So keeping my elbow still is OK, but misnaming the muscles used hurts me?
pj
chgo
Naming any single muscle hurts you.
Probably the biggest drawback of a great mechanical idea like a fixed elbow is that by hardcore adhering to it, players lock themselves out of the possibility for an effortless reliable stroke and just hone in on relying solely on elbow flexors.
If they let their arm work as it does in every other athletic endeavor, some slight elbow movement is very likely to creep in, at least in the backswing, if not the actual forward stroke.
Luckily, not every pendulum stroke instructor is so strictly tied to the idea of a fixed elbow that they won't allow for a touch of movement in warmup strokes/backswing.