Not sure what you've tried in the way of stretching, but I have some advice that you can take or leave, that I learned in my time in the Marine Corps, where I w

Not sure what you've tried in the way of stretching, but I have some advice that you can take or leave, that I learned in my time in the Marine Corps, where I was doing MMA, running, lifting and swimming 5 times a week for about 4 hours total of exercise a day. (I got a bit fat and lazy as a civilian but I'm working on that these days) First, most people don't spend enough time on their stretches. The most common mistake I've found people have in their stretching is they only do a stretch for ~30 secs to a minute. Try spending exactly 5 minutes on each stretch, and I mean each stretch even if it's on the same muscle group, which brings me to two. The other main mistake I've corrected family and friends on is lack of variation in order to target the full area of muscle fiber on a muscle. They do one stretch in one position for a certain muscle, say, hamstrings, and think thats it. Even if you spend the amount of time suggested, if you dont target the whole muscle you will just have a small line of flexible muscle fiber while the rest of your muscle doesnt. Let me explain, so I'm sure you already know the standard hamstring stretch either single or both leg style. The best way to vary a hamstring stretch is to rotate your foot. First, to the inside, then to the outside. You will notice the different muscle fibers it gets. Then you should also try variations with your foot as far away from you as possible, and as close to you as possible. Try adjusting your hips on the single leg hamstring stretch to get slight variations as well. This is just an example, almost every stretch has small variations like this that pay off great dividends if you do them regularly. In total, during my fit days, I was spending about 30-45 minutes each morning and each evening stretching, with random quick pnf stretching done throughout the day. I know that sounds like a lot of time for a busy person, but, it's not that bad if you multi-task (I usually read news in the morning while stretching, and evening stretching is more meditative), and can you really dismiss your health so easily? Now, everyone is different and you might indeed have wierd biomechanics, but respectfully I think you might have allowed it to develop to this point rather than it being your natural state. My suggestion for you would be this, start with the above time/variation stretching suggestions, and throughout the day try to keep your abs flexed for 10 minute intervals a few times a day, maybe setting reminders about posture every so often. This is what I tell any friends or family who go on a get fit or fix my posture kick. Stretching is the most important part of either!