Background: The purpose of this study was to observe and quantify the effect of aging and the long-term practice of Tai Chi on movement control, indicated by both performance-outcome (temporal) and performance-production (amplitude) measures, on a multi-planar stand-reaching (i.e. functional) task. We hypothesized that younger controls and older Tai Chi practitioners would perform better than healthy, older non-practitioners. Methods: Thirty-five healthy adults participated in this cross-sectional study (12 Tai Chi practitioners, 11 age-matched older non-practitioners and 12 young controls). Subjects performed flexion- and abduction-reaching tasks guided by a preparatory cue, which was followed by a second cue to initiate movement to touch the target as quickly and as accurately as possible. Wireless sensors were used to collect surface EMG and acceleration data to render performance-outcome (reaction time, burst duration, time-to-peak and movement time) and performance-production (normalized EMG amplitude and peak acceleration) measures. Results: Young subjects and Tai Chi practitioners manifested significantly faster reaction times, shorter burst durations, shorter times to peak and overall quicker movement time, with correspondingly greater normalized EMG amplitudes and larger peak accelerations, as compared to older adults (p < 0.001 and p < 0.05, respectively, for all variables). Relative effect computations (i.e. effect of Tai Chi expressed as a percentage of the effect of aging) showed that age-matched Tai Chi practitioners exhibited approximately 20–60% (flexion), and 20–100% (abduction) improvement in reaching task performance. Conclusion: Tai Chi practitioners displayed better movement control than non-practicing individuals on a relatively challenging and comparatively more functional stand-reaching task.