Pain in upper inner thigh?

I have intermittent pain in my upper, inner thigh. When walking around this pain is so sudden it can knock me off my feet. When sitting, if I move my leg (right) I can recreate the pain and feel it through to my buttocks. If it strikes when walking, I’m left with a very sore knee as well as the inner thigh. Can anyone help me with this. It is very debilitating!!!!!