By Coach Adolfo Salgueiro
Last week I wrote about the first aspect of arm swing biomechanics, which is pushing your elbows back. If you haven’t read that one yet, I invite you to do so by clicking here, before returning to this post. You will find the link back to this one at the end of that post.

US runners usually keep their arms in a 90-100 degree angle and do not cross their bodies as they swing. East Africans use a different technique. This is US Marathon record holder, Ryan Hall.
Pushing backwards is just the first part of the equation and by no means its only part. Many pieces need to be coordinated so the best biomechanical and energy-saving results can be reaped. As with everything else in our sport, it starts with a good posture. There is nothing to gain when you have a beautiful arm swing motion if you are not running upright, leaning forward at the correct angle, and not bending from your waist.
When it comes to arm swing, there are many components that need to work in a coordinated fashion. It must be a seamless symphony of motion between the upper and lower body. One where the arms will complement and enhance what is happening with your legs and feet.
Check what Coach Steve Magness has to say on this subject in his book The Science of Running: “it goes beyond just the arms and legs working in opposition; when they both stop, forward and backward motion is also coordinated. When the arm stops moving forward and is about to reverse direction the opposite leg should reach its maximum knee height before starting its downward movement. Similarly, when the arm reaches its maximum backward movement before switching directions and coming forward, the opposite leg and hip should be at their maximum extension backwards”.
Arms should be relaxed and that starts at the fingertips. When you tighten them in a fist, the rest of the muscles follow the trend upward until you reach the shoulders. This refrains the free flow of the arm swing. The best way to relax that kinetic chain is with the “potato chip technique”.
Pretend you are holding a potato chip between your thumb and index fingers. They are very fragile and will break if you press too hard. As you do this, the remaining three fingers will be forced to relax and easily positioned below the potato chip. This relaxation on your hands will start creeping upwards and relaxing your arms, as long as you are positioned properly. Avoid having your wrists parallel with the road, as it will make the relaxed wrists sag down. They should be perpendicular to the road.

East African runners hold their hands closer to the heart and cross their bodies as they swing. US runners have a different technique. This is Tirunesh Dibaba, from Ethiopia, winner of the 2017 Chicago Marathon, who also has two seconds in London.
Regardless of your arm swing technique, the movement begins at the shoulder, like a pendulum and not from the elbows. From there down, what I like to teach my athletes is to have forearms below the elbow at an angle from 90-100 degrees, with the relaxed hands at the end. As you push back your elbows, the relaxed knuckles should reach the hip, before changing directions. As you began to run faster or sprint, they will automatically start reaching further back.
In his book Run for Your Life, Dr. Mark Cucuzzella goes through his Five Principles of Running. Number 3 is “Use your arms and hands to set your rhythm”. The key here is that when you swing your arms from your shoulders using the strong lower trapezius muscles “your knuckles stay close to your sternum but should not cross your center line”.
As in everything, there is no one-size-fits-all technique when it comes to arm swinging. Elite East African athletes run with their arms tucked closer to their bodies, in an acute angle (about 45 degrees) and with their hands very close to their hearts. They also cross their torsos on the swing. In the US we carry our arms lower and we don’t cross. Regardless of what style you use, they both have relaxed arms, and they both push elbows back.
I tried this East African arm-swing style for myself and I did feel a change in my stride. It became shorter and started falling closer to my center of gravity. But it was exceedingly difficult to keep my arms relaxed in that position and it required extra effort to push my elbows back. My arms became automatically tense. But it works for Eliud Kipchoge and his running buddies, so we can’t discount it.
As for the many benefits of the proper arm swing technique, Dr. Cucuzzella adds that the arm swing will help also in providing stability, counterbalancing the movement of the opposite leg, balancing the pelvis, and helping maintain forward momentum. This alone should be enough for any runner to start paying attention to their arm swing technique, right away.
Please understand this is not a comprehensive research paper on arm swing. There are entire books and studies on this subject. It is just a review on the basics biomechanics and technique so you can understand how important this is in your running form. If you start being aware of your arm swing, you can make your running way more efficient.
Very interesting and useful.
As a someone who is not a runner, if I start to run thinking about a potato chip between my fingers, I will feel hungry 😂
Very good
Thanks again Adolfo. As I stated in your previous blog. I had to really learn this, I’ve gotten better, more conscious. My coach told me about the potato chips… I try to remember as much as I can, not to cling closing my hands.
Very useful information Coach Adolfo. I have been using the "potato chip" technique to help me get rid of my bad habit of tightening up my shoulders…. Thank you!
Keep working at it. It doesn’t happen on the first try. You need to keep thinking of it until it becomes second-nature.