I have been following his routine for ages and do these exercises religiously at least 3 times a week. I never really had any problems, but I am feeling much stronger and more flexible when shooting my bow. I can lock on anchor and hold longer. However, I think the best thing is the 'pinch'.
This is not a normal movement that we follow in an exercise routine, or everyday use of out sholders. I believe that is the key to why this routine is so good. It is making us use the full range of movement for our shoulders, but in a stable, slow moving manner that will not create injury. By holding that 'pinch', it is building into our shoulders and back an 'insurance policy', against injury later on. They only take a few minutes to do and I challenge everybody to get on this regime. I have built up and do them now with small weights - I could not at the beginning, but obviously my shoulders have strengthened, so I am able to build and load on more resistance.
Sutto