title: Effects of experimentally induced low back pain on the sit-to-stand movement and electroencephalographic contingent negative variation.
abstract: It is becoming increasingly evident that people with chronic, recurrent low back pain (LBP) exhibit changes in cerebrocortical activity that associate with altered postural coordination, suggesting a need for a better understanding of how the experience of LBP alters postural coordination and cerebrocortical activity. To characterize changes in postural coordination and pre-movement cerebrocortical activity related to the experience of acutely induced LBP, 14 healthy participants with no history of LBP performed sit-to-stand movements in 3 sequential conditions: (1) without experimentally induced LBP; NoPain1, (2) with movement-associated LBP induced by electrocutaneous stimulation; Pain, and (3) again without induced LBP; NoPain2. The Pain condition elicited altered muscle activation and redistributed forces under the seat and feet prior to movement, decreased peak vertical force exerted under the feet during weight transfer, longer movement times, as well as decreased and earlier peak hip extension. Stepwise regression models demonstrated that electroencephalographic amplitudes of contingent negative variation during the Pain condition significantly correlated with the participants' change in sit-to-stand measures between the NoPain1 and Pain conditions, as well as with the subsequent difference in sit-to-stand measures between the NoPain1 and NoPain2 conditions. The results, therefore, identify the contingent negative variation as a correlate for the extent of an individual's LBP-related movement modifications and to the subsequent change in movement patterns from before to after the experience of acutely induced LBP, thereby providing a direction for future studies aimed to understand the neural mechanisms underlying the development of altered movement patterns with LBP.
authors.affiliation: Department of Rehabilitation and Movement Science, University of Vermont, 305 Rowell Building, 106 Carrigan Drive, Burlington, VT 05405, USA. JJacobs@uvm.edu
authors.forename: Jesse V
authors.initials: JV
authors.lastname: Jacobs
authors.forename: Chie
authors.initials: C
authors.lastname: Yaguchi
authors.forename: Chizuru
authors.initials: C
authors.lastname: Kaida
authors.forename: Mariko
authors.initials: M
authors.lastname: Irei
authors.forename: Masami
authors.initials: M
authors.lastname: Naka
authors.forename: Sharon M
authors.initials: SM
authors.lastname: Henry
authors.forename: Katsuo
authors.initials: K
authors.lastname: Fujiwara
mesh_terms: D000328:Adult; D002540:Cerebral Cortex / Q000502:physiology; D003265:Contingent Negative Variation / Q000502:physiology*; D004569:Electroencephalography / Q000379:methods; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000209:etiology / Q000503:physiopathology* / Q000523:psychology; D008297:Male; D008875:Middle Aged; D009068:Movement / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D011187:Posture / Q000502:physiology*; D055815:Young Adult