Biomechanics of Pitching – Why Timing is Everything

We are a few weeks into our educational series on pitching! [Sign up here to join all future weeks, or buy Stream S2 to get access to the first five weeks]. Our goal with this education series all along has been to change the conversation around pitching development, performance, and coaching. We take a very data-led approach at OGX and sharing that data, through a series like this, is an important part of the evolution of softball pitching.

Let’s recap our Week 1 discussion.

We kicked off the series starting with laying out how we see pitching through a biomechanics lens and stressing the importance of trunk-arm timing for softball pitchers. Pitching is a series of events, resulting in the creation, conservation, and transfer of energy through the kinetic chain. Every pitcher will accomplish ball delivery through this kinetic chain of events but not every pitcher optimizes the sequence. At OGX, our approach is that velocity, break, and pitcher health/wellness are rooted in quality pitching patterns and kinetic chain optimization.

pitching as kinetic chain

So, what does kinetic chain optimization mean for a softball pitcher? At its most basic level, it’s her ability to create a trunk-arm timing that allows her slot effectively into layback and prepare for ball delivery. To accomplish this, the trunk must give the arm time to get overhead while it maintains its length. In order for the trunk to provide time to the arm, it needs time in the air once the pitcher has left the rubber (launch, “3 o’clock”). Time in the air depends on the load she is able to create before she leaves the rubber – hinge at the hips, knee flexion, knee over toe via ankle dorsiflexion (“shin angle”). This load, plus a coil created by the chest, creates power for push-off that translates into both vertical and horizontal movement of the pitcher’s body and the initiation of hip rotation she will need to give her arm time to do its job. 

transition from load to launch softball

This transition from load to launch is critical for setting up the rest of the kinetic chain of events. The pitcher goes from a closed-kinetic chain (feet firmly on the ground) to an open-kinetic chain (drag foot in contact with the ground but not producing any energy) and essentially airborne. Post-launch, her trunk must maintain stability (“vertical stack”) AND allow the chest and pelvis to rotate independently of each other (dissociation/separation).

The trunk will change direction not once, but TWICE, during this airborne phase. The first occurs as the arms are extended forward and the chest faces the catcher right at the moment of launch. If her load has been appropriately accomplished, her pelvis has started to rotate toward 3rd base (for a right-handed pitcher). As the arm works overhead, her chest and pelvis will sync back up for a brief moment, before her glove arm stretches on her anterior sling (left abdominals to right adductors for a right-handed pitcher) and initiates back hip rotation toward the catcher. 

trunk control - pitching biomechanics

Once stride foot contact occurs, the pitcher returns to a closed-kinetic chain. Stride foot contact should occur before layback to give energy from this landing time to transfer through the trunk to the arm. The stretch along the pitcher’s anterior sling (left adductor to right abdominals for a right-handed pitcher) coupled with the arm achieving layback (maximum external rotation) leads to the delivery of a strong whip via shoulder internal rotation and forearm pronation.

The take-home message of the entire discussion was to make it clear that arm position at layback is dependent on trunk position and control throughout the motion.

Often in traditional pitching instruction and coaching, the symptoms of poor trunk control (arm path, neck position, glove arm use) are attacked without addressing the underlying problem: leaks/non-optimization of the pitcher’s kinetic chain. Optimization relies on understanding the biomechanics of the pitching motion and when and where the trunk is going wrong.