In the case of the BowTech Patriot and Mathews Q2, Q2XL, and Legacy among others, the vertical force technology used works virtually the same way. With very little limb movement, the way the force is generated is by pre-stressing the limb (putting more pressure on the limb while it is "at rest"
. In this type of technology, you will typically see shorter stiffer limbs, which don't take as much bend to put the proper amount of pre-stress on them. The pre-stress in the limb helps it store more energy when it is flexed during the draw cycle, thus providing more energy to the arrow with less movement of the limb. Hope this helps.
MN_BOWHUNTER