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Determining The Electromyographic Fatigue Threshold Following a Single Visit Exercise Test
Published on: July 27, 2015
High cycle fatigue behaviour of functional spinal units.
Gerd Huber1, Daniel M Skrzypiec, Anke Klein
1Institute of Biomechanics, TUHH Hamburg University of Technology, Denickestrasse 15, 21073 Hamburg, Germany. g.huber@tuhh.de
Industrial Health
|October 19, 2010
Summary
Whole body vibrations pose a risk to spinal health. This study found that bone mineral density and endplate area predict fatigue strength in older donors, crucial for understanding vibration injuries.
Area of Science:
- Biomechanics
- Spinal Pathologies
- Occupational Health
Background:
- Vibrations are a known risk factor for spinal pathologies, but mechanisms remain unclear.
- In vivo data on spinal loading from vibrations is scarce, necessitating in vitro studies.
- Numerical models require accurate fatigue strength data for spinal loading estimations.
Purpose of the Study:
- To determine the fatigue strength of spinal specimens under simulated vibration loading.
- To investigate the influence of age and posture on spinal fatigue strength.
- To identify predictors of spinal failure under vibratory loads.
Main Methods:
- In vitro testing of human spinal specimens from young and old male donors.
- Cyclic compression loading (300,000 cycles at 2 kN) simulating vibration exposure.
- Assessment of bone mineral density (BMD) and endplate area using CT scans.
Main Results:
- Young specimens in neutral posture showed no failure.
- Four older specimens with low BMD failed, indicating reduced fatigue strength.
- The product of endplate area and BMD effectively predicted fatigue strength in older donors.
- Two young specimens in flexed posture failed, one possibly due to low BMD, the other unexplained.
Conclusions:
- Bone mineral density and endplate area are critical factors for predicting spinal fatigue strength, particularly in older individuals.
- These findings are relevant for understanding and mitigating risks associated with whole body vibration exposure.
- Further research is needed to clarify the impact of spinal flexion on fatigue failure under vibration.
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