Increases blood flow to your muscles and neurologically prepares your body for high-speed, high-force movements. * Warms up the arm and shoulders, reducing the chance of chronic injuries when working with more intensive efforts. * Works with the natural flexibility of your shoulder, enabling to train your arm and shoulders by moving them in any number of directions, replicating the shoulder movements of your own sport. * Snap hook allows you to attach one end of the cord to a stationary object, such as a fence, tree, or pole, making this a very portable device.