How A Rotary Stool Became Our Favorite Tool for Helping Golfers Use the Ground

If you’re wondering why your favorite professional golfers and podcasters are spinning around on rotary chairs, we might be able to help you with an explanation.

Golf coaches are infamous for turning household items into teaching tools, and it turns out we're no exception as a rotary stool has become one of the most effective tools for communicating how a golfer should push against the ground.

Whether early extension, loss of posture, sway, slide or even coming over the top, many of the most common swing characteristics we identify can be addressed by improving how we use the ground. 

As with every positive outcome at our facility, our understanding of how to help golfers use the ground more effectively started with an assessment. 

Whenever a golfer comes to TPI (or sees a TPI Certified at their facility), we always start with an assessment.  Essentially, we want to know how a golfer is capable of moving (through our physical screen and power testing) and how they move in their swing (through analysis of 3D and force data).

While we've identified deficiencies in movement for decades through our screens (such as limitations in mobility, stability or motor control), we've recently started to notice common inefficiences in how golfers interact with the ground from the force plate data we've been gathering for the last five years.   

One thing that's become clear is HOW (timing and direction) we teach a golfer to push against the ground can be just as important as HOW HARD they are pushing. 

Want to teach a golfer to improve HOW they push?  Have them develop the feel on a rotary stool.  Watch our lesson with Mike from Chasing Scratch below:

So why does this work?   

Most coaches or golfers with a passing interest in biomechanics are familiar with the subject of ground reaction forces.  At TPI, the relationship between ground forces and club head speed is a concept we’ve discussed for over a decade.  We dedicate a significant portion of our advanced Golf and Power courses to studying how to help golfers push against the ground to maximize speed and efficiency.    

When considering ground reaction forces, the tendency is to focus on how a golfer pushes down against the ground (vertical force), but it’s just one of the three forces and three torques that we analyze in our advanced Golf and Power courses.

One of the key kinetic variables we evaluate in any force analysis is anterior-posterior force (or heel-toe force).  Not only is this a meaningful contributor to clubhead speed, it can also help a golfer maintain dynamic posture and cover the ball at impact. 

So what is AP force?  This explanation of AP force from Mark Blackburn is as clear and concise as you'll find.  Not only is he one of the best golf coaches in the world, he's one of the best educators.  


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Golfers who don’t create sufficient AP force on the lead side commonly early extend. When a golfer uses their lower body to rotate their pelvis, the trail leg pulls them towards the target line and lead leg pushes them away from the target line.  This is what creates the torque which produces rotation. Most elite players generate twice the AP force away with their lead leg as they do with their trail leg.

You don't need a force plate to recognize AP force in the mechanics of some of the most talented and powerful golfers in the world.

Have you ever marveled at Scottie Scheffler’s footwork?  Notice how Scottie’s lead foot moves AWAY from the target line on the downswing?  That’s evidence of how much vertical and AP force he’s created.   It might not be what Scottie thinks about in his downswing, but it’s a result of how aggressively he pushes against the ground.  Recall Newton's third law: Equal and opposite.

Scottie might be an extreme example, but watch the lead foot of budding star, Ludvig Aberg.

Because speed is highly associated with greater ground reaction forces, the lead foot moving away from the target line is common in big hitters.  Watch where Gordon Sargent's (high-180's ball speed) lead foot starts vs where it ends up: 

Creating more force with the lead leg earlier in the downswing is something Mark has been working on with Charley Hoffman.  Charley stopped by during the lunch break at a Golf Level 3 seminar and let attendees sit in on his lesson (he's one of the most comfortable and accessible professional golfers you’ll ever meet). 

Here’s a drill Mark uses to create feedback with golfers, encouraging them to create that "frictional" force with their lead leg. 

By pushing against Charley's calf towards the target line, he's forcing Charley to push harder with the lead leg (more AP force).  This is an example of Reactive Neuromuscular Training. 

At the same seminar, one of our attendees, Charlie Udom of Sparc Golf in Portland, shared his immediate progress after working on this at the range one evening after the seminar was over.  Look at the before and after.

This is a lesson that Charlie brought back to his students, including his 14-year old niece and budding star, Melinee Udom.  Despite picking up golf three years ago, she's one of the most talented juniors in Oregon and already one of the fastest 14 year-olds you'll ever see.  She's strong (weight trains), athletic (gymnastics background) and pushes against the ground effectively.  Watch where her lead foot starts vs where it ends up.  AP force.


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As with virtually every swing tip, nuance and application are key to effectiveness.  When we encourage golfers to "use the ground for power" it's not just about HOW HARD they push, but HOW they push.

When we started studying ground interaction of the best players in the world over a decade ago, it's safe to say we never imagined a rotary stool would be a key teaching tool or that we'd see pro golfers getting reps in during doctor visits. 

If you are coach interested in learning more about how to help golfers through a deeper understanding of biomechanics, kinematics and kinetics, check out our advanced Golf and Power courses.

If you're a golfer interested in applying these concepts to your swing, check out our Find an Expert page



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