The Bolster paddles develop an early vertical forearm (EVF) position and increase stroke efficiency. An EVF position utilizes the entire forearm during the pull, creating uniform application of force from fingertips to elbow. This creates and sustains longer peak velocity through the power phase of the stroke pull.  At the same time it grooves neural pathways for stroke specific strength.  Correct stroke refinement is promoted through muscle memory of proper hand, wrist and forearm position. The Bolster paddles are a versatile tool for all four swim strokes.