common forms of a non-mechanical release are split-finger and three-under. Split-finger aiming requires the archer to place the index finger above the nocked arrow, while the middle and ring fingers are both placed below. Three-under aiming places the index, middle, and ring fingers under the nocked arrow. This technique allows the archer to better look down the arrow since the back of the arrow is closer to the dominant eye, and is commonly called "gun barreling" (referring to common aiming techniques used with firearms). When using short bows or shooting from horseback, it is difficult to use the sight picture. The archer may look at the target, but without including the weapon in the field of accurate view. Aiming then involves hand-eye coordination—which includes proprioception and motor-muscle memory, similar to that used when throwing a ball. With sufficient practice, such archers can normally achieve good practical accuracy for hunting or for war. Aiming without a sight picture may allow more rapid shooting, not however increasing accuracy. Instinctive shooting is a style of shooting that includes the barebow aiming method that relies heavily upon the subconscious mind, proprioception, and motor/muscle memory to make aiming adjustments; the term used to refer to a general category of archers who did not use a mechanical or fixed sight. Physics When a projectile is thrown by hand, the speed of the projectile is determined by the kinetic energy imparted by the thrower's muscles performing work. However, the energy must be imparted over a limited distance (determined by arm length) and therefore (because the projectile is accelerating) over a limited time, so the limiting factor is not work but rather power, which determines how much energy can be added in the limited time available. Power generated by muscles, however, is limited by force–velocity relationship, and even at the optimal contraction speed for power production, total work by the muscle is less than half of what it would be if the muscle contracted over the same distance at slow speeds, resulting in less than 1/4 the projectile launch velocity possible without the limitations of the force–velocity relationship. When a bow is used, the muscles are able to perform work much more slowly, resulting in greater force and greater work done. This work is stored in the bow as elastic potential energy, and when the bowstring is released, this stored energy is imparted to the arrow much more