Rounded shoulders can cause a number of shoulder issues.
As the shoulder blades move forward they limit the space the rotator cuff tendons have between two of the bones of the shoulder.
This limitation in space can predispose the cuff tendons to impingement, fraying, and tearing.
Space is also reduced between the clavicle and the first rib which can close down on nerves and blood vessels and can lead to pain and numbness all the way down to the fingers.
Over time, rounded shoulders can also weaken back and some shoulder muscles by positioning them in a state of constant stretch.
These muscles can lose their capacity to keep the shoulder joints in optimal positions for pain free movement.
Read more: http://www.integrativepersonaltraining.com/blog/shoulder-impingement-and-neck-issues-from-poor-posture/#ixzz3gu8cFKgc