Feels like the place to ask. At the moment I feel broken! I suffer from a bad back and have for ages, not so much now but still on some occasions when I stand at the sink doing washing up my lower back aches. About 3 weeks ago I was challenged to do this push up, arms out flat in front and try to push up, in doing so I over extended and I both felt and heard crunching/cracking in my back. Hurt at the time and I am still getting some pain there. Feels almost bruised about 1/4 of the way up my back.
My back pain started with my job at Honda, I was working on chassis which meant I was under the car for my entire shift and I was on the same job for about 9 months, no rotation of jobs like I was meant to get every break. With my hard hat on I was slightly to tall to be under the car and for duration of my task was leaning backwards. 9 months solid of doing this for about 7+ hours a day it appears to have really screwed with my back. I do have tight hamstrings and a slight tilt in the pelvis which doesn't help but after every gym session I make sure to stretch out well now.
Any idea what I may have done to my back? I am a postman now so spend a few hours a day walking with a bag over my shoulder and I can feel it at times, back just turns into one giant dull ache and gets quite uncomfortable. What are the chances I have cracked something? It certainly sounded like I did at the time.
I also really need to sort my shoulders out as they are pretty terrible with regards to mobility, I tried doing that test where you put one arm behind your back and one over the top and try to join fingers, can't even get close on one side! I do some door jams to try and loosen up my pec area, I do shoulder stretches like arm behind back and holding onto a frame/bar to stretch out my front delt area. Also do some resistance band work working exterior rotations.
Sorry for the long post.
Sounds like the best thing to do with your back is to seek professional advice, apart from anything else we can't really see what is wrong over the internet. Although it may seem expensive it really is worth it.
From a non-diagnostic point of view healthy back comes from healthy hip, shoulders and a properly functioning core. Try the hip stretches in the first post, you will probably find that the ones that target the front of your hip are the worst but do them all. Shoulders, same thing.
Just do what you can with regards to stretching. If it hurts too much or not in the right place stop and reassess, are you doing it correctly, are you trying too much too soon, are you comprising the position of another joint. . . All important things to consider. Also try and do some general rolling before stretching, just hit major groups like feet, leg, back and chest just to act like a warm up.
Core training wise, this gets a little lengthy but find the time to do a bit of reading and watch these videos, then it'll be a little easier to get into what is important.
http://www.5min.com/Video/Kelly-Starrett-of-Crossfit-San-Francisco-517516680
You need to try to understand what muscles make up your core and how they work individually and together. The first two are more theory based about how posture affect people and the third is a quick video which explains how to use your core properly during exercise. If you do go away and do some exercises try to use keep in mind the principals in those videos.
Sorry for the lengthy post, I hope some of it is useful. I really can't stress enough how important it is too see a professional about it though, it will make everything much easier for you.