Start out with it with a really wide grip with straight arms in front of you. With straight arms bring the stick up and overhead and then down and back to the middle of your back. STRAIGHT ARMS ALL THE WAY (this is going to be very difficult and hard the first couple times out and then will be "old hat" with time - and its going to be painful in a stretching pump kind of way). Do 50 reps each time you do this - one repetition is from in front of your face (all with straight arms) to up overhead and back, and then down all the way to the middle of your back and then back up overhead to in front of your face again (again all with straight arms).
The important part of the movement is the area overhead that is really tight Do all of this carefully/slowly - don’t just whip it over and back - if your hand is slipping off the broomstick even with the widest grip, or you cant bring your arms over straight and they start bending on you, you have some serious shoulder inflexibility and need to work this hard and get up to speed (or you could just need a longer broomstick too) - again do all of these revolutions controlled and carefully - push into the stretch as you go along toward the 50 revolutions, your chest will be pushing outward and your shoulders rolling back - your shoulders are going to blow up with so much blood its going to be incredibly painