You can pull your knee to your chest? Nice! Your hamstrings are pretty flexible. Ok, but can you keep your knee there once you let go with your hands?
This is the difference between flexibility and mobility. Flexibility is simply PASSIVE range of motion. You can achieve this by relaxing deeper into a stretch or having someone push your leg
Mobility is a step beyond this and includes the ability to ACTIVELY control that range of motion. In your end ranges of a stretch you should be able to hold weight or control the movement without assistance.
We focus on mobility so you can use the space your joints give you. Instead of just stretching we add strength to your new ranges of motion. This way you can create more force, be more powerful, and stay safe.
If you rotate in a sport like golf or baseball you should be able to rotate your spine very well. It should be flexible. However, if you rely on getting out of your max rotation quickly so that you can begin firing the muscles you have control of you’re missing out on using muscle earlier in the swing. You should strengthen the end range of your rotation so that you can begin to rotate with power earlier in the swing.
Activities like wrestling or Jiu Jitsu demand strength at end ranges of motion. If your opponent gets you into a compromising position stretching one of your joints to its limit you will have a greater chance of escaping if you are strong there. If you fail to build strength at these end ranges of motion you can no longer resist in those positions.