Journal of Back and Musculoskeletal Rehabilitation 26 (2013) 381–387 381 DOI 10.3233/BMR-130396 IOS Press Effects of proprioceptive disruption on lumbar spine repositioning error in a trunk forward bending task Benjamin Hidalgo ∗ , François Gobert, Dominique Bragard and Christine Detrembleur Institute of Neuroscience, Faculty of Motor Sciences, University of Louvain, Brussels, Belgium 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 dif- ference 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. Keywords: Kinematics, low back pain, proprioception, repositioning error, spine 1. Introduction Low-back pain is a common musculoskeletal disor- der [1–3]. The population most at risk is active peo- ple in industrialized countries [2,3]. Up to 75% of the working population suffers at least once in their lives from low-back pain and approximately 14% suf- fer pain lasting for more than 2 weeks [1–3]. In the United-States, low-back pain ranks second among the reasons for seeking medical attention [3] leading to im- portant medical costs and economic consequences [1– 5]. ∗ Address for correspondence: Benjamin Hidalgo, Université Catholique de Louvain, Institute of Neuroscience, Avenue Mounier, 53–B1.53.04, 1200 Brussels, Belgium. Tel.: +32 2 764 53 75; Fax: +32 2 764 53 60; E-mail: benjamin.hidalgo@uclouvain.be. The sources of non-specific low-back pain (NS- LBP) are multiple and lack diagnostic precision in 80% of cases [2,3]. The Postural-structural-biomechanical model is currently used for evaluation of low-back pain and rationalizes the application of physical therapy and/or pharmacological treatment; however this model has recently been questioned [4]. Indeed, medical im- ages and clinical tests do not always correlate with low-back pain status [4–7]. Therefore, new assessment tools are necessary to help in understanding the prob- lematic of NS-LBP patients [5–7]. Motor control disorders are common problems in chronic NS-LBP. The hypothetical underlying mecha- nism could be a deficiency of proprioception in these patients [8–13]. Proprioception is considered as “the knowledge of the positions of body segments and the ISSN 1053-8127/13/$27.50 c  2013 – IOS Press and the authors. All rights reserved AUTHOR COPY