Thoracolumbar proprioception in individuals with and without low back pain: Intratester reliability, clinical applicability, and validity

Study Design: Repeated measures design of active spinal position sense in individuals with and without low back pain (LBP). Objectives: Reproducibility and validity evaluation of thoracolumbar proprioception measurement. Background: Proprioception studies in peripheral joints and the spine suggest that there may be proprioception deficits due to injury, pain, or degeneration. Kinesthetic retraining may be useful in rehabilitation of patients with LBP, but appropriate measures are required to objectively quantify spinal proprioception. Methods and Measures: Active-target reproduction in the sagittal, horizontal, and coronal planes was assessed (3 separate occasions for 18 asymptomatic volunteers and 2 occasions for 62 patients with LBP). Repositioning accuracy was expressed as absolute errors (AE) and variable errors (VE). Reliability was analyzed with intraclass correlation coefficient (ICC) and precision with standard error of measurement (SEM) and calculation of the smallest detectable difference (SDD) index. Repeated measures ANOVA and correlations were used for within-group comparisons and discriminant analysis for between-group comparisons. Results: Reproducibility was better for the asymptomatic group, with AE for flexion and rotation being the most reliable (ICC = 0.76-0.80, SEM = 0.91degrees-1.34degrees). SDDs were high for all tests, suggesting limited clinical applicability. Reproducibility for the same tests was poor-moderate (ICC = 0.31-0.64, SEM = 0.45degrees-3.90degrees) for the patient group. AE for right-side rotation could discriminate between subject groups with 83.3% specificity but only 54.8% sensitivity. Conclusions: Proprioception testing, with the methods employed, did not demonstrate good measurement properties in a sample of patients with recurrent LBP. Neither could it sufficiently discriminate between individuals with and without LBP. Possible reasons for these findings are discussed.