Before this man is permitted to touch a barbell, he must first do his 30 min prep. Out comes the lacrosse ball, and he rolls his glute on it on the gym floor with the face of a man receiving terrible news over the phone. Then the foam roller, the full length of each leg, wincing theatrically at knots he has decided are there, even though science cannot yet see these knots. Then the little resistance band, looped above the knees for the side-steps, the monster walks, the clamshells, the entire physical-therapy waiting-room routine. Then the band gets hooked to the rack to distract his hip capsule, whatever that means, while he hangs off it and makes a face. Forty minutes in, glistening and deeply warmed up, he is at last ready to lift, except now he is tired and it is time to go home.
He calls this mobility. He has decided he is tight. He is always tight. Tightness is his whole personality and his eternal works-in-progress, and no amount of rolling ever finishes the job, which he reads as proof that he needs to roll more, rather than proof that the rolling does nothing.
Here is the secret nobody at the band table wants to hear. Most of what you are calling tightness is weakness. The muscle is not too short. It is uncontrolled past a certain range, so your nervous system, very sensibly, slams on the brakes and guards the position, and that guarding feels exactly like tension. You then attack the feeling with a lacrosse ball and buy yourself maybe ninety seconds of borrowed range, gone by your second working set, because you did not make anything stronger. You sedated the alarm. You did not fix anything.
The actual cure for being weak and shaky at the bottom of a squat is, and I am sorry that an entire industry of rubber goods will hate this, squatting to the bottom and getting strong there. Load the range you cannot control until you can control it.
Load the range you cannot control until you can control it. Said it twice because it's that simple.
Strength in a position is what convinces the nervous system it is safe to let you into that position in the first place. That is mobility. Real mobility is just usable strength at the end of your range, and it is built with load, slowly, not purchased in rubber.
Some restrictions are valid though. Warming up is great and very useful. I am not telling you to stroll in cold and sprint for your life. I am telling you that prehab is, most of the time, bad programming in a lab coat holding a lacrosse ball, and that if your warm-up runs longer than your training, you do not have a mobility practice. You have an elaborate, sweaty, deeply sincere way of avoiding the one thing that would have actually changed your body, which is getting strong somewhere you currently are not. Find a way to strengthen whatever is tight and weak and you'll see how it relaxes.