Our deceleration score was created to give you a snapshot on how well you are decelerating during the throw.
Deceleration refers to the ability to efficiently control your acceleration while not losing velocity. Deceleration involves both the upper and lower ½. During the quarterback throw, deceleration is critical to get the ball to “pop” off of your hand.
“Front-side stability” is a key component of deceleration for quarterbacks. This refers to the ability to use your front-side to adequately brace your rotation/acceleration. Front-side stability specifically refers to the front-side arm/hand, hip, knee, and foot/ankle complex.
The role of the front side knee and arm is one key differences between the quarterback throw and pitching in baseball. In pitching, the ball is being thrown from high to low (up on a mound and throwing downhill into the strike zone), and the pitcher has significantly more time and room for delivery. Because of these things, torso forward flexion and role of the front leg is much different between pitchers and quarterbacks. Pitchers will often post the front knee after release and get into extensive trunk forward flexion to generate velocity downhill into the throw.
In contrast, quarterbacks are throwing on a level surface, have to get rid of the ball quicker, and have much less space to work with. Therefore, quarterbacks must have a quicker stride and rely primarily on rotation in the hips and torso as opposed to a larger combination of linear and rotational force. In addition, excessive forward flexion of the torso results in loss of velocity (less whip through extension) and loss of accuracy (inconsistencies with release point). Therefore, the front knee must maintain stability to allow for continual rotation in hips/torso and prevent excessive torso forward flexion. Once the front knee extends, the torso will often fall into forward flexion and rotation will stop.
Our deceleration score is a “subtraction” score. This means every QB starts at 100% and then will receive subtractions based on the below things:
Hip-shoulder separation refers to the difference in the angle between the hips and shoulders. Proper deceleration should result in this difference being close to 0 at release (we are giving some leeway). This means that the hips properly decelerated and allowed the torso time to “catch up” and close the gap.
