This article is a summary of a podcast I recorded with Dr. Sasho MacKenzie, regarded by many as the world’s leading golf biomechanics researcher. It is the most popular episode of the Fit For Golf podcast.
The main topic of discussion was how wrist angles in the golf swing influence club head speed. We also covered hand speed, whether golfers should train grip strength separately, and how overload and overspeed training can help.
The most important findings and our discussion are summarised below.
Listen to the full episode:
1. The Wrist Is The Joint Most Highly Correlated With Club Head Speed
“What happens at the wrist is certainly more highly correlated to clubhead speed than any other joint in the body.” When you look at how fast the hips, torso and arms are rotating, the correlations get higher the closer you get to the club.
“If I was gonna constrain a joint to limit your club head speed, that’s the one I would do.”
The wrist has two main movements. Radial and ulnar deviation, which most golfers would call hinging. And flexion and extension, which most golfers would call bowing and cupping. To keep it simple, we focused on the angle between the lead forearm and the shaft. This is what most golfers call lag.
A flatter swing, or a lower camera position, will make it look like there is more lag than there is. If you are checking your own lag on video, I’d recommend keeping your camera setup consistent.
2. Lag Had The Strongest Link To Ball Speed In The Biggest Study Of Its Kind
A study by Chu et al. (2010) measured 308 amateur golfers. They used full 3D motion capture and force plates, and the outcome measure was ball speed with driver.
They measured hundreds of variables at four points in the swing, including ground reaction forces, centre of pressure shift and X-Factor. Of all of them, the wrist hinge angle 40 milliseconds before impact, which is roughly when the shaft is parallel to the ground in the downswing, had the strongest association with ball speed.
Chu et al. (2010):
- Average ball speed of the golfers was about 140 mph
- Average wrist angle at 40 milliseconds before impact was 145 degrees
- For every 10 degrees more lag, ball speed went up by about 5 mph
The study didn’t report all 308 golfers, but using those numbers, a golfer with 170 mph ball speed would be around 90 degrees at that point. Golfers at 165 degrees, “those guys that kinda just drag the club through impact”, would be down around 130 mph.
I mentioned that so much of what we see online about club head speed is about ground reaction forces. None of that matters if the energy doesn’t get out to the club. “You can have the best ground reaction force pattern in the world, but if you don’t get that out to the club, it doesn’t really matter.”
3. Most Club Head Speed Comes From Forces Passing Through The Wrists, Not The Wrist Muscles
To create club head speed, work has to be done on the club. The wrist muscles are quite weak, and late in the swing the joints are rotating so fast that they can’t do much.
Most of the work is done by passive forces that pass through the wrist joints. These are created by the rest of the body, the legs, torso, lats, shoulders and pecs. “The wrist muscles can be thought of as putting the club into a position that allows those passive joint forces to do more work late.”
Take a 0.24 second downswing at 110 mph. Halfway into the downswing, only about a quarter of the club head speed has been generated. The other 75% is still to come, and the vast majority of it comes from those passive forces.
This is where the wrist muscles can hurt you. “The wrist muscles can actually mess things up for allowing those other body parts to get their energy out to the club.” If the angle is gone too early, there isn’t much you can do to get that energy out.
A pen and string explains it well. Tie a string to the end of a pen at a 90 degree angle and pull the string, and the pen rotates. Straighten it out to 180 degrees and pull, and the pen doesn’t rotate at all. The more wrist angle you have late in the downswing, the more potential you have to increase club head speed when you pull on the grip.
Among tour players, there is not much correlation between this wrist angle and club head speed. They are all already in a good range, and none of them are casting it from the top.
Free 10 Minute Follow Along Mobility Routine
Follow along with Mike through this free 10-minute mobility routine designed to improve range of motion between workouts.
4. Don’t Try To Hold The Angle
The obvious takeaway would be to hold onto the lag for as long as possible. Sasho was very clear on this. “I would say zero people are holding it. And I think that that’s terrible.”
In a simulation study he published in 2002 on delayed release in the golf swing, holding the wrist angle fractionally longer than it would naturally open only increased club head speed by 0.7%.
The problem is that the muscles holding the angle have to switch off and the muscles releasing it have to switch on. “You can’t instantaneously shut off your muscles.” That becomes a very awkward motion to make late in the swing, and close to impossible to do with any consistency. “So, yeah, definitely don’t hold the angle.”
Some tour players do manipulate the wrist angle at the very start of the downswing, like Jon Rahm and Brooke Henderson. But once the downswing starts, they are done trying to hold the angle with the wrist muscles.
5. Soften The Hands In Transition
So if you shouldn’t hold the angle, how do good players have so much of it late in the swing?
