Human movement is a funny old thing. The complex structural connections throughout the body mean that movement is rarely isolated to a particular region. We tend to think that running is all about the legs – because that’s where we feel it. But the arms play an equally important role.
One of the fundamental mechanisms involved in efficient running is the counterrotation of trunk and hips. Forward propulsion is generated by driving the hip forwards (as we discussed in the first Tutorial in this series), but this can only happen (efficiently) if the opposite shoulder rotates backwards. And this is where arm swing comes in. Swinging the arm backwards sends the shoulder back and rotates the trunk which enables (and empowers) the opposite hip to drive forwards.
However, arm swing for distance running (sprinting is different) should not consume much energy – it should be relaxed and quite subtle. It should, perhaps counterintuitively, be a backswing rather than a forward swing.
And, what are you doing with your hands?
Learn more in this short video.