There was a test shown by Joey Myers of Catapult loading system, The test was standing with the shoulders square and trying to lift a 45 pnd weight straight forward, shoulder raise. The weight is heavy for that type of lift. Then he took a step with the opposite leg and lifted the weight with much less effort.
So he introduced momentum to the lift and made the lift easy. How much does this apply to no stride vs stride in swinging a bat/implement?