Bryce Harper has taken the game of baseball by storm. One of the key attributes to his swing is the rear leg/foot and the coverage of his stride. Hitters often attempt to emulate the action of his rear leg and in this article we take a look into some of the swing sequence attributes that lead to such an explosive lower half.
One of the more noticeable features to Bryce's gather is the inward turn of his front leg. This inward turn accompanied by the stable rear leg allows the rear hip to load. We see evidence in this as his front hip appears to lead the forward stride as the knee remains "closed" away from the pitcher. A large part of his swing sequence that creates such an explosive lower half is his ability to continue striding with that lead hip closed, not losing any potential energy as his stride leg begins working into the ground. The term that we refer to this action is that the rear leg "swings the front foot into position". If the lead hip begins its rotation too early, we begin to leak energy and work to a more pull-side heavy approach. Notice the image below and you can see how early the lower half clears in relation to the lead shoulder. This separation or disassociation of the hips and shoulders acts as a mechanism to build tension and unload the swings momentum ultimately delivering the barrel.
Bryce's ability to load into and against the rear hip/leg is what allows for much of the control and sudden release of the energy. You can see the angle of the rear leg straighten as he works into his forward momentum caused by a strong connection from the rear heel. This allows him to hold that tension through the stride and then release as his hands are continuing their up and back pattern.
The "Scissor" Effect
Building off of the immense torque created in Bryce's rear leg, we see what we cal the "scissor" effect as the rear leg and lead leg essentially pinch together. When the hitter stays loaded through the rear leg with good heel connection, that aggressive hip turn causes the sequence to pull that rear foot from the ground and forward. This is very evident in the video below as you can see the rear foot "pull" forward and slightly behind the rear heel as the back foot released from the ground. This is a staple visual effect that we see with Bryce's swing.