A Global Approach to Assessing Uncertainty in Biomechanical Inverse Dynamic Analysis: Mathematical Model and Experimental Validation

An important task in biomechanics is human body articulations' internal torques measurement. This is known as a kinetic or inverse-dynamics problem. Its solution requires a combination of kinematic and dynamic measurements with a biomechanical model, involving subject-related anthropometric parameters. The uncertainty-evaluation thereof is here considered. The method poses on a probabilistic model of the associated measurement system, according to the "Guide to the expression of uncertainty in measurement" general principles. We consider a comprehensive set of influence quantities, including markers' misplacement or parasite movements. The anthropometric parameters' uncertainty is discussed in detail. The proposed approach helps to identify the most influential experimental factors.