Treadmill Walking in Claudication Shane Lentza, Sara A. Myersa,b, Iraklis Pipinosb,c, Jason Johanningb,c aUniversity of Nebraska at Omaha, Omaha, Nebraska bOmaha Veterans Affairs Medical Center, Omaha, Nebraska cUniversity of Nebraska Medical Center, Omaha, Nebraska INTRODUCTION RESULTS Claudication is lower leg pain caused by walking that is relieved with rest1,2. The pain has two potential causes: peripheral artery disease (PAD; Figure 1)3 and lumbar spinal stenosis (LSS; Figure 2)4. PAD is a disease caused by plaque buildup in arteries of the lower extremities3. LSS is a condition in which narrowing of the spinal canal occurs in the lower back4. Neurogenic claudication is the key characteristic most identified with LSS5. Vascular claudication is the defining characteristic of PAD. There is no non-invasive way to determine which condition is causing the claudication. Purpose: The purpose of this study is to utilize biomechanics to distinguish between individuals with claudication that arises from neurogenic versus vasculogenic causes. LSS PAD Figure 3. The above graph compares LSS and PAD ground reaction forces in a step. On average, LSS exhibits lower ground reaction forces than PAD6. Figure 4. Comparing stride time between LSS and PAD groups. PAD patients exhibit a lower stride time7. Figure 5. Comparing claudication distances between LSS and PAD groups. PAD patients display shorter claudication distances8. DISCUSSION LSS patients exhibited overall lower ground reaction forces when compared to patients with PAD (Figure 3). PAD patients displayed a lower stride time than LSS patients (Figure 4). It appears that the onset of claudication pain is quicker in PAD subjects than LSS subjects (Figure 5). PAD patients tend to shorten their gait stride as pain becomes more apparent, causing a decreased stride time compared to LSS patients. Further research is needed to help differentiate between the two causes of claudication. Figure 1. Atherosclerotic blockages in the arteries limiting oxygenated blood to the lower extremity. Figure 2. LSS causes narrowing of the spinal canal, leading to impinged nerves. METHODS n Age Mass LSS 4 73.0 + 6.5 yrs 103.8 + 12.3 kg Subjects LSS and PAD subjects were compared during a walking test on a treadmill. REFERENCES 1. Watanabe T, et al. ScientificWorldJournal. 2014. 2. Watanabe T, et al. Conf Proc IEEE Eng Med Biol Soc. 4696-9, 2012. 3. Norgren L, et al. J Vasc Surg. 45, S:S5-67, 2007. 4. Kobayashi S, World J Orthop, 5(2), 134-45, 2014. 5. Haig A, et al. Spine J, 13(12), 1826-34 ,2013. 6. Scott-Pandorf, M, et al. Journal of vascular surgery, 46(3), 491-499, 2007. 7. Schieber, Molly N., “Gait Alterations in Peripheral Arterial Disease are not Worsened by the Presence of Diabetes.“ 8. Myers, Sara A., et al.  Journal of vascular surgery, 47.3, 550-555, 2008. Noraxon FDM-T SCIFIT Treadmill Pressure sensored Continually measures force distribution during walking Gardner Test Walk at a constant speed of 2.0 mph. Treadmill inclines 2% every two minutes. Test ends when subject can no longer walk due to pain. Analysis Data from LSS and PAD6,7,8 groups were compared. Dependent variables included ground reaction force, stride time, initial claudication distance (ICD) and absolute claudication distance (ACD). ACKNOWLEDGMENTS Funding provided by the University of Nebraska Fund for Undergraduate Scholarly Experience (FUSE), NIH P20 GM109090, R01AG034995 and R01HD090333) and VA RR&D (1I01RX000604)