Part One: It’s Impulse!
By Jim Fanara, CSCS
The force that creates a high velocity lacrosse shot is the same force that sends a passenger flying forward as a car hits a wall. In physics terms, it’s called Impulse.
Impulse is what changes an object’s Momentum. Impulse is the product of Force and the Time during which a force acts on the object. Momentum is Mass times Velocity. A 20 car passenger train going 55MPH has more Momentum than an SUV going the same speed. But if the SUV hits a wall then its Impulse is stronger than that of the freight train gradually stopping over 2 miles. Just ask the passengers!
Why the quick physics lesson? Because Impulse and Momentum create shot velocity.
The Impulse equation tells us that something quickly stopped has a greater impulse than something gradually stopped. The greater the impulse the more force is transferred. Even a very fast moving very small car that suddenly stops would send a passenger violently into the windshield without the restraint of a safety belt. It’s the same with a lacrosse player and the ball.
If you have two players of equal size and strength, running at the same speed and possessing the same shot mechanics, the player who can decelerate the fastest will have a stronger impulse and the higher shot velocity. Therefore, even a fast runner with solid shot sequencing mechanics will “leak” shot velocity without a quick halt to forward momentum.
Studies indicate that elite lacrosse athletes get the most advantage from impulse to create rotational velocity. Rotational velocity powers a lacrosse shot.
How do high velocity shot makers use impulse to convert forward momentum into rotational velocity?
Elite shot makers display five key characteristics when shooting. They can:
- Rapidly Decelerate and Stabilize the Lead Leg
Rapidly Decelerate The Center-of-Mass
Create Separation Between the Hips and Torso
Effectively Resist Rotational Forces using a Stable Lower Body and Core Bracing.
Unwind the Shot Using Stored Energy of the Lagged Deceleration Sequencing: First Hips, then Torso, then Shoulders, then Arms and Finally The Stick.
Combining these five components of shot making enables the athlete to quickly decelerate by firmly planting the lead leg while maintaining upper and lower body control. Then a coiled torso winds up on a stable anchored hip. Unleashed power travels thru the torso, then shoulders, then arms, and then the stick unwinding in sequence to whip the ball toward the target.
Part Two: The Lead Leg