I am not convinced at all that someone needs to do EXTRA internal rotation exericises

The only thing I can add is that I am not convinced at all that someone needs to do EXTRA internal rotation exericises. Like I told you before, almost all your major upper body exercises involve some aspect of the internal rotators. The internal rotators are huge muscles. Especially compared to the external rotators.

The major internal rotators are the lats, pecs, teres major and subscapularis. The first three for sure get worked in abundance and are going to tend to be dominating to the externals. What you'll find is disagreement about the subscapularis. Some will say you need an isolated internal rotation exercise to hit that muslce. It is a muscle that lies underneath the scapula hence the name. The mistake people make is that they think it is very tiny like the externals because you can't see it. But in fact it's pretty darn large. The will say it will be inhibited by the larger internal rotators and thus cause imbalance (it is an important humeral stabilizer)....so it needs to be strengthened.

The problem is this assumption doesn't seem to be indicated by research. Basically if the internal rotators are hypertonic and dominant the subscapularis will be also. I've never seen anything to indicate that the subscapularis becomes inhibited by the other internals in the general shoulder disfunction syndromes. If anything it tends to become OVERWORKED if the scapular movers and external rotators are weak because it will have to take over some of the stabilizing role...of for instance the suprispinatus.

You know I have a lot of respect for Eric Cressey but I disagree completely with his statements about working the subscapularis. Until he shows me some examples of it being inhibited which he has never proven.

So to sum it up....I would avoid "internal rotations" as a prehab excercise. That is, the actual isolated type that are supposed to target the subscapularis more. There are other prehab type exercises that may involve some internal rotation but will also hit some other small but important muscles. This is fine but just keep in mind the relationship I layed out about the abundance of internal rotation in the average program. It is also important to stretch the lats and pecs for this reason. However I am not talking about DC style stretching!