If we had to name one pattern behind more amateur slices, blocks, and fat shots than anything else, it's the trail arm. Amateurs lift it. Better players fold and lower it. Those are completely different motions that produce completely different swings.
A lot of the clearest work comparing amateur and tour trail-arm behavior comes from the 3D research published by Athletic Motion Golf, and it lines up with what we see on our own capture data.
Lifting vs. folding
Lifting is abduction — the trail elbow travels up and away from the ribcage, often ending high and behind the body. It raises the hands, steepens the shaft, and disconnects the arms from the torso's rotation.
Folding is flexion — the elbow bends while staying roughly in front of the torso and connected to the body's turn. The hands stay deeper, the shaft stays shallower, and the club is in a position the body can deliver.
How much bend do you actually need?
Roughly 90° of trail elbow flexion at the top is a solid working reference for a full swing — the classic "waiter's tray" look, though more supported and less overtly under the shaft than that cue suggests.
- Too little bend (a straight, stiff trail arm) forces the arms to lift to reach the top and leaves the swing dependent on timing.
- Too much bend collapses the swing radius, kills width, and usually pulls the club inside and behind.
The bend also has to happen at the right time. Trail elbow that stays nearly straight to P2 and then folds is the pattern; folding early is what drags the clubhead inside the hands.
The part almost nobody trains: lowering in the downswing
The trail arm's most important job happens in transition. As the lower body starts down, the trail elbow drops back down in front of the torso — closer to the trail hip — while the elbow stays bent. That's the shallowing move. It's not a hand or wrist action.
Amateurs skip it. The elbow stays high and behind, the shaft steepens, and the only ways out are coming over the top or flipping. This is why "shallow the club" instructions rarely work as a wrist cue: the shaft shallows because the trail arm lowered.
A useful checkpoint: at P6 (lead arm parallel in the downswing), the trail elbow should be in front of the trail hip and still carrying bend. The arm straightens through impact — it isn't straightened to get there.
Drills
1. Towel under the trail arm
Classic connection drill. Hold a towel lightly under the trail armpit for half swings. If the arm lifts, the towel drops. Half swings only — full swings need some separation.
2. Pump-to-P6
Go to the top, then pump down twice with one intent: get the trail elbow in front of the trail hip while it stays bent. Hit on the third.
3. Trail-arm-only wedges
Half wedge shots with the trail arm alone. There's no way to hit them decently while lifting — the arm has to fold and lower. Best isolation drill available.
Check it on video, then measure it
Down-the-line video shows lifting immediately. To see the lowering motion clearly — how much, how fast, and whether the lower body created the room for it — you want 3D. We capture this in the studio with Swing Catalyst.
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