A system and method for analyzing and improving the performance of an athletic motion such as a golf swing requires: instrumenting a user with inertial sensors and video cameras and monitoring a golf swing or such other athletic motion of interest; drawing upon and contributing to a vast library of performance data for analysis of the test results; the analysis including scoring pre-defined parameters relating to component parts of the motion and combining the parameter scores to yield a single, kinetic index score for the motion; providing a real-time, information rich, graphic display of the results in multiple, synchronized formats including video, color coded and stepped frame animations from motion data, and data/time graphs; and based on the results prescribing a user-specific training regime with exercises selected from a library of standardized exercises using standardized tools and training aids.