In this contribution a framework for digital human modelling using optimal control of a biomechanical multibody model is presented. The skeleton of the human body is represented as a multibody system, actuated by simplified Hill muscles. Motions of the digital human model are generated by optimal control with different objective functions. The optimal control problem is discretized by the DMOCC approach, using a variational integrator for the constrained equations of motion. With this approach, the task of “lifting of a box from a lower to a higher position” is simulated as a test example. Both arms are modeled with seven degrees of freedom each, actuated by 29 muscles. In the optimal control problem an arbitrary grasp position is included, as well as frictional contact between the box and the hand.