15 apr 2026
arm swing illusion
Came across an interesting idea in golf: the arm swing is an illusion. The arms look like they do the work, but they mostly go along for the ride. The body turns, the weight shifts, and the arms follow. What we see as an "arm swing" is rotation seen from the outside.
The biomechanics are what got me. A 3D rotation, seen from the front, looks like a 2D arm swing. It's an optical illusion. Worth a watch.