Rory McIlroy Shares How He Uses The Ground For Power
The guys at Me and My Golf kicked off 2018 on a high note with this video featuring Rory McIlory. In addition to being one of the most prodigious drivers in golf, Rory is one the most candid and thoughtful interviews in sports. His approach to golf reflects a deep understanding of technology and steadfast appreciation of feel. In many ways, Rory is a model of the modern professional golfer.
At the 3:30 mark Rory begins hitting driver. It’s always a sight to behold, but especially fascinating to see him analyze his Trackman data with Andy and Piers.
An interesting data point that Andy and Piers noted immediately was Rory’s +5.6 attack angle. As we’ve covered in several pieces in the past, the ability to hit up on the ball is a key component of achieving optimal launch conditions with the driver. Players like Rory and Justin Thomas drive hard into the ground with their lead leg on the downswing which aides in speed production, but also helps orient their body to hit up on the ball.
The biggest hitters on the PGA TOUR will squat down 1″ – 2″ during the backswing and thrust their hips vertically 2″ – 5″ as they approach impact. As the player pushes into the ground and lifts their hips, it raises the handle of the club, shallowing the club head and helping them to increase their angle of attack. By achieving a higher attack angle, they are able to minimize spin and optimize launch conditions.
While facilitating a higher attack angle is a helpful bi-product, most obvious benefit of ground reaction force is speed. When Rory visited TPI in his early Titleist days, Dr. Greg Rose measured his hip speed at 720°/second, almost 200°/second faster than the PGA TOUR average. There are a lot of factors that contribute to Rory’s speed, but his ability to use to the ground is one of his foremost skills.
According to BODITRAK advisor Dr. Sasho MacKenzie, the golfers push into the ground to generate speed and also to control their body through the swing. Sasho explains how:
Faster clubhead speeds are associated with more force on the grip. For Rory, the force from the club goes from next to nothing to over 100 lbs in less than .25 seconds. The club is going to be pulling Rory towards the ball with over 100 lbs of force through impact. The squat into the lead side, at the start of the downswing, allows for a quicker rise in the GRF under the lead foot. The GRF will be surging up as Rory actively tries to reverse the squatting motion. These actions not only facilitate the generation of clubhead speed but also quickly generate momentum in his body, which is directed away from the force of the club through impact
Golfer’s push into the ground to generate speed, but also to put their body into a state that can manage the club’s momentum while maintaining balance through impact and into the finish.
At around the 7 min mark of the Me and My video, Rory starts talking about his keys to power. Specifically, how he uses the ground to generate speed.
The observations were so good that we transcribed Rory’s words and offered some commentary below.
A big thing for me is that I use the ground a lot. I use my legs a bit more than other guys do so I like to have a really stable base.
- Referring back to Sasho’s observation above, smaller players have higher ground reaction forces at the same swing speed in order to compensate for the force of the club.
“For a given clubhead speed, golfer’s with less mass – like Rory – will need more body motion up and left leading into impact to feel like they are in control and not the club,”
I try to keep the right leg very flexed, but still load into it. From there, there’s so much energy transfer to the left side.
- One of Rory’s hallmark moves is his squat as he begins his transition. Like Sam Snead and Tiger Woods, the squat sets Rory up to use the ground effectively to maximize speed at impact.
My first move on the way down is that shift onto the left side before anything happens [with my arms].
- This is another common trait among elite players. While Rory is likely referring to a lateral bump (shift in mass), we actually see pressure start to shift to the lead side before the backswing is completed. Many amateurs are late in shifting pressure which makes it difficult to sequence effectively on the downswing. In fact, one of the strongest relationship between clubhead speed and ground reaction force is seen when the shaft is perpendicular to the ground on the downswing (see graph on the right based on Sasho’s research at at St. Francis Xavier University). “You can’t wait for impact,” says Sasho. “By that time, it’s too late.”
I’m really bumping into that left side and pressure goes down my left leg. Just before impact, [my lead hip] goes up.
- Rory acknowledges a move that has become increasingly common in the modern game. The fastest swingers in golf often push into the ground so powerfully that it causes them to thrust (or jump), often resulting in an unweighting of one or even both feet. This is why we see Justin Thomas with only 7% of pressure on his lead leg at impact or why Bubba Watson is airborne.
Rory’s awareness of his ground mechanics is tremendous. It’s interesting that he clarifies with Andy and Piers that he doesn’t think about what his lower body is doing during the swing, but he clearly thinks about it during analysis and practice. Rory knows that the more he understands about using the ground the his benefit, the better his performance. Knowledge truly is power.