the user’s health and safety. – Most important variables are: Pressure-relieving properties. Weight. Thermal properties. Cleanability. We demonstrated that transmissibility is critical because most cushions amplify vibrations. – Air-based cushions outperformed gel- and foam- based cushions and should be considered to help reduce vibration exposure or prevent spinal pain.