E.C. FREDERICK. Synthesis, experimentation, and the biomechanics of economical movement.Med. Sci. Sports Exerc., Vol. 17, No. 1, pp. 44–47, 1985. An issue that should concern sports biomechanists is the need for more synthesis of ideas and experimental testing of those ideas. Descriptive analysis is overemphasized at present, and more stress on synthesis of existing data and experimental testing of new ideas should generate new theories that will give us insights into the mechanical behavior of structures and the kinetics and kinematics of sports movements. One area where this approach may be especially helpful is in studying the question of what makes movements energetically economical. Twenty-six behavioral and mechanical factors have been shown to have an association with the economy of movement. A synthesis should be undertaken which probes the meaning of these various data. Trends in these findings point to intra- and intersegmental energy transfer, center of mass excursion, and elastic energy storage as potential areas for expanding our understanding of the biomechanics of economical movement. These possibilities might be explored by enhancing link-segmental mathematical models to predict what makes movements economical and then testing these predictions by using biofeedback techniques to train subjects to perform the correct movements while being monitored. Optimization models might offer an additional strategy for developing a theory of mechanically and energetically economical movement.