Consistant Bad Lower Back Pain, 18 Years Old

During my final school year I spent alot of time studying under very strict conditions in school (around 11 hours a day inc. Classes) and ended up with a "misaligned pelvis" according to my osteopath (i think that's what he is, he deals with muscles etc.).

That was sorted out around last may/june and I had a great summer in terms of comfort and didn't really notice my back at all.




Now i'm in college (and I have to spend around 3hrs on the bus per day total) and my back is starting to really hurt again. Studying has become a complete hassle simply due to a sore back and it's very frustrating. I got up this morning with my back in ok shape, but after 25 mins on the pc it was very sore.




Examples to try and pinpoint what it is;
when I lean the top half of my body over, it feels like its pulling down in my lower back around where my belt sits and just below, but not as far down as the tailbone.



If I extend one of my legs as if kicking a football - straight out in front of me - it also creates a very sore pulling feeling in my lower back.



If it gets too bad it starts to hurt to walk and the pain and strain spreads further up into my back.




Sorry for the long post but i'm still young and don't know what keeps happening. I try and keep good posture and in all honesty I think it is fairly good.



Edit : I still go back and get it sorted now and again, and it feels well after I see him, but it comes back so I know the cause of the problem hasn't been eradicated

oh and it all started up again this time around after I had to stand with my school bag on my back for a few hours waiting for a bus, it really hurt that night when I got home but it seems to have triggered something, as it hasnt gone away.

And I do preform exercises every morning and night which help a little bit. One is where i'm basically curled up on my back with my knees being pulled into my chest, and the other is when i'm on my back with my arms stretched out over my head joint at the hands.