title: Minimal influence of facet joint anesthesia on isokinetic muscle performance in patients with chronic degenerative low back disorders.
abstract: METHODS
  Experimental design.
  
  
  OBJECTIVE
  To examine the influence of pain reduction after facet joint injections on isokinetic back muscle performance.
  
  
  BACKGROUND
  Methods for evaluating the effect of facet joint injections vary. Recent studies base their results solely on the patient's subjective opinion and suggest a need for more objective, concrete, and reliable measurements.
  
  
  METHODS
  Eighty-seven patients with a degenerative low back disorder (49 women and 38 men; mean age, 48 years; range, 22-79) who had facet joint injections as a part of preoperative evaluation participated. The mean duration of symptoms was 12.3 years (range, 1-45). The patients underwent isokinetic trunk flexor and extensor muscle strength testing at angular velocities of 60 deg/sec and 120 deg/sec. They performed two tests before the facet joint injections (to eliminate learning effect). All patients had bilateral facet joint injections at L5-S1. Those who did not report pain relief had additional injections at L4-L5. The flexion-extension test was repeated 15 minutes after each injection. Pain and fear were registered on visual analog scales.
  
  
  RESULTS
  All 87 patients could perform the isokinetic tests. For extension at 60 deg/sec, a significant improvement was found between the two pretests (P < 0.05). Pain increased significantly from the first to the second pretest (P = 0.02), and a significant decrease in pain was found after the first injection (P = 0.0001). Fear decreased between each test, with a significant decrease after the first injection. No significant change was found for the muscle strength measurements after facet joint anesthesia. There were only weak correlations between decrease in pain and alteration in muscle performance, ranging from 0.06 to 0.37.
  
  
  CONCLUSIONS
  Pain reduction after facet joint injections did not influence isokinetic muscle performance in patients with degenerative low back disorders.
authors.affiliation: Biomechanics Laboratory and Departments of Physiotherapy and Radiology, National Hospital Orthopaedic Department, University of Oslo, Norway. inger.holm@klinmed.uio.no
authors.forename: I
authors.initials: I
authors.lastname: Holm
authors.forename: A
authors.initials: A
authors.lastname: Friis
authors.forename: J I
authors.initials: JI
authors.lastname: Brox
authors.forename: R
authors.initials: R
authors.lastname: Gunderson
authors.forename: H
authors.initials: H
authors.lastname: Steen
mesh_terms: D000328:Adult; D000368:Aged; D000777:Anesthetics / Q000494:pharmacology*; D002908:Chronic Disease; D017079:Exercise Tolerance / Q000187:drug effects / Q000502:physiology; D005260:Female; D006801:Humans; D007596:Joints / Q000187:drug effects* / Q000473:pathology / Q000503:physiopathology; D017116:Low Back Pain / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology; D008159:Lumbar Vertebrae / Q000187:drug effects* / Q000473:pathology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009068:Movement / Q000187:drug effects* / Q000502:physiology; D018908:Muscle Weakness / Q000188:drug therapy* / Q000209:etiology / Q000503:physiopathology; D018482:Muscle, Skeletal / Q000187:drug effects / Q000503:physiopathology
chemical_list: D000777:Anesthetics