May’s Pro Tip of the Month: Trail Arm Action: Explaining Why Swings Look So Different

There must be some reason swings can look so different but be equally effective. It’s not that these players woke up one day and decided to swing in such a fashion that is less than orthodox in appearance. More than any other anatomical feature, in my opinion the one that contributes most to the “look” of a golf swing is a player’s Trail Arm Action. This is defined as the way your Trail Arm (right arm for a right-handed player) is facing coming into impact and also relates to various other “looks” in the swing.

Even one who has never seen a golf shot played would look at Adam Scott’s swing and correctly assume that he is an expert player with great ball striking ability. Less people would assume, upon inspecting visibly, that Raymond Floyd was every bit the ball striker or that Matthew Wolff would become one of the best players in the world for a time, almost winning the US Open. There must be some reason swings can look so different but be equally effective. It’s not that these players woke up one day and decided to swing in such a fashion that is less than orthodox in appearance. More than any other anatomical feature, in my opinion the one that contributes most to the “look” of a golf swing is a player’s Trail Arm Action. This is defined as the way your Trail Arm (right arm for a right-handed player) is facing coming into impact and also relates to various other “looks” in the swing.

Let’s first define the spectrum of Trail Arm alignments:

Zach Johnson: Notice the trail forearm facing upward and the extension post-impact.
Zach Johnson: Notice the trail forearm facing upward and the extension post-impact.

“Under” Alignment:

A player whose trail forearm faces up toward the sky coming into impact would be an example of an “Under” golfer. These golfers tend to have strong grips, wide backswings, and appear to be extending toward the target post-impact while their trail shoulder stays pointing at the ground well after the ball is struck. Zach Johnson, Dustin Johnson, and Gary Woodland would be great examples among the best players in the world. Our club has several very good Under players including Jason Reich and Mitch Harrison. It is common for Under golfers to play draws as their trail hand grip tends to move to the strong side but that is not necessarily the case as Gary Woodland has been an effective fader of the ball for over a decade.

Patrick Cantlay: Notice how his shoulders become more level sooner and there is the appearance of him standing up while he is pushing down with less extension post-impact.
Patrick Cantlay: Notice how his shoulders become more level sooner and there is the appearance of him standing up while he is pushing down with less extension post-impact.

On-Top/Cover Alignment:

On the other end of the spectrum would be players whose forearms face down toward the ground to some degree. These are referred to as “On-Top” or “Cover” golfers. While Under players look to be “lifting something up,” an On-Top player appears to be “pushing down on something.” These golfers tend to have weaker grips, narrow backswings, appear to be getting taller earlier in the downswing, and post-impact will have very little extension toward the target. Perhaps a textbook example of an On-Top player is Matt Kuchar. I remember wondering how he could hit the ball as far as he does with such an odd-looking motion, the simple explanation being that he swings in a way that matches his biomechanics. While it is common for On-Top golfers to hit fades because their trail hand grips tend to move in the weaker direction, there are those that still play draw. For example, Rory McIlroy is on the On-Top side of the spectrum, albeit very slightly, and in his younger days played a pronounced draw.

Adam Scott: Notice how his swing is in a “middle ground” between Zach Johnson and Patrick Cantlay. The width of his swing matches on both sides of impact, his right shoulder is higher than Zach but lower than Patrick. He is as much in the middle of the spectrum as it gets.
Adam Scott: Notice how his swing is in a “middle ground” between Zach Johnson and Patrick Cantlay. The width of his swing matches on both sides of impact, his right shoulder is higher than Zach but lower than Patrick. He is as much in the middle of the spectrum as it gets.

“Side-On” Alignment:

In the middle of this spectrum would be “Side-On” golfers. The trail arm of these golfers moves as if they were pushing something sideways toward the target. Side-On players tend to have the swings we like to look at; this is because being the middle of this spectrum provides a lot of symmetry to the golf swing. The width of the backswing, downswing, and through-swings look in balance with each other as opposed to the wide-narrow-wide width management of Under golfers or the narrow-wide-narrow width management of On-Top golfers. Adam Scott, Louis Oosthuizen, and Tiger Woods are all very close to being perfectly side-on and, not surprisingly, their swings are all lauded as among the best of all-time.

Tiger is a great example of the dangers of moving away from one’s natural Trail Arm alignment. In 2000, while he was playing the best golf of his career, he was more or less perfectly Side-On. As his time with Hank Haney progressed, he moved more and more under with his arms getting too wide in the backswing and struggled hitting fairways. When he began working with Sean Foley in 2010, his swing moved more and more toward the On-Top width management and his back paid the price. For the record, this is not an indictment of Sean Foley as Tiger, no matter who his coach was at the time, always knew what “look” he was trying to achieve and had final say.

It should be said that there are not only three options. You can fit anywhere in this spectrum and play great golf. So, how do you discover where you fit in this spectrum from perfectly Under to perfectly On-Top? In other words, to what degree are you Under or On-Top? Here are the steps for screening yourself:

  1. Get into a golf posture
  2. Put your Trail Arm behind your back
  3. Let your Lead Arm swing across your chest as naturally as possible; in other words, don’t think golf!
  4. When your lead arm gets to parallel with the ground, clap your hands together
  5. Lastly, take away your lead arm and observe in what direction your trail palm is pointing
Under - Side-On - On-Top/Cover
Under – Side-On – On-Top/Cover

If your trail palm is perfectly straight up and down, you are most likely a Side-On golfer. If your trail palm is pointed at the ground, then you are a most likely an On-Top golfer. It your trail arm is facing the sky, then you are most likely an Under player.

To reiterate, you should observe to what degree your palm is facing anywhere other than Side-On. For example, my palm faces up to a small degree and would be classified as a “Side-Under” alignment. My twin brother, meanwhile, has a palm that faces slightly down and is classified as a “Side-Cover” player. My swing has more width in the backswing and more extension toward the target.

Interested in your own biomechanics. We can screen this in a lesson any time! Interested in these concepts in general? A Google or Youtube search of the names EA Tischler or Mike Adams will send you down an interesting rabbit hole that hopefully leads you toward owning and loving your own talent rather than pining for that of someone else! See you all at the course!

By: Ryan Williams, Player Development Professional

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