The knee joint is surrounded by fluid-stuffed sacs known as bursae, which function gliding surfaces that reduce friction on the tendons. Below the kneecap, You will find there's massive tendon (patellar tendon) which attaches on the front of the tibia bone. Engaging in sports is the most typical danger variable 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