Golfers without enough lag have usually applied too much wrist torque at the start of the downswing. The wrist muscles fire too much too soon, and once that happens, there is no going back.
You can check this yourself on video. “I wanna see motion in the lower body before that club head changes direction.” If you film yourself face on and see the club popping up before there is much happening in the lower body, that’s probably not good.
When I watch really fast swingers in slow motion, it looks like they turn into the club before the club has moved at all. Then, when the arms start to swing down, you can see how much wrist angle is there.
“Trying to soften up those hands in transition is probably the most practical advice.”
This also links to slicing. Many golfers think leaving the club lagging will make it harder to square the face, so they try to get rid of the angle as early as possible. “I don’t think releasing it from the top is a great feeling for a lot of those high handicappers.”
6. Wrist Mobility Can Be A Limitation
I asked Sasho if a lack of lag is usually a physical limitation in the wrist or a technique issue. His answer was “maybe 50/50”, and that a lot of people could benefit from working on both.
Shane Lowry is a good example. From down the line, his trail hand almost comes off the grip. Sasho’s guess is that Shane has a mobility limitation in the trail wrist, and has found a way to let the club get into the position it needs to be in. Most amateurs keep the trail hand on the club, and lose a lot of lag because the wrist can’t get into position.
Wrist mobility can change a lot. Sasho saw people’s wrist mobility change hugely over three or four years when he played volleyball at university.
I’ve started prescribing small amounts of direct wrist and forearm training in some of my programmes. Something like two sets of 8 to 10 reps of weighted flexion and extension, radial and ulnar deviation, or pronation and supination. Taking a load through as big a range of motion as possible is really good for wrist mobility, and can help strengthen the wrists and elbows. Golfer’s and tennis elbow are popping up a lot more since so many golfers started speed training.
7. Grip Strength Is Best Trained With Big Lifts
Golfers often ask whether they should train grip, wrist and forearm strength separately. “Improving that is gonna be probably best done by just doing lifts, heavy repetitions of lifts that aren’t directly targeting the wrist joints.”
Three months of improving your deadlift, dips and pull-ups is likely to transfer more to the golf swing than isolated forearm work. Sasho was clear this is his gut feeling and theory, not something there is research on.
The most transfer comes from heavy speed training. Swinging 300 grams on the Stack helps Sasho feel comfortable letting his wrists be passive in transition. “That feeling of being comfortable allowing my wrist to be passive in transition is really helped by swinging heavier stuff.”
Swinging very light implements does the opposite for him. It feels like the driver is owning him, and he is more likely to cast.
My view is that if your grip, wrists and forearms are already getting heavy stimulation from deadlifts, rows, pull-ups and presses, you also need to factor in the load they get from overload and overspeed training.
8. Train Heavy And Light
Heavy and light implements train different parts of the swing.
Heavy implements help keep the lag at the start of the downswing and stop the wrists popping out early.
Light implements give you the confidence to release the angle really late, to the point where your hand can almost come off the club. When Sasho does one arm swings with a light implement and focuses on increasing his lag, he sees a 10 mph jump.
But the light work is a moot point if the lag has already been lost in transition. That’s why the heavy work matters.
9. Hand Speed Isn’t What Most People Think
Hand speed is the linear speed of a point on the grip, about 10 centimetres down from the butt of the club.
Peak hand speed is well correlated with club head speed, around 0.7 to 0.85 depending on the group. The timing of the peak is not. Hand speed peaks quite early, about halfway between shaft vertical and shaft parallel in the downswing.
Peak hand speeds for some long hitters: Cameron Champ and Wilco Nienaber were around 29 mph, Brandon Hagy 26 mph, Jason Day 23 mph, and Marty Jertson 23.4 mph (Marty is co creator of The Stack and plays to an extremely high level as a part time playing professional).
At impact, Champ’s hand speed dropped to around 9 mph and Nienaber’s to 10. Marty’s dropped to 2 mph, with a club head speed of 124 mph. That’s a good thing. Marty is getting more of the speed he generates with his body out to the club. This also means his driver speed scales up more relative to his 7 iron.
The problem with trying to maximise hand speed is Newton’s third law. To do work on the club you have to apply force to it, and the club applies that force back on your hands, which slows them down. “The faster I can get my hands going means I need to apply less force to the club, which means I’m doing less work on the club.”
Telling people to maximise their hand speed is “actually a great way to create so much lag that you can never get it out.”
Where To Find Sasho
You can find Sasho on X (Twitter), and find out more about the Stack System at thestacksystem.com and on the Stack’s Instagram.
Listen to the full episode:
