Conventional thinking around posture does not work. Simply telling someone to “stand up straight” or trying to use will power does not work. Sure, you can sit straight for 30 seconds – but as soon as you stop focusing on it, you end up slouching again. What’s worse for a lot people is it’s physically uncomfortable to maintain a healthy posture.
The best solution is to ‘correct’ the posture, so that it is more easy, more natural to hold the correct posture than to slouch. Of course there are many reasons for bad posture. It could be anterior pelvic tilt, it could be forward head carriage or scoliosis.
Bad posture can start from trauma like a whiplash, or simply and more commonly, from sustained poor posture. For example, spending too much time looking down at a screen causes classic ‘text neck’.