DescriptionWhile the neuromuscular components involved in moving human joints are well known, there is no unifying model describing how they accomplish it. The dynamics of each individual neuromuscular component, from the brain structures, including cerebral cortex and sub-cortical areas, to the spinal cord, to the contractual apparatus have been formulated previously, but they have not been thoroughly tested, nor integrated into a holistic model of movement. This thesis combined these formulations into a single brain-spinal cord-muscle (BSM) model that illustratesmotion planning by interactions between these brain components . Movement plans originating in the cerebral cortex are processed in the descending motor pathways: brainstem, cerebellum, and spinal circuitry. Execution is coordinated by activation of agonist and antagonist muscle groups, mostly with closed-loop feedback control. Here, I analyzed previously publishedneuromuscular formulations by simulations. I applied several methods for combining piecemeal models of individual components into a unified control system. Results with BSM produced physiologically realistic joint outputs showing new details, not seen in previous models. The BSM model can be useful for detailed analysis of any biological component involved with motion generation, and can help in understanding the underlying causes of motor impairments.