One floor drill for three swing faults: thoracic rotation

Early extension, casting, and a fall-back finish frequently trace to one place: the thoracic spine, the segment of your back from the base of the neck to the bottom of the ribcage. The open book, a floor drill that takes 4 minutes, is the one we'd pick to work on it. First, a 60-second seated test tells you whether your mid-back is the bottleneck.

If you've taken three lessons in the last two years and heard "stop standing up out of the shot," "stop flipping at the ball," and "finish balanced," you may be solving one mobility problem three different ways.

Why one stiff segment produces three swing faults

In our coaching view, a full swing asks for something close to 90 degrees of shoulder turn against hips that turn far less, and the mid-back supplies most of that difference. The gap between shoulders and hips is what coaches call the X-factor. (More on that in why your X-factor stopped growing at 45.)

When the thoracic spine won't rotate, the body finds the turn somewhere else:

• Early extension. Your pelvis pushes toward the ball in the downswing to make room, because the torso can't rotate out of the way.
• Casting. The arms start the downswing to get the club moving, since the body has no coil to unwind.
• Fall-back finish. You can't rotate through to the target, so you stop the turn and lean back onto the trail foot.

Fix the segment, and all three tend to improve at once.

The 60-second test

This is TPI's seated trunk rotation screen, and you can run it alone.

1. Lay two golf clubs on the floor in a V, each one angled 45 degrees out from the point where you'll sit. The point of the V faces away from you.
2. Sit on the edge of a chair or bench at the point of the V, knees and feet together, feet against the clubs.
3. Hold a third club across your shoulders behind your neck, or cross your arms over your chest. Sit tall.
4. Without letting your knees or hips move, rotate your shoulders to the right as far as you can. Look down. If the club across your shoulders lines up with or passes the club on the floor, you've reached 45 degrees.
5. Repeat to the left.

TPI treats 45 degrees each way as the pass mark. If you can't get there on one or both sides, your thoracic spine is a bottleneck. Write down which side is worse and retest in 3 weeks.

The drill: open book on the floor

1. Lie on your side with your knees stacked and bent at 90 degrees, arms straight out in front of you, palms together.
2. Keep your knees glued together. That locks your hips out so the mid-back has to do the work.
3. Peel the top arm open like a book, following the hand with your eyes, until the back of your hand touches the floor behind you. If it doesn't reach, stop where it stops.
4. Breathe out as the arm opens. Hold 3 seconds at the end.
5. Bring it back slowly. That's 1 rep.

Do 10 reps each side, once a day. It takes about 4 minutes. If your knees drift apart, put a rolled towel between them and squeeze it.

Common mistakes: rushing the reps, letting the bottom knee lift off the floor, and rotating from the neck instead of the ribcage. If your head turns and your chest doesn't, you're getting nothing from it.

What the research says

• Torso and pelvis separation predicts ball speed. Myers and colleagues (Journal of Sports Sciences, 2008) measured 100 recreational golfers. The high ball velocity group averaged 59 degrees of separation at the top of the backswing, the low velocity group 44 degrees, with a correlation of about r = 0.55 between separation and ball velocity. Total shoulder turn on its own was not significantly related to speed.
• 45 degrees is the screening pass mark. TPI's seated trunk rotation test, which its certified coaches run on tour players and amateurs, uses 45 degrees each way as the threshold. It's a screen, not a proven performance minimum.
• A daily golf-specific routine adds speed. Fradkin, Sherman and Finch (British Journal of Sports Medicine, 2004) had 10 golfers do a short warm-up 5 times a week for 5 weeks. Their clubhead speed rose 24 percent from their own week-1 baseline, and about half of that gain showed up immediately from warming up at all. A matched control group of 10 barely changed. It's a small study and the gain is large compared with later warm-up trials, so treat the number as a signal, not a promise.

What to do tomorrow

Run the seated test tonight and write down which side is worse. Then do the open book for 10 reps a side every morning for 3 weeks. If you're playing this weekend, do it in the parking lot too, as the mobility piece of a proper cold-morning warm-up.

If you'd rather have this decided for you, FitCaddie's Less Pain & Mobility program builds thoracic work into 5 to 10 minutes a day and swaps anything that bugs a sore back.

Sources

• Myers J, Lephart S, Tsai Y-S, Sell T, Smoliga J, Jolly J. The role of upper torso and pelvis rotation in driving performance during the golf swing. Journal of Sports Sciences. 2008;26(2):181-188. doi:10.1080/02640410701373543
• Titleist Performance Institute. The Seated Trunk Rotation Test: Screening Mobility.
• Fradkin AJ, Sherman CA, Finch CF. Improving golf performance with a warm up conditioning programme. British Journal of Sports Medicine. 2004;38(6):762-765. doi:10.1136/bjsm.2003.009399