Accuracy of pelvis repositioning in individuals with and without low back pain

Proprioception allows the body to maintain proper orientation during static and dynamic activities. In the upper and lower extremities, research has demonstrated a loss of some aspects of proprioception and improvement in proprioception with retraining. It was hypothesized that persons with low back pain lose some elements of proprioception, although research in this area is relatively new. One aspect of proprioception, repositioning accuracy, was examined in this study. The primary purpose of this study was to compare repositioning accuracy of individuals with CLBP and healthy controls. Specifically, the ability to reposition the pelvis into a neutral position was examined in standing and seated positions. A secondary purpose of the study was to examine the inter-relationships between low back pain, repositioning accuracy and physical measurements. The ability to repositioning the pelvis into neutral in both standing and seated positions was tested in 19 volunteers aged 35-55 years old from the University of Tennessee at Knoxville and surrounding community. The participants were divided into two groups based on their Oswestry Low Back Pain Disability Questionnaire score (ODQ). Individuals with an ODQ score of zero were placed in the control group (n = 10). The chronic low back pain group (CLBP; n = 9) included individuals with an ODQ score greater than zero. The groups were similar with regards to age, height, weight, and body mass index. An electronic goniometer (elgon) was used to measure total lumbar range of motion (TROM), baseline neutral position, and neutral repositioning in both standing and seated positions. Each participant underwent a neutral spine training session following anthropometric, flexibility and strength measurements. Standing TROM was calculated as the sum of extreme anterior tilt and extreme posterior tilt. Following TROM testing, baseline standing neutral spine position was recorded for each individual. The participants then attempted to replicate their standing neutral position. Repositioning error was calculated as the absolute difference between the baseline neutral position and the repositioned neutral position. The same protocol was repeated in an unsupported seated position. The results of the repeated measures ANOVA demonstrated no significant differences in repositioning accuracy between the CLBP group and the healthy control group in either standing or seated positions. However, there was a significant difference between the standing and seated positions for the sample (p < 0.05). Overall, for all subjects, the mean absolute repositioning error was greater in a seated position than in standing. In addition, the groups were no statistically different in TROM or baseline neutral positions in either standing or seated positions. To examine the difference in lumbar lordosis before and after neutral spine training, a single factor (time) repeated measures ANOVA was performed on the measurements obtained with the flexible ruler. There was a significant time effect for both the CLBP and control groups; the lumbar lordosis measures were significantly reduced with neutral spine posture. The between group effect was not significant. MANOVA indicated significant differences between the groups for trunk extension strength and abdominal strength. In both cases the CLBP group had statistically weaker trunk extension and trunk flexion strength.