1 The science of hand forces in Golf

Do you know what your hands are really doing during the golf swing?

Golf launch monitors measure almost everything about the golf ball flight. Video analysis reveals your body movement during the swing.

But the golfer’s only connection to the club-your hands- has remained largely invisible.

This guide explains why hand and finger forces may be one of the missing links in golf performance training.

In this guide you will discover, how they influence release, clubface control, consistency in swing and putting and why only an objective measurement is opening a new chapter in coaching and player development.

Why golf grip pressure matters more than most golfers think

Many golfers have heard the same advice from their coaches:

“Relax your grip”
“You hold your club to tightly”
“Use less force in your right hand”
“Let the club release naturally”
“Release through the ball”
“Keep your hands quiet”

They sound totally simple, yet they are difficult to apply consistently. The reason is also simple. Almost every piece of traditional coaching tells you what to do-but very little explains what you hands are actually doing during the golf swing.

How tight is too tight?
How much pressure should each hand apply?
Should your grip stay constant throughout the swing, or does it change?
And if you change, how do you change?
What role do your fingers play during the release?

Can hand forces actually be measured?

Until recently, the answer was largely no.

Every movement of the club begins with hand forces and finger forces on the grip. With this, you control release timing, clubface and finally consistency of your swings and your ball flights, the result of the whole exercise.

Golf launch monitors measure ball speed, launch angle, spin rate and so on with very high accuracy.

Video analysis helped to understand and analyse your body movements at millisecond time frame through swing progression. But neither system tells you how your hands create those results!

The golfer’s hands.

The hands are the golfer’s only physical connection to the club. All forces, all movements are transmitted by the hands to the club.

Every shot-whether it’s an extreme long drive or a delicate chip or putting. Everything depends on how the hands interact with the club.

If that interaction changes, then also the club path, the clubface orientation changes. And consequently, the ballflight changes.

It is a simple chain of events, but until now, one of its most important links has been largely invisible. Imagine a golfer who repeatedly pulls the ball left.

A launch monitor might tell you the clubface was closed at impact. Video may show you an early release (however you do you define that exact point…??). But neither explain why the clubface closed. Was trail-hand dominating? Force increases too early? Did the player release the club differently than on a previous swing?

Those answers remain largely invisible.

The difference between feel and reality

A big challenge in golf is that, we think we know what our hands are doing, because we feel it. However, our feel is often very different from reality! While one golfer may believe he is swinging very smoothly, the video may reveal rushed transitions.

Many golfers think they maintain a constant grip throughout the swing-however this is not reality!

Hand force patterns are highly dynamic.

Hand forces change continuously from address to take away, through backswing, transition and especially downswing and impact, follow-through.

Part of these forces and pressure shifts are dictated by physics (especially downswing-impact-follow-through).

During the downswing you transfer the of movement energy of your arm over to your club, especially to your clubhead. At release the clubhead is taking over and determines forces and movements. At release your hand slows down, but your club starts a rotational acceleration. The clubhead picks up speed through centrifugal force.

This force is coming from the rotation of the club and the clubhead speed, it’s not only a question of your personal biomechanics (like your arm length or muscle strength).

In contrast backswing is largely shaped by the golfer’s own movement pattern and techniques. This is how you prepare for downswing. This is a highly personal pattern and is largely determined by the way you have learnt golf years ago and also by your coach, of course.

Coaches rely on experience and on watching the golfer. Players rely on their feel.

Both are valuable, but neither provides objective data!

Why this matters for every golfer
Let us look at a situation every golfer has experienced

Consider two golfers which have very similar launch monitor data, for example:
Same clubhead speed
Same carry distance
Same launch angle

On paper you expect, that their swings will appear almost identical. If you check the video analysis you only see very slight differences in body movements.

But now ask them to do the same swing 20 or 30 time and then check the results. One golfer will deliver the same result with every swing.  The other golfer, will sometimes deliver the same result but sometimes too much to the left, or too much to the right, a slice, a hook and so on. The variability of the two golfers is totally different.

How can this happen?

Do you know the situation?

Have you ever experienced the same?

Normally you will start now investigating:

Is the club fitting okay?
Is it too hot?
Am I tired?
Is the training box not good?
Are the measurement correct?
Is the club too long? Is the club too flexible?

I’m sure you have experience with such an endless flood of questions, why something is not happening as expected.

Traditional measurement systems often describe the results and the results only. But they do not explain the cause.

Misconceptions

There are  some misconceptions.

Our hands are not only “holding” the club and the rest is done by body movement.

Our hands and fingers actively guide the forces into the club and how quickly or slowly these forces are developed.

Our fingers, left hand and right-hand balance, do the fine orientation of the clubface. Sometimes they turn the club even around its axis (very slightly), sometimes not. With a launch monitor alone, you will never see such a change- you only see the result.

Our hands do not merrily hold the club. The actively guide it throughout the swing.

However, these small changes, often in a timeframe of milliseconds determine the final result!

If these forces could be measured, an entirely new layer of understanding to golf training could be added

Hand force is more than “holding the club”

Many golfers still think of grip pressure in single numbers (because they have been trained like this):

“Grip so lightly as if you are holding a bird”
“Grip lightly”
“Grip firmly but not too hard”

The reality is far more complex than this (as we all know).

The grip pressure is not static.

Also, the understanding that the hand grip is similar like a homogeneous “force ring” around the grip, is wrong.

Although you hold the club with both hands, the force and pressure is not distributed evenly on the grip. Your individual fingers exert very different forces onto the club. The different areas of your hand palm provide very different forces respectively pressure to your grip.

It is not a static force, neither a homogeneous force around your grip.

During the swing, hand forces develop a specific pattern. While during the backswing, the force pattern is largely governed by your biomechanics e.g. how you have learnt to play golf and make your body movement, the downswing, impact and follow-through does have personal features, but is heavily governed by the physics of the movement (especially by the centrifugal forces after release).  Here just one short word:

“Grip so lightly as if you are holding a bird “- is a common advice. If you think about the details of release, it is clear that this advice only holds at the exact moment of release.

Holding your club like a bird during the centrifugal acceleration of your clubhead would just tear your club out of your hands. Your club would fly away.

This phrase helps many golfers for their swings. I think there is absolute truth in it however, you need to also define when this light grip is appropriate. It is certainly not enough throughout the whole swing. We will come back to this specific point in a little moment.

Understanding the dynamic of forces and their interaction with the club, opens new coaching possibilities and new possibilities for player development.

Instead of only asking:
“How hard should I hold my club?”

We can begin asking:

When should my pressure and force curve increase?
Which hand should have which force during the swing?
What is my thumb exactly doing during the swing and when?
Does the pressure pattern remain consistent from swing to swing?
How does my force curve’s change under pressure respectively when I’m stressed? How does it look when I’m tired?
What is the cause of my swing results variability?

These are questions golfers have rarely been able to answer objectively.

Completing the picture

Golf launch monitors transformed golf by helping us to understand the golf ball flight. High-speed video recordings transformed golf, by helping us to understand body movements.

The next step may be understanding the interaction between golfer and club.

It’s not to replace coaching nor to replace launch monitors or to replace experience.

But to complement them!

What we think as the ideal:

Imagine to combine all that information:

Ball flight data
Club delivery data
Video
Body movement and
Objective and force analysis

Instead of seeing only what has happened, golfers and coaches begin to understand why it has happened.

And this is the only way you can improve something! First you need to see it!

That is a fundamentally different way of looking at golf performance

A new way to think about improvements

For many years golfers have just accepted that certain aspects of the swing simply could not be measured.

Grip pressure and hand forces there often described using subjective wording like:
“6/10”
“relaxed”
“firm but not strong”
“active”

These descriptions remain useful, but they are very subjective.
Objective measurements have changed  other areas of the golf sport. There is every reason to believe, it can do the same for the hands.

Our understanding of how grip pressure changes throughout the swing – and how those changes relate to:

• release timing,
• clubface orientation and also
• putting –

may become one of the next frontier golf performance trainings.

Because before golfers can improve what they hands are doing, they first need to understand what their hands are actually doing.

They first need to understand what their hands are actually doing!

Before we analyse what happens during the swing, we first need a common language.

Throughout this guide will use a number of technical terms.

Understanding the language of hand force analysis

Before we analyse what happens during the swing, we first need a common language. Throughout this guide will use a number of technical terms. This unscientific, but there actually quite simple-and they’ll help you understand the rest of the article much more easily.

Understanding the language of hand force analysis

Our definitions

Hand force: this is the force the hands exert onto the golf grip.

To give an example, a man usually has a force of around 1000 Newton (N) with both hands, this means 500 N per hand. It is the force you will need to pull yourself up at the pull up bar, if your weight is 100 kg ( =220 lbs).
500 N total force from both hands is a very common peak force at impact when you are using a 7 iron and your ball flight distance is around 140 m ( 155 yards).

A professional player with a driver will reach far more than 1000 N !

Hand pressure, grip pressure: pressure is force per area. It’s just another naming to express your hand force on the golf grip. However, it is useful if you compare different hand sizes. Here differences between man-woman- junior players come in.

Force curve: it is the force development of both hands during the swing. For example, most golfers at takeaway are very relaxed and then increase their hand force during the backswing. All golfers have their personal way, how they perform the backswing. Biomechanics is an important factor, but this may be dominated by the way your coach has taught you golf ( even if many years ago).

When you start with downswing you relax your hand pressure during release (to be able to rotate the club).

When your club picks up speed, the centrifugal force increases put you hold your club back. Therefore the hand pressure increases –  because the club wants to fly away, but you keep it in your hands.

Force pattern: every golfer has a specific pattern of his or her force curve. There is always one peak during backswing, then a valley during start of downswing and release, and then a sharp increase when the club head motion is taking over with its centrifugal force. The most often seen force pattern has two peaks. One broad peak during backswing and one very sharp and steep peak after release and impact. “Ideally” (if you want to hit the ball with highest clubhead speed ) the impact is happening exactly at the top of this second peak.

Force variability: force variability are the differences in force curves when you compare 20 to 50 swings. A professional golfer has a very low variability, this means you can hardly see a difference between the curves.
Less experienced golfers have a large variability in release timing, impact timing, shape changes of the curve, althou typical, characteristic features always remain ( a “Swing signature”)

A very low variability in hand force, translates directly in a low variability in ball flight results.
Hand force curve and ball flight results directly correlate!

A high variability within a set of 20 to 50 swings translates into high variability in ball flight results. It’s not only the force maximum which can vary, but also the timing-this means the shape of the curve.

Auswirkung: in our terms impact = when the club touches the ball

Release: when the force through the centrifugal force due to the speed of the clubhead is taking over. This is milliseconds after you start opening the wrist. The release starts when you open your wrist angle. In a force curve it is the minimum point in the valley before the impact peak.
Release ends after impact.

Swing signature: this is your very personal force curve. We call it “signature”, because it is so personal, that even with different clubs the shape changes, however you still see your original swing signature. Exactly as with a  handwritten signature. Different writing instrument, smaller or larger written, still your signature is unique.