Hello, I have had this terrible pain in my left bum cheek...feels like the muscle has been kicked and bruised. I ve been told it s sciatica, and or TFL. The pain does not go all the way down my leg. It stops behind my knee, but is not at the outer side of my leg, only down the back when I sit, but the bum hurts all the time. I can push on it, massage it and the only thing that really helps is taking arnica. I am a runner, but was biking when it first started hurting about 6 years ago. Felt a sharp sting down my leg when I got off the bike and it never has gone away. Do you have any ideas?