All of those that knew Nick Davey would have been saddened and shocked by the news of his untimely death early this year. This lecture will review the contributions made by Nick to our understanding of the human motor system and the impact of central nervous system disorders. An early project involved the role of the muscle spindle and its gamma motoneurone innervation in the control of movement. The discharges of gamma motoneurones became synchronised following acute spinal cord section in the cat and that synchrony was dependent specifically on the integrity of descending monoaminergic tracts (Davey & Ellaway, 1988). The work led to studies of motoneurone discharge in Parkinsons disease. The finding also had implications for human spinal cord injury and was the starting point for Nicks many contributions to the impact of spinal cord injury on the voluntary control of skeletal muscle in man (Davey et al. 1990). Research often receives a boost with the emergence of new techniques. Nick was quick to exploit the potential of transcranial magnetic stimulation of the brain to test the integrity of the corticospinal tact in spinal cord injury and relate it to deficit in voluntary control of movement. The use of TMS led to an understanding of how the surviving connections from brain to muscle adapt to spinal cord injury and how this plasticity of central nervous system function may impact on any residual ability to move (Davey et al. 1998). It led to the expectation that a certain amount of recovery from spinal cord injury might be possible if this plasticity could be manipulated. Most recently his research showed that magnetic stimuli repeated at low rates and with a specific pattern can have a therapeutic effect. Clinical assessments and functional tests of motor performance improved and these were accompanied by physiological changes in the pathway from the motor cortex to motoneurones (Belci et al. 2004). A practical application of his research came in a Clinical Initiative funded by the International Spinal Research Trust to develop improved physiological tools for the assessment of the level and completeness of spinal cord injury in terms of sensorimotor function (Ellaway et al. 2004). Nick Daveys contributions to understanding sensorimotor systems and the impact of disease and stress were not limited to spinal cord injury. They included studies on arthritis, chronic fatigue, back pain, schizophrenia and even the weightless conditions experienced in parabolic aircraft flight.