Having trouble getting back into pitching


It’s been about 10 years since I last pitched in a game(high school). I’m 26 now and while I can still perform my mechanics I’m having trouble performing them at same level I did when I was younger. My main issue is bending my knee when striding down the mound. It tends to lock up at a certain point and instead of being able to stride I instead end up hopping. Imagine Carter Capps or Jordan Walden but with less bend and a more pronounced hop…

No matter how many stretches I do or how many physical therapists I see I can’t seem to bend my knee like I used too and It’s become incredibly frustrating. As a result of it when I do get to my original delivery point I’m not able to throw because of having less time to separate.If anyone has faced any similar issues or has any tips/pointers they would be greatly appreciated.