Lumbosacral repositioning accuracy in standing posture: a combined electrogoniometric and videographic evaluation

Objective. To provide a new method of measuring repositioning accuracy in the lumbosacral spine in a standing position. Design. A test-retest and parallel-forms reliability testing was performed. Background. The contribution of proprioception to lumbar muscle function and to the stability of the lumbar spine is relatively unknown. Method. A piezoresistive electrogoniometer attached to the skin over the sacrum and a three-dimensional video analysis system with reflective markers on anatomical landmarks were both employed to measure the repositioning accuracy of pelvic tilting in standing. Eleven subjects without low back pain participated in this study. Results. The overall mean repositioning accuracy was 1.87 degrees. Probability values from repeated measures ANOVA revealed no significant mean absolute error (AE) differences between sessions. Correlation coefficients between electrogoniometer and 3-D video analysis measurements of position sense ranged from 0.84 to 0.97. Conclusions. The proposed instruments and method are adequate for measuring lumbosacral repositioning accuracy. Healthy subjects are capable of repositioning their pelvis and back precisely.