Effects of proprioceptive disruption on lumbar spine repositioning error in a trunk forward bending task.

Abstract

Various inputs of proprioception have been identified and shown to influence low back proprioception sense. To investigate the effect of disrupting proprioception on lumbar spine repositioning error during forward bending. 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. 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. 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.