- Cool workout. Nice "clean up" workout for a "sore-maker" week.
- HS = high speed.
- Extend and bend arms fully with EACH REP.
Your shoulders HATE to be loaded with high resistance while rotating the humerus (internally OR externally). They especially hate being resisted during external rotation. Compare the muscles of internal rotation (BOTH pics on the top row), to the muscles of external rotation (piddly one on the bottom). Is it any wonder you are weaker while rotating your upper arm away from the front of your body?
That's why you have to be careful while doing twist punches, high sumos and other exercises where you might have a tendency to try and externally rotate your arm while it is resisted. Those little bitty muscles won't hold up to much abuse! Potentially it can cause serious injury.
BTW - can you name all the muscles pictured above?