LAUSR

ABSTRACT Background Proprioception deficit has been suggested as a possible mechanism contributing for the impaired postural control in low back pain (LBP) patients. Whether proprioception deficit is a result of or a cause of LBP has not been investigated. Objective The purpose of this study was to compare proprioceptive postural control strategies between prolonged standing induced low back pain developers (PDs) and non-pain developers (NPDs). Method Thirty-two healthy subjects performed 1-h prolonged standing and their ratings of perceived LBP have been recorded. Eight quiet standing trials for 60 s performed immediately before and after the prolonged standing. Postural control was challenged by muscle vibration and different postural conditions during quiet standing. Data were recorded using a force platform. Results Forty percentage of participants is classified as PD. Before the prolonged standing, relative proprioceptive weighting was greater in the PD compared to NPD group (P = .029). Main effect of postural condition (F1,24 = 5.21, P = .032) and interaction of time by group (F1,24 = 8.08, P = .009) were significant for COP displacement in anteroposterior direction. Interaction of postural condition by group (F1,26 = 7.82, P = .010) and time by group (F1,26 = 9.71, P = .004) were significant for COP displacement in mediolateral direction. Main effect of postural condition (F1,26 = 6.31, P = .018) and interaction of postural condition by group (F1,26 = 7.07, P = .013) were significant for mean velocity in mediolateral direction. Conclusion The PD group has altered proprioceptive postural control strategies before and after prolonged standing. Proprioception deficit should not be considered to be solely an adaptive response and may be causal for LBP development.