A removable, adjustable, foot-supporting and foot-positioning, orthopedic insert (40) for selectivley and correctly supporting and positioning the bottom regions of the foot, which is constructed to have an arch region (44) with a slit (41) and opening (48) in the upper surface and supporting or strengthenhancing ribbing structures (60-62) and support posts (50-54) with cylindrical pegs (55-59), respectively in the bottom surface. The insert (40) is designed for use in athletic or sports footwear (10), whereby the foot is selectively and correctly supported and positioned in the footwear (10), and the leg, in turn, is selectivley and correctly supported and positioned relative to the footwear (10).