My wife has dealt with this issue off and n for years. It's very frustrating, to say the least. She usually has to rest hers for a few weeks, to let the "acuteness" of the injury settle down. Once they are not hurting all the time, she focuses on doing eccentric exercises to help with the pain or achiness. She feels those have helped her but she always has to start off slow, with low or no weight

Would agree with above.

Rest only necessary at the very beginning when pain is intense - then it doesn’t help much (or would take an excessively long time)

Need to rebuild that muscle and it’s supporting areas and strengthening is key.

I don’t know what exercises to recommend but I’m positive YouTube is full of some suggestions for quad tendinitis

Note that when strengthening, the first time you start doing it you might feel like it’s getting worse before it gets better

Good luck

Have a look at this website... https://www.sportsinjuryclinic.net/...-hamstring-exercises

Anytime someone starts talking about being tight somewhere, I always like to refer them to anatomy slings. Only stretching the so-called tight muscle will yield zero results. Have a look at this info and see if it helps. You really need to stretch the entire chain. And this applies to everything, not just low back. https://www.physio-pedia.com/...hip_to_Low_Back_Pain