Hi bill 1987
I am not a qualified therapist in anyway but I have been doing sport all my life and have learned how to read my body's aches and pains... I hope the following helps:
-there are some injuries that are so painful afterwards that you just have to rest them..the pain that you feel tells you to back off
-there are other injuries that are a bit painful where you can exercise/stretch it a little and then back off and let it rest further
-maybe after a few days rest you could try mimicking the exercise movement with no weight and see how painful it is...if you can't mimick the movement because it's too painful then certainly don't add weight and rest the arm more...keep trying this until no pain is felt then add a very light weight...it's like a try-it-and-see situation
I have only ever incurred one real injury in over 30 years all the rest were twinges where I would back off my training until the body adjusted. I took up snowboarding 3 seasons ago and was getting some good speed down the slopes but unfortunately I collided with a skier who was built like a tank compared to me...needless to say I went flying through the air...I landed on my shoulder and damaged my rotator cuff... I could not move my arm and I could not move to the side of the slope for feeling winded and sick...
...Anyway, this shoulder took a year to heal...I done absolutely no exercise on it for 3 months because everytime I tried to move it in a certain position or put pressure on it.. the pain told me to back off...eventually I could move the arm with little bits of pain and over the weeks I could move it further still with manageable pain but never straining the arm....now I have full mobility and it is more flexible than the non injured shoulder/arm
Just thought I would share these suggestions with an example

If in doubt maybe see a doctor
