Run long enough and the sport shapes us. Running moulds the human form in ways both beautiful (on which I’m still waiting) and grotesque. A runners legs get all the attention, the upper body gets little consideration. But how we hold our arms affects how we run probably in ways we don’t expect. This is because arm swing is a critical part of stabilizing the body while running. The arm swing can tell us a lot about what is happening below. Sometimes, the key to fixing lower body aches, pains, and inefficiencies may very well lie in addressing the arms. Weakness, stiffness, fatigue, or pain can cause inefficiencies in the running pattern. Arm and leg movement is “neurocoupled” allowing coordinated rhythmic movement during running (Sylos-Labini et al., 2014). Because of the reciprocal arm-leg connection, a faulty arm swing will often occur as a result of a leg issue – and may appear even before leg pain or injury occurs. For distance runners, improving the efficiency of the arm swing can improve speed, efficiency and even prevent lower extremity injuries.
Running is all about creating a comfortable rhythm. An easy way to see just how important your arm swing is and how it can affect your overall rhythm is to run with your arms relaxed down by your sides. Not only will this feel extremely uncomfortable, but you’ll also notice the additional work it places on your back, hips and legs. The integration of the arms and legs is crucial but poorly understood. Rodger Kram Chris Arellano investigated the enduringly confusing topic of what we do with our arms while running, and why. The study compared four different arm positions in running postures: “normal,” holding the hands behind the back, holding the arms across the chest, and holding the hands on top of the head. running with a normal arm swing did indeed burn less energy (3% less than the behind-the-back form, 9% less than across-the-chest, and 13% less than hands-on-head). It also significantly reduced shoulder and pelvis rotation (Arellano & Kram, 2014). While most runners concentrate on leg stride to improve overall efficiency and waste less energy, the arm swing is commonly neglected. But proper arm swing reduces overall energy expenditure, propels the body forward and improves overall running pattern by helping to lift the body off the ground with each stride and balances the body as it moves. This helps improve pelvic rotation, relieving stress from the lower body and making things easier on the legs.
A lot of times when we see something strange happening with the leg during running we immediately work on fixing the problem by adjusting how that particular leg is working. For example, if a runner extends out with the lower leg, we immediately try and correct them and prevent them from over striding by having them put their foot down sooner. Instead, the problem seen with the leg could simply be the symptom. The arms and legs are timed so they work perfectly in synch. If the runner has a problem with their arm swing that causes a delay in the typical forward and backward motion, then the opposite leg must compensate for this delay. In many cases, the opposite leg extends outwards as a form of compensation. Therefore, it is important to look at the whole body and understand that this might simply be a form of compensation. So that lower leg niggle that’s been plaguing your training may in fact be a problem in your upper body, that is affecting your arm swing. And your next personal best may be an “arms race” rather than be in your legs.
Arellano CJ & Kram R. (2014). The metabolic cost of human running: is swinging the arms worth it? The Journal of Experimental Biology 217, 2456.
Sylos-Labini F, Ivanenko YP, Maclellan MJ, Cappellini G, Poppele RE & Lacquaniti F. (2014). Locomotor-like leg movements evoked by rhythmic arm movements in humans. PLoS One 9, e90775.