Today the field of neuromuscular simulations is widely used to understand the underlying dynamics of the movement of living beings, from gait research, treatment of patient with gait problems, to the teaching of physicians and the development of ergonomic furniture. During the last years several new platforms have been developed which can provide powerful simulation using complex models. Several new models have been released which has the potential to provide new knowledge. There has also been a shift in the use of neuromuscular simulations from an academic to be used in clinical investigation. Today we can see the next shift in musculoskeletal simulations were the area is used to design chairs for a better ergonomic sitting position to design of new exercise machines. This work has been carried out in four different fields; first a Matlab toolbox was developed to close the gap between the motion capture tools to the simulations environment. Next two new knee joints descriptions were developed and evaluated based on two different modeling ideas. In the last two chapters I show how a finite element simulation can be driven with neuromuscular data and the use of scientific visualization to visualize neuromuscular simulations result in a clearer manner.