As humans on planet earth, we have a very intimate relationship with the ground and gravity. If we did not have gravity we would be floating debris in space. Thankfully gravity keeps us connected to the ground. In weight training much of what we wish to accomplish is to overcome gravity in order to elevate the barbell, kettlebell, sandbag etc. It all starts with the feet.
Every movement we perform in CrossFit begins with a connection with the ground. That is the point of greatest leverage. So we must connect intimately with the ground. More often then not the feet are the main point of contact, not always, but mostly.
Since it is our greatest leverage point we must use it as efficiently as possible. We talk a lot about driving through the heels, this is important for sure but not the whole story. Really we should drive with our whole foot, toes heels, ball of the foot, etc. Think about using the entire foot to push into the ground.
The press series tends to have the most violations of this principle for whatever reason. The biggest offending movement is the Push Press. Over and over again I see folks upon initiating the hip dip rolling to the balls their feet before attempting to drive the weight overhead. Under heavier loads this action will not produce the desired result, the lift will fail as power will leak out.
Here is a checklist to think about: