If you have patellofemoral pain syndrome, you probably already know the feeling well: a dull, aching pressure behind or around the kneecap that flares when you go down stairs, sit for long periods, squat, or run.

The burning sensation on the outside of your knee that starts around mile three, fades with rest, and returns the moment you push volume again — if you recognize that pattern, you already know how disorienting iliotibial band syndrome can be.

Popliteal tendinitis does not get the same attention as Achilles tendinopathy or patellar tendinitis, but for anyone who has dealt with persistent lateral knee pain while running downhill, cycling, or changing direction repeatedly, it is every bit as frustrating.