

High kinematic accuracy (maximum mean deviation ≤ 2.35° and RMSE 1.13°) and repeatability (maximum and average SD of ≤ 1.21° and 0.67°) were observed in all three rotational DOF investigated. Three cadaveric specimens were used to evaluate the kinematic and kinetic performance of the simulator during simulated motions.

The control algorithm of the simulator was implemented using three parallel running independent control loops, which regulate the forces of individual muscles in the respect DOF and work asynchronously in disparate sequences adapted to specific motions (abduction, flexion/extension and rotation). A physiologic shoulder simulator, driven using simulated muscle force, was developed to dynamically realize accurate kinematic control in all three rotational degrees of freedom (DOF) under physiological kinetic boundaries. The purpose of the present study was to develop a novel active in-vitro shoulder simulator to emulate all forms of planar and non-planar glenohumeral motions with active muscle simulation on cadaver specimens or shoulder models and to critically evaluate its performance.
