Sprenger HS System 4 StirrupsThe advantages of the Sprenger Jointed Stirrups System 4 include: Pivoting into 4 directions simultaneously softens the impact on cartilage and ligaments Makes it easy to put the heels in the correct low position Superb strength and enchanced security Great comfort In 1998 Sprenger improved the stirrups flexibility by extending the joint with an additional link. The System 4 relieves hips, knees and ankles during riding and particularly spares