How back-muscle fatigue influences lumbar curvature.
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.
Takihara
Yukio
Y
Health Science Department, Hiroshima University, Hiroshima, Japan.
Urabe
Yukio
Y
Nishiwaki
Gaston Ariel
GA
Tanaka
Kosuke
K
Miyashita
Koji
K
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