 This is a preliminary study to evaluate the possible use of transcranial magnetic stimulation TMS, together with exercise, for rehabilitation of chronic stroke patients. It will identify the optimum stimulation settings within the limits of current safety guidelines to be used in a later rehabilitation study and confirm the safety of the procedure at these settings. Some previous studies using TMS to treat movement disorders such as Parkinsons disease have shown improvement in motor function; others have not. The results of this study may provide information to help researchers design better rehabilitation treatments after stroke. 