>>13447044In order to be accurate, an arrow must have the correct stiffness, or "dynamic spine", to flex out of the way of the bow and return to the correct path as it leaves the bow. Incorrect dynamic spine results in unpredictable contact between the arrow and the bow, therefore unpredictable forces on the arrow as it leaves the bow, and therefore reduced accuracy. Additionally, if an archer shoots several arrows with different dynamic spines, as they clear the bow they will be deflected on launch by different amounts and so will strike in different places. Competition archers therefore strive not only for arrows that have a spine within a suitable range for their bow, but also for highly consistent spine within sets of arrows. This is done using a static spine tester.
