1) Four speakers presented modern perspectives on the Six Determinants of Gait originally proposed in 1953, finding that some determinants have been disproven or require refinement based on new evidence. 2) One speaker found that flattening the vertical movement of the center of mass during walking does not reduce metabolic energy costs as originally thought. 3) Another speaker found preliminary data supports replacing two disproven determinants with equations relating peak vertical movement and acceleration to walking speed. 4) A third speaker found that heel rise at the end of stance can account for the reduction in vertical center of mass displacement during walking. 5) The last speaker proposed a mechanistic approach finding that redirecting the center of