Arm swing symmetry

How evenly your left and right arms swing through the running gait cycle.

Why it matters

Asymmetric arm swing is rarely a problem in itself — it's usually a visible symptom of a deeper mobility restriction in the thoracic spine or hip flexors.

What it means

Asymmetric arm swing is usually a downstream marker of thoracic stiffness or hip flexor tightness. A symmetry score above 90 is excellent; below 70 warrants mobility work. Because the arms and legs are cross-linked through the trunk, fixing arm swing rarely means focusing on the arms — thoracic rotation drills and hip mobility work are usually the more direct route.