Arm swing
How your arms swing
Your arms go with your legs at every step. Runify Motion measures the average elbow angle as they swing, for the left arm and the right.
Descriptive measure: the app gives you the value and explains it, with no score and no verdict.
Flight: shoulder, elbow and wrist of both arms
How to read the value
180° is a straight arm; the lower the value, the more bent the elbow.
It’s a descriptive measure: the app gives you the value with no score. The elbow is the point pose models measure least well, and the arm far from the camera is often hidden by the trunk.
What it can mean
Swinging your arms helps balance the rotation of your trunk, but no elbow angle has been shown to be better than others: the value describes how you run.
Running with your arms held still takes more energy than letting them swing (Arellano and Kram 2014); between a bent arm and a straight one, a small study found no difference (Yegian 2019).
Studies: Arellano and Kram 2014; Yegian 2019.
To measure it well
Watch the video in slow motion: arm movement is easier to understand as a whole than from one angle.
What the app suggests
Nothing to try: the value describes how you run; it doesn’t judge it, and the app doesn’t make up exercises for the arms.