I have been having this pain in the lower left hip/lowerback for a month or so now and I am starting to get very frustrated as to how it does not seem to want to go away...

I have set my mind to do whatever it takes to fix the injury as it prevents me from doing any sort of heavy lifting in the gym, and obviously the first step to fixing the injury is to identify exactly what it is.. I figured at first it must be some sort of deadlift injury, perhaps I have been lifting too heavy, with bad form maybe (unlikely though as I do use a belt and focus on form).

But thing is I do not get pain when copying that sort of deadlift movement, for those not familiar with what a deadlift is it is basically picking up a weight from the ground and lifting it up with your arms/back/hip while maintaining a straight back, and like I said I have no problem doing this sort of movement

What gives me pain though are these very weird movement of my leg, for example I do boxing sometimes and when I move around the bag hitting I feel sharp pain in the lower hip/lower back every now and then when I move a certain sort of way, now I have come to figure out what does trigger the movement is me pulling my left leg backwards, not lifting it up backwards but actually having my left leg foot on the ground then sort of trying to pull the ground backwards, whenever I put that sort of pressure on that leg it gives me incredible pain in that spot that has been bothering me...

I have never heard of an injury like that and I am ready to go visit a doctor for this but I wanted to write a few posts on forums just to see what you guys say and think first, in case this sort of thing can be fixed through light strech and rehabing on my own

Sorry for the long text and thanks in advance for all help