Use a weighted club to feel core-driven backswing
The coach uses a heavy training club so you can feel whether your backswing is driven by your body or your arms. At checkpoints like the set position and the top, hold the club stable and notice which muscles are working; if the club feels heavy in your arms, you've taken it back with your arms and hands rather than supporting it with your core.
Channel: PorzakGolf
Watch official source at 0:51Why this context matters
Uses a weighted training club as a feedback tool for the takeaway.