Hi there, I'm not a physio but have trouble with my own IT bands and I just wanted to mention that during the clamshells I found the best way to ensure the glute medius works is to think about pulling the hip into the socket as you lift the leg, initially I found I actually had to pull the hip into the socket then lift the leg, but progressed to just having to think about doing it which cues the glute medius up before you start. Hope that helps.