In this study, 58 subjects with myofascial low back pain and 26 asymptomatic controls were evaluated according to a protocol of biomechanical analysis involving the plumbline, lateral bending dynamic roentgenograms, sacro-iliac motion palpation, lumbar motion palpation and straight-leg-raising. The outcomes of each test were blinded as to group assignment and the data was assessed statistically to derive each test's independent scores of sensitivity, specificity, predictive value and accuracy. It was observed that plumbline analysis and lateral bending dynamic roentgenograms produced the most accurate prediction of correct diagnoses. Sacro-iliac and lumbar motion palpation were nearly equivalent in predicting which cases were not symptomatic.