Methods and apparatus based on vibromyography technology are provided that overcome the substantial limitations of current VMG muscle assessment approaches. Specifically, embodiments of the invention provide a means by which clinicians and trainers can perform real-time muscle assessment during typical functional activities (activities involving substantial human movements). In some embodiments, the invention allows the artisan to simultaneously measure muscle forces being generated by complementary, supplementary, and/or antagonistic muscle pairs such that real-time muscle effort ratios can be calculated. In some embodiments, the measurements provide a means by which clinicians and trainers can diagnose musculo-skeletal injuries and pains associated with muscle imbalances.