When walking, running or jumping in QM, the efficiency of movement depends first on the general posture of the four limbs, then on the coordination of the limbs in motion and their contact with the ground, and last on the smoothness, power and amplitude of the arm stride.
A balanced posture with the feet and hands under the hips and shoulders is best at rest, with the limbs going in "point" (feet/hands equally spaced around the upper joint) during motion. The relative height of the hip and shoulder is directly related to the achievable QM speed. Many running quadrupeds have an almost balanced limb length with slightly longer hind legs. In that regard, we are more closely related to smaller quadrumane monkeys (e.g. Capuchin monkeys) than to great apes which have longer arms and much shorter legs, and have limited QM speed.
Like the foot, the hand can strike the ground in different ways. Like for the foot, striking directly with the heel of the hand at the wrist propagates shock through the arm, while striking with the ball of the hand with some stabilizing help from the fingers enables to better absorb any downward momentum. In slow QM walk, it is not much of an issue, but it becomes fundamental to achieving good speed and fluidity in running and jumping. The hands and feet shouldn't cross or even touch during movement, except maybe for long QM jumps. The balance of speed and amplitude in classical running stride applies identically to the arms in QM: longer stride and then faster movement.