This post is a roundup of YouTube videos but will eventually become a more complete resource page.
These are professional chiropractors and physiotherapist videos. If you search YouTube you’ll find a lot of non-professional advice and guys with their shirts off so I’ve tried to focus on people who know what they are talking about.
Be careful stretching! If you are suffering from pain then don’t do it and see a professional. Take it slowly and carefully because many of the moves below involve stretching under-used and tight muscle groups so don’t expect to be able to copy them exactly since you probably have reduced field of movement if you’re reading this guide.
The 10 Minute Daily Posture Routine
The 60 Seconds Daily Routine
Chest stretches targeting the pectorals
Pectorals becoming tight is linked to poor posture. Learning to stretch them and open the chest can really help.