RELIABILITY OF A COMPUTER SOFTWARE ANGLE TOOL FOR MEASURING SPINE AND PELVIC FLEXIBILITY DURING THE SIT-AND-REACH TEST

Mier, CM and Shapiro, BS. Reliability of a computer software angle tool for measuring spine and pelvic flexibility during the sit-and-reach test. J Strength Cond Res 27(2): 501-506, 2013. The purpose of this study was to determine the reliability of a computer software angle tool that measures thoracic (T), lumbar (L), and pelvic (P) angles as a means of evaluating spine and pelvic flexibility during the sit-and-reach (SR) test. Thirty adults performed the SR twice on separate days. The SR test was captured on video and later analyzed for T, L, and P angles using the computer software angle tool. During the test, 3 markers were placed over T1, T12, and L5 vertebrae to identify T, L, and P angles. Intraclass correlation coefficient (ICC) indicated a very high internal consistency (between trials) for T, L, and P angles (0.95-0.99); thus, the average of trials was used for test-retest (between days) reliability. Mean (+/- SD) values did not differ between days for T (51.0 +/- 14.3 vs. 52.3 +/- 16.2 degrees), L (23.9 +/- 7.1 vs. 23.0 +/- 6.9 degrees), or P (98.4 +/- 15.6 vs. 98.3 +/- 14.7 degrees) angles. Test-retest reliability (ICC) was high for T (0.96) and P (0.97) angles and moderate for L angle (0.84). Both intrarater and interrater reliabilities were high for T (0.95, 0.94) and P (0.97, 0.97) angles and moderate for L angle (0.87, 0.82). Thus, the computer software angle tool is a highly objective method for assessing spine and pelvic flexibility during a video-captured SR test.