Wearable strain sensors have applications in physical therapy, training technique, rehabilitation, respiration monitoring and diagnostics [1]. Strain sensors placed on the body have the potential to provide digital measurements of joint angles and bending movements. One such measurement is the Modified Schober’s test (MST). The MST is the standard clinical test for measuring the flexion of the spine and is used as part of the diagnosis of many types of arthritis and diseases affecting the spine including ankylosing spondylitis (AS). The test involves marking 5 cm below and 10 cm above the iliac crest and using a tape measure to determine the increase in distance when a patient bends forward. Typically, an increase of 5 cm or more is considered a healthy spine [2]. This test method relies on the accuracy of the clinician, which leads to a high percentage of human error [3]. Using a strain sensor for this application would reduce inter-observer error and provide more consistent measurements over time. The proposed sensor was manufactured by integrating CNTs onto spandex threads to create a piezoresistive sensor. A testing method was created to determine sensor’s ability to differentiate between incremental increases in strain. Various sensor lengths and core sizes were chosen, and after preliminary testing, a 16.5 cm 8 core sensor was chosen to have the best separation between consecutive percent strains. The results of this work will be implemented in a real-time wearable device which can more accurately diagnose afflictions of the spine. REFERENCES: [1] S. Coyle, Y. Wu, K. T. Lau, D. De Rossi, G. Wallace, D. Diamond, “Smart Nanotextiles: A Review of Materials and Applications”, MRS Bulletin, Vol. 32, issue 5, pp. 434–442, 2007. [2] K.M. Houghton, “Review for the generalist: evaluation of low back pain in children and adolescents”, Pediatr. Rheumatol. Online J., vol. 8, pp 28-36, 2010. [3] E. Aartun, A. Degerfalk, L. Kentsdotter, L. Hestbaek, “Screening of the spine in adolescents: inter- and intra-rater reliability and measurement error of commonly used clinical tests”, BMC Musculoskelet. Disord., vol. 15, no. 1, pp. 37, 2014.