For a situation like this, it may be benficial to stretch the external rotators so that I give my internal rotators a fighting chance when learning the skill.

This is just one example but, since the shoulder is much more complicated than the hip joint it is likely going to have multiple ways in which you can stretch to improve performance or prevent injury depending on the client.

Just my opinion; Food for thought.

Not statistically relevant for beginner and intermediates most likely, but once you start getting to the advance/elite level where you need to be working 100% of your ability for adaptations it starts to make a difference. That may be a difference of 20-25 lbs on your deadlift or .1-.2s on your 100m sprint.

For upper body shoulder mobility is going to be the key to keeping people injury free. If they have significant amounts of caveman posture — e.g. rounded thoracic spine, hunched forward shoulders (tight chest, lats, pec minor), weak scapular retractors and external rotators, etc. It is probably beneficial to stretch out the chest muscles specifically especially for anterior dominated movements like bench press.

Proper mobility and functioning to remain injury free over small gains anyday.

Do you recall the percentage of decrease in max power output for those who static stretched before a workout? I seem to recall Mike Boyle stating it was somewhere around 3%.

With that in mind, I will static stretch any and all clients who have some sort of shortened muscles and ROM (as you mentioned in the last paragraph). The loss of power is worth an injury-free client.

Finally, any upper body static stretches you find beneficial before exercise? In other words, an upper body equivalent of the hip flexors? I’ve found soft tissue work and stretching of the pec minor and traps/levator scap to hep in shoulder movement and function.

You’re the man Steve, would love to hear your thoughts.