A biomechanical model of the thumb that effectively replicates endpoint forces produced by human subjects and measured in anatomical specimens

Current biomechanical models of the thumb do not replicate either the maximum pinch forces produced via coordinated muscle actions by human subjects [1] or the magnitudes of the forces produced by individual muscles as quantified in cadaveric specimens [2]. However, compared to the literature, these models either underestimate the forces produced by human subjects [1] or overestimate the magnitudes quantified in cadaveric specimens [3, 4]. Specifically, the model developed by Valero-Cuevas et al (2003) was reported to be four times weaker than the endpoint forces produced during maximum effort by human subjects experimentally [1]. In contrast, Towles et al., (2008) reported simulated endpoint forces substantially greater than the forces produced by individual muscles in cadaveric experiments for six of nine muscles studied. [3]. Similarly, Goehler and Murray (2010) simulated the endpoint forces produced by individual extrinsic muscles and reported results that were approximately 60% larger than the forces measured in cadavers [4].Copyright © 2012 by ASME