The research question is which clinical and kinematic outcome measures best reflect motor performance recovery after a targeted upper limb treatment intervention. Aim 1 is to compare changes in outcome measures recorded before and after an upper limb intervention in stroke subjects to motor performance in healthy subjects. Aim 2 is to determine motor performance between-group differences sample size is based on knowledge of expected outcome measure mean score differences between groups. Hypothesis. 1: Specific clinical and kinematic outcome measures will be sensitive to within-group (pre-post intervention training) changes. Hypothesis. 2: Specific clinical and kinematic outcome measures will be sensitive to between-group (healthy vs. patients in enriched vs. conventional intervention groups. Sixteen chronic stroke survivors and 8 age- and sex-matched healthy controls will participate. Patients will be matched on cognitive and motor impairment levels and divided into two groups. Using an single subject (A-B-A) research design, kinematics during two pre-tests, 3 weeks apart, will be recorded for test-retest reliability. Stroke groups will practice varied upper limb reaching movements (15 45-minute sessions in 3 weeks) in environments providing different motivation/feedback levels. Pre- and post motor performance evaluations will be done with clinical tests and a Test Task with specific motor performance requirements. A Transfer Task will also be recorded. By comparing data analysis methods (3-Dimensional (3D) analysis of different markers or placements), the investigators will identify which kinematic outcome measures best reflect motor improvement in post-test and follow-up sessions (retention).