title: Ultrasound evidence of altered lumbar connective tissue structure in human subjects with chronic low back pain.
abstract: BACKGROUND
  Although the connective tissues forming the fascial planes of the back have been hypothesized to play a role in the pathogenesis of chronic low back pain (LBP), there have been no previous studies quantitatively evaluating connective tissue structure in this condition. The goal of this study was to perform an ultrasound-based comparison of perimuscular connective tissue structure in the lumbar region in a group of human subjects with chronic or recurrent LBP for more than 12 months, compared with a group of subjects without LBP.
  
  
  METHODS
  In each of 107 human subjects (60 with LBP and 47 without LBP), parasagittal ultrasound images were acquired bilaterally centered on a point 2 cm lateral to the midpoint of the L2-3 interspinous ligament. The outcome measures based on these images were subcutaneous and perimuscular connective tissue thickness and echogenicity measured by ultrasound.
  
  
  RESULTS
  There were no significant differences in age, sex, body mass index (BMI) or activity levels between LBP and No-LBP groups. Perimuscular thickness and echogenicity were not correlated with age but were positively correlated with BMI. The LBP group had approximately 25% greater perimuscular thickness and echogenicity compared with the No-LBP group (ANCOVA adjusted for BMI, p<0.01 and p<0.001 respectively).
  
  
  CONCLUSIONS
  This is the first report of abnormal connective tissue structure in the lumbar region in a group of subjects with chronic or recurrent LBP. This finding was not attributable to differences in age, sex, BMI or activity level between groups. Possible causes include genetic factors, abnormal movement patterns and chronic inflammation.
authors: Department of Neurology, Given Building, University of Vermont, Burlington, VT 05405, USA. helene.langevin@uvm.edu
authors: Helene M
authors: HM
authors: Langevin
authors: Debbie
authors: D
authors: Stevens-Tuttle
authors: James R
authors: JR
authors: Fox
authors: Gary J
authors: GJ
authors: Badger
authors: Nicole A
authors: NA
authors: Bouffard
authors: Martin H
authors: MH
authors: Krag
authors: Junru
authors: J
authors: Wu
authors: Sharon M
authors: SM
authors: Henry
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D002908:Chronic Disease; D003238:Connective Tissue / Q000000981:diagnostic imaging*; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000000981:diagnostic imaging*; D008161:Lumbosacral Region; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D012008:Recurrence; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D014463:Ultrasonography