The five-repetition sit-to-stand test: evaluation of a simple and objective tool for the assessment of degenerative pathologies of the lumbar spine

OBJECTIVE Recently, objective functional tests have generated interest since they can supplement an objective dimension to clinical assessment. The five-repetition sit-to-stand (5R-STS) test is a quick and objective tool that tests movements frequently used in everyday life. The aim of this prospective study was to evaluate the validity and reliability of the 5R-STS test in patients with degenerative pathologies of the lumbar spine. METHODS Patients and healthy volunteers completed the standardized 5R-STS, Roland-Morris Disability Questionnaire (RMDQ), Oswestry Disability Index (ODI), visual analog scale (VAS) for back and leg pain, and EQ-5D for health-related quality of life (HRQOL). To assess convergent validity, the 5R-STS test times were correlated with these questionnaires. RESULTS Overall, 157 patients and 80 volunteers were enrolled. Direct correlation with RMDQ (r = 0.49), ODI (r = 0.44), and VAS for back pain (r = 0.31) and indirect correlation with the EQ-5D index (r = -0.41) were observed (p < 0.001). The 5R-STS test showed no correlation with VAS for leg pain and EQ-5D VAS (p > 0.05). In 119 individuals, the 5R-STS test demonstrated excellent test-retest reliability with an intraclass correlation coefficient of 0.98. The upper limit of normal, distinguishing patients with and without objective functional impairment, was identified as 10.35 seconds. A severity stratification classified patients with test times of 10.5-15.2, 15.3-22.0, or greater than 22.0 seconds as having mild, moderate, or severe functional impairment, respectively. CONCLUSIONS The 5R-STS test is a simple and effective tool to describe objective functional impairment. A patient able to perform the test in 10.4 seconds can be considered to have no relevant objective functional impairment.