Acute back pain is often the result of muscle sprains or strains. Sprains occur when your ligaments are overstretched and sometimes torn. Strains, on the other hand, are caused by stretching — and possible tearing — of your tendons or muscles. Though the immediate reaction is pain in your back, you may also experience dull aches or discomfort in your hip.
I think you should mention that for some people, stretching is not the solution and that it will deteriorate their posture. Some people need stretching, but most people I know need to strengthen their "overstretched" hip flexors. Many people can't do a single hanging leg raise. Check this site if you want to know more about the importance of hip flexors bit.ly/Unlock_Your_Hip_Flexor Report
I’m just going to briefly touch on this because this will look different for each person. But know that if your hip flexors are or always feel tight, there is a reason. Muscles don’t get tight with no cause, and it’s usually because they are compensating for a weakness elsewhere or are constantly in a shortened position (as is the case with sitting).
Since someone has to do the job… (Side note: That’s one of the coolest things about our body. There is always a backup system. Always another set of muscles ready to take over. Even if they are not the most effective and it leads to pain and tightness.) So, who takes over for spinal stability when the abdominals aren’t fully working? The psoas of course.
A sedentary lifestyle can lead to having weak and tight hip flexors as they are always in the shortened position. Tight hip flexors can lead to a limited range of motion, poor posture, lower back and hip pain, and even injuries. These muscles need to get a workout when you are standing and doing movements such as raising your leg to climb stairs, run, or ride a bicycle.