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How back-muscle fatigue influences lumbar curvature
Yukio Takihara1, Yukio Urabe, Gaston Ariel Nishiwaki
1Health Science Department, Hiroshima University, Hiroshima, Japan.
Context:
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.
Design:
Prospective pseudorandomized.
Setting:
Laboratory.
Participants:
13 healthy men without low back pain.
Intervention:
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.
Main Outcome Measures:
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.
Conclusion:
Lumbar curvature, especially the lower portion, decreased with back-muscle fatigue induced by prone back-extension exercise.
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