The knee joint is surrounded by fluid-stuffed sacs named bursae, which serve as gliding surfaces that cut down friction of your tendons. Under the kneecap, You will find there's substantial tendon (patellar tendon) which attaches on the entrance of your tibia bone. Be sure to hold out a few minutes https://www.theorthopaedicandpainpractice.com/what-should-i-do-if-i-have-a-collateral-ligament-injury-of-the-knee/?_gl=1*xbbxlb*_up*MQ..&gclid=Cj0KCQjwkt6aBhDKARIsAAyeLJ2krYJSOuy5mZksrNqH-VDjQwW1ScD49yD8BUWysDG6u6bJPCSbXVUaAuCPEALw_wcB