Today I found some photos and an old video we filmed a few years ago. This exercise is very relevant to a lot of the postural problems I come across on a daily basis. Poor upper body posture can be linked to several problems such as shoulder pain/impingement and neck pain. Poor posture may be something you are born with, but more often is it linked to muscle imbalances. A simple exercise to target the muscles at the back of your shoulders is "scapular wall slides" (mainly rhomboids and middle trapezius). I have attached a video clip so u can have a look. 3 key points to consider on this exercise:
1.Try to keep your back in contact with the wall
2.Keep pushing your elbows and back of your hand into the wall
3.Pinch your shoulder blades together
Give it a go, it may look simple, it's not if you do it properly.
Apologies for looking serious, just very concentrated :) It is a great exercise so please try it out!
Let me know how it feels!