I hope parents are still telling kids not to slouch.  Not because it looks bad, but because slouching is so bad for your body.   My boyfriend Matt is a sloucher.  In his case it is part laziness and part VERY tight muscles that make it difficult for him to sit up straight.  But whenever we pass an old gentleman who is staring at the floor because he can’t straighten his spine, I’ll point it out, and Matt will perk right up.  He doesn’t want to look like that.
So why is slouching bad for your body?  And why should Matt (and you) want to straighten up?
For starters, slouching changes the shape of your spine and where it curves.  Our curves are in a certain place for a reason and changing those curves can cause back pain and potential damage over extended periods of time.  Slouching typically causes us to jut our heads forward, which can create neck pain and may be linked to headaches.  Curling the body forward compresses the ribcage which can affect breathing and can be a culprit in a lot of chronic shoulder pain that isn’t helped through exercise.  And some day, you may find yourself staring at the floor because your back muscles aren’t strong enough to lift you.    Who wants that?  So straighten up folks.  Standing tall means your core is working!