top of page

Unleash Incredible Power in Golf with "impulse index"

One of the keys to success in golf is the ability to generate power while maintaining control over the ball's trajectory. A concept that has garnered a lot of interest for generating power is what I call "impulse index". Although this may seem mechanically complex, we will try to simplify the description to make it more intuitive.

The Impulse Index: What Is It?

Impulse index is a concept that describes a golfer's ability to propel their sternum upwards at the crucial mid-downswing moment. This action, when triggered at the right time, can be considered a key to developing maximum power in a golf swing. To better understand the sequence of effects that lead to this impulse, let's define some intuitive notions characteristic of the downswing.

Intuitive Notions

Starting with a ruler that we try to balance on the hand, if the ruler tilts forward, I would move my hand towards the side where the ruler falls to try and reposition it back to balance. This is called Situation A.

Situation A

By opposing a movement of the hand that goes in the same direction as the fall of the object, we put the ruler back in balance.

Situation B

  • We start in balance then the ruler falls forward.

  • We move the hand on the opposite side of the fall of the ruler, thus amplifying the imbalance and increasing the fall speed of the ruler.

Experience this physically with your golf club...

Intuitive Notion 2:

Now transpose this idea to your golf swing. Take your driver and place the end of the grip against your sternum. This creates a natural pendulum. Try to accelerate the club head now. You will quickly notice that the best way to accelerate the club is to create an upward acceleration when your club is parallel to the ground.

Application in Golf:

We make the transcription from the example of the hand on a simple rigid pendulum:

  • The rule

  • The hand

We make the transcription to a swing:

  • If the player wants the rule to fall down faster, we move the hand in the opposite direction to the fall (Situation B). I increase the hand/club speed by moving the center of rotation to the left.

  • From topswing, the more significant the lateral movement speed of my rotation center, the greater the impact of this movement on the acceleration of the hands/club.


Small problem from mid-downswing:

  • If the player continues with a strong lateral speed to the left, it opposes the speed of the hands/club: the rotation center moves in the same direction as the torque of the hand/club, which is Situation A.

To continue to be effective, it would be necessary:

  • Stop, better reverse this speed to the right in favor of a speed to the left (to be in Situation B):

  • To continue to accelerate the hands/club, after mid-downswing, a vertical speed is realized (which is also a Situation B):

The vertical speed is particularly important as it stops the lateral transfer to the right, which has become detrimental to efficiency, and it becomes a generator of efficiency to maintain/increase the acceleration of the hands/club.

Ideal sequence would be:

  • TopSwing ⟷ mid-downswing

  • Mid-downswing ⟷ impact

The examples provided are based on extreme simplification. For the brave, we refer you to the article by K. Muira ("Parametric acceleration – The effect of inward pull of the golf club at impact stage. December 2001 – Sport Engineering 4(2):75-86"). The author proposes to study a model of a double pendulum with a "parametric excitation" of the rotation center. He shows how the model allows for characterizing an increase in club speed at the moment of impact from an elevation of the rotation center.

During the final phase of the swing, a significant elevation of the rotation center can only be produced by very powerful muscle groups. Those who have analyzed the swing with force plates have noticed the increase in left leg thrust at the moment of impact. This left leg thrust is the cause of the elevation of the rotation center, provided the player can transmit this impulse without energy loss at the level of their pelvis and chest.

Below is an example of the 2D trajectory of the rotation center measured with the Biomecaforce system:

Impulse Index Among the Biggest Hitters

Professional golfers and the biggest hitters in the world are known for their ability to achieve the K effect impulse index in record time with maximum power. They have mastered the art of propelling their sternum upwards at the precise moment of the mid-downswing, allowing them to release an impressive amount of energy into the golf club. This results in long and powerful drives that impress both spectators and competitors.

The speed with which these golfers accomplish the K effect is often astonishing. Their ability to synchronize their bodies optimally and to release the power accumulated in the club is the result of many hours of training and experience on the course. They have perfected this technique over the years to achieve extraordinary performance levels.

Ability to Deliver the K Effect Impulse Index with Age

It is important to note that the realization of the K effect impulse index and its execution evolve with age and intimately depend on the physical capabilities of the player. Older golfers can continue to develop their power, but this often requires more meticulous preparation in the backswing and an earlier reliance on support that gives them the time to place an effective impulse. As the body ages, it may become more difficult to maintain the flexibility and mobility necessary to quickly achieve the K effect.

Even among amateurs, the search for efficiency requires older golfers to invest more time and effort in their physical preparation. Of course, this preparation must be adapted to the capabilities of the players but it can allow them to work on their flexibility, strength, and coordination. This will enable them to compensate for any possible age-related limitations and continue to generate significant power in their swing.

13 views0 comments


bottom of page