Usually a visual and sometimes an auditory stimulus received by the sensory cortex passes to the motor cortex, causing it to co-ordinate impulses from the cerebellum and ultimately stimulate several hundred neurons in the kinesthetic pathway. The resulting muscle contractions cause the organism to perform a predifined movement.
Thats Bob Elton walking away, head hung in shame after being told to F** off by the manual shifters. Mann.. he should use an electric wheelchair rather than perform the complex calculations needed to walk.