The aim of this work is to improve musculoskeletal-based models of the
upper-limb Wrench Feasible Set i.e. the set of achievable maximal wrenches at
the hand for applications in collaborative robotics and computer aided
ergonomics. In particular, a recent method performing wrench capacity
evaluation called the Iterative Convex Hull Method is upgraded in order to
integrate non dislocation and compression limitation constraints at the
glenohumeral joint not taken into account in the available models. Their
effects on the amplitude of the force capacities at the hand, glenohumeral
joint reaction forces and upper-limb muscles coordination in comparison to the
original iterative convex hull method are investigated in silico. The results
highlight the glenohumeral potential dislocation for the majority of elements
of the wrench feasible set with the original Iterative Convex Hull method and
the fact that the modifications satisfy correctly stability constraints at the
glenohumeral joint. Also, the induced muscles coordination pattern favors the
action of stabilizing muscles, in particular the rotator-cuff muscles, and
lowers that of known potential destabilizing ones according to the literature.Comment: 30 pages (double spacing), 10 figures, 2 table