Recently I was posed the question, why should i push so hard to get my knee to move to 120 degrees when I am at 110 degrees of knee bend. I am older and seem to be able to do everything that I want to do at home with my current knee mobility.
Well… my current thought was relayed as follows.
Two reasons. Establishing a buffer and motion primes muscle.
It may take 110 degrees to perform most tasks, but what about the story you told me when you were navigating steps into the attic and you dropped an item that you needed to pick up. Did you have the ability to perform that task? Having a buffer is important.
Being a male weighing close to 200#, I generally would rather sit in a chair rated for 250# versus a chair rated for 200#. You never know when you may need that extra bit of buffer to address the unusual or unexpected demand.
More importantly motion primes muscle. A person does not jump without first bending knees, hips, and ankles. You cannot kick a ball forward with any force without first kicking backward away from that ball. Motion precedes muscle function as it primes the contractile tissue to fire. If you are missing motion you will be less efficient in stimulating the receptors to perform in their respective roles involving functional activities.
Why is she kicking backward to kick the ball forward? Because motion primes muscle. She is providing a quick stretch to the tissues on the front of the torso and right leg and they are gonna fire and blast the heck out of that ball.