For efficient design of gestural user interfaces both performance and fatigue characteristics of movements must be understood. We are developing a novel method that allows for biomechanical analysis in conjunction with performance analysis. We capture motion data using optical tracking from which we can compute performance measures such as speed and accuracy. The measured motion data also serves as input for a biomechanical simulation using inverse dynamics and static optimization on a full-body skeletal model. The simulation augments the data by biomechanical quantities from which we derive an index of fatigue. We are working on an interactive analysis tool that allows practitioners to identify and compare movements with desirable performance and fatigue properties. We show the applicability of our methodology using a case study of rapid aimed movements to targets covering the 3D movement space uniformly.