ABSTRACT
BACKGROUND: Various inputs of proprioception have been identified and shown to influence low back proprioception sense. OBJECTIVE: To investigate the effect of disrupting proprioception on lumbar spine repositioning error during forward bending. METHOD: Healthy-subjects (n=28) and patients with non-specific chronic low-back pain (n=10) aged between 20-50 years. Subjects performed 5 repetitions of a lumbar repositioning task targeting 30° of trunk-forward-bending from a seated-position with different proprioceptive disturbances administered to the low back. Video analysis of skin reflective markers measured lumbar spine range-of-motion. A control-task was performed without any proprioceptive disturbance, while the remaining 4 tasks were electro-stimulation, vibration, taping and sitting on an unstable surface. RESULTS: The healthy group showed significantly altered repositioning error when compared with the control task (p=0.004): control-task vs. taping-task, vibration-task and unstable-sitting. In the NS-CLBP group, one motor-task showed significant difference in control-task vs. taping-task (p=0.004). Comparison between the NS-CLBP and matched-healthy groups revealed that the NS-CLBP subjects had larger repositioning-error (p=0.009) for control, taping and vibration tasks. CONCLUSIONS: Proprioceptive disturbances had the most significant effect in increasing repositioning-error among healthy subjects. The between-groups analysis confirmed evidence consistent with the literature of greater repositioning-error in people with NS-CLBP than healthy subjects.
