We carried out an exploratory study to evaluate the safety of the Harmony upper body exoskeleton during stroke rehabilitation in a clinical setting. This robot contains a novel arrangement of active degrees of freedom about the shoulder complex that should be evaluated for safe interaction before assessing clinical efficacy. This study was performed with a fifty-eight year old male and began twenty-seven months after ischemic stroke. The subject's shoulder girdle motion, glenohumeral subluxation, and muscle status were monitored over twenty-two sessions. Glenohumeral subluxation was successfully avoided throughout arm motion, and palpated scapular motion was deemed satisfactory. Active range of motion and effort duration measurements showed slight changes between early and late sessions, but no significant improvement in daily function was anticipated. Nevertheless the Harmony exoskeleton was capable of maintaining glenohumeral joint closure and proper coordination of shoulder girdle motion during several multi-joint movements in a chronic stroke subject.