My laboratory's goal is to create useful computational models of how humans move and physically interact with their environment. The focus is not on black-box modeling of movement data. Rather, it is on modeling the underlying system itself, as a biological machine: the motors (muscles), structures (skeleton and connective tissues), sensors (mechanoreceptors), and software (neural control). By modeling the underlying sensorimotor system we could achieve better generalization to novel situations and gain fundamental insights into biological principles. I will describe recent progress in this area. I will discuss questions such as: How should we simulate the dynamics of human movement? How do muscles work? How does the brain control such a complex machine? I will also describe applications in computer graphics, robotics, and human health.