title: How back-muscle fatigue influences lumbar curvature.
abstract: BACKGROUND
  Back-muscle fatigue and lumbar curvature are related to low back pain, but the relation between them is unknown.
  
  
  OBJECTIVE
  To clarify whether lumbar curvature changes with back-muscle fatigue.
  
  
  METHODS
  Prospective pseudorandomized.
  
  
  METHODS
  Laboratory.
  
  
  METHODS
  13 healthy men without low back pain.
  
  
  METHODS
  To induce back-muscle fatigue, subjects performed a repetitive prone back-extension exercise from 45 degrees to 0 degrees until exhaustion and then rested 10 min. They performed this exercise 3 times.
  
  
  METHODS
  Before the trial and after each exercise, lumbar curvature was measured with a Spinal Mouse.
  
  
  RESULTS
  After back-muscle fatigue, lumbar curvature decreased significantly (P < .01). This decrease occurred at L4-S1, which was defined as the lower spine. On the contrary, curvature of the upper lumbar spine, at Th12-L4, did not decrease.
  
  
  CONCLUSIONS
  Lumbar curvature, especially the lower portion, decreased with back-muscle fatigue induced by prone back-extension exercise.
authors: Health Science Department, Hiroshima University, Hiroshima, Japan.
authors: Yukio
authors: Y
authors: Takihara
authors: Yukio
authors: Y
authors: Urabe
authors: Gaston Ariel
authors: GA
authors: Nishiwaki
authors: Kosuke
authors: K
authors: Tanaka
authors: Koji
authors: K
authors: Miyashita
mesh_terms: D015444:Exercise / Q000502:physiology*; D006801:Humans; D008159:Lumbar Vertebrae / Q000033:anatomy & histology*; D008297:Male; D018763:Muscle Fatigue / Q000502:physiology*; D018482:Muscle, Skeletal / Q000503:physiopathology*; D010807:Physical Endurance / Q000502:physiology; D011446:Prospective Studies; D011897:Random Allocation; D055815:Young Adult