title: Multifidus muscle recovery is not automatic after resolution of acute, first-episode low back pain.
abstract: METHODS
  A clinical study was conducted on 39 patients with acute, first-episode, unilateral low back pain and unilateral, segmental inhibition of the multifidus muscle. Patients were allocated randomly to a control or treatment group.
  
  
  OBJECTIVE
  To document the natural course of lumber multifidus recovery and to evaluate the effectiveness of specific, localized, exercise therapy on muscle recovery.
  
  
  BACKGROUND
  Acute low back pain usually resolves spontaneously, but the recurrence rate is high. Inhibition of multifidus occurs with acute, first-episode, low back pain, and pathologic changes in this muscle have been linked with poor outcome and recurrence of symptoms.
  
  
  METHODS
  Patients in group 1 received medical treatment only. Patients in group 2 received medical treatment and specific, localized, exercise therapy. Outcome measures for both groups included 4 weekly assessments of pain, disability, range of motion, and size of the multifidus cross-sectional area. Independent examiners were blinded to group allocation. Patients were reassessed at a 10-week follow-up examination.
  
  
  RESULTS
  Multifidus muscle recovery was not spontaneous on remission of painful symptoms in patients in group 1. Muscle recovery was more rapid and more complete in patients in group 2 who received exercise therapy (P = 0.0001). Other outcome measurements were similar for the two groups at the 4-week examination. Although they resumed normal levels of activity, patients in group 1 still had decreased multifidus muscle size at the 10-week follow-up examination.
  
  
  CONCLUSIONS
  Multifidus muscle recovery is not spontaneous on remission of painful symptoms. Lack of localized, muscle support may be one reason for the high recurrence rate of low back pain following the initial episode.
authors.affiliation: Department of Physiotherapy, University of Queensland, Brisbane, Australia.
authors.forename: J A
authors.initials: JA
authors.lastname: Hides
authors.forename: C A
authors.initials: CA
authors.lastname: Richardson
authors.forename: G A
authors.initials: GA
authors.lastname: Jull
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D017116:Low Back Pain / Q000534:rehabilitation* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging / Q000293:injuries / Q000473:pathology; D009135:Muscular Diseases / Q000534:rehabilitation* / Q000628:therapy; D010349:Patient Compliance; D026741:Physical Therapy Modalities; D011446:Prospective Studies; D012008:Recurrence; D016896:Treatment Outcome; D014463:Ultrasonography