Guiding the arms to move from the side position and to swing forward and rearward would provide an added benefit.  This pendulum motion of the arms in a forward and rearward rotation perpetuates a smooth fluid bio-mechanical movement. This is most desirable because it eliminates the conflicting negative side forces of crossover that would need to be overcome to continue moving forward.

Better yet, would be to bend the arms at the elbows into a 90 degree angle and allowing the hands to hang loosely thereby relaxing the arms as much as possible.  The arms are carried by the shoulders, upper body and neck muscles.  This position would enhance the benefit of the pendulum motion. The proper rotation of the feet is  heel to toe.  This means you place your foot out in such a position that your heel contacts the ground first.  Then roll forward onto your toe and lift your foot again.  This movement is preferred for it‘s fluid follow-through benefits.  It also minimizes and diffuses some of the physical trauma transferred from the feet and leg muscles that would occur if the foot would strike the ground flatly.