One of the safest ways to stretch your upper chest and shoulders is using a rubber band. The band should be rapped around a solid stationary object (like a squat cage) above the clients shoulder height.
Have the client outstretch their arms with elbows locked, moving forward slowly. The bands will pull up and backwards against the chest and shoulders. This hold should be for 20 second bursts.
This chest / shoulder stretch exercise is my favorite, right after bench press or military press training.
The video below shows my client rehabbing her shoulders after a 30 minute workout specifically for re-strengthening them after her automobile accident.
https://youtu.be/B9PTm7qXbhI
