This will incorporate environmental elements for instance wind, chilly, dampness and heat, and injury; and interior components which include liver and kidney deficiencies, or Qi and blood stagnation. The obvious way to diagnose a PCL tear is to examine the knee for posterior sag at 90 levels of knee flexion https://www.theorthopaedicandpainpractice.com/what-happens-if-i-injure-my-posterior-cruciate-ligament/