Last updated: 26th October, 2018 2 most popular reasons for Knee pain while sitting and standing up due to Patellofemoral pain syndrome and knee osteoarthritis. Patellar Support Patellofemoral pain syndrome is the medical term for pain felt behind your kneecap, where your patella (kneecap) articulates with your thigh bone (femur). What will you feel? Pain on […]