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Published on: December 14, 2011
Soft tissue wobbling affects trunk dynamic response in sudden perturbations.
B Bazrgari1, M A Nussbaum, M L Madigan
1Department of Industrial and Systems Engineering, Virginia Tech, 250 Durham Hall (0118), Blacksburg, VA 24061, USA.
Journal of Biomechanics
|October 5, 2010
Summary
Soft tissue wobbling significantly reduces impact forces on the spine during sudden trunk perturbations. This effect lessens the demands on the neuromuscular system for maintaining stability.
Area of Science:
- Biomechanics
- Human Biodynamics
- Finite Element Analysis
Background:
- Soft tissue wobbling is known to mitigate impact forces on lower limb joints.
- The effect of soft tissue wobbling on the trunk's dynamic response to perturbations remains less understood.
Purpose of the Study:
- To investigate if soft tissue wobbling affects the trunk's dynamic response to sudden perturbations.
- To assess the influence of modeling the rod-harness assembly on trunk dynamic response predictions.
Main Methods:
- Experimental testing on three healthy males subjected to anterior trunk perturbations at varying velocities.
- Measurement of trunk kinematics and kinetics.
- Development and application of a nonlinear active-passive finite element model of the human trunk.
Main Results:
- Model predictions closely matched experimental data when accounting for soft tissue wobbling and the rod-harness assembly (correlation coefficient ρ>0.97).
- Neglecting these factors significantly increased prediction errors.
- Trunk wobbling and connecting elements reduced impact loads on the spine by 33-90 N, especially at higher perturbation velocities.
Conclusions:
- Soft tissue wobbling and the apparatus used for perturbations substantially attenuate impact forces transferred to the spine.
- These factors reduce predicted neuromuscular system demands for spinal control and stability.
- Future biodynamic models of the human trunk should incorporate these effects for accurate neuromuscular behavior estimation.
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