FINIS Hydro Hip The hip blades create resistance during rotation, which builds core muscles for a more powerful stroke. Improves stroke timing by forcing hip rotation at the top of each stroke. Provides instant stroke feedback  If stroke timing is incorrect the swimmer's arm will hit the hip blades. Best used during drill sets or short distances. Improves backstroke and freestyle hip rotation, and can be placed toward the chest for breaststroke to prevent dropped elbows and develop a more efficient arm stroke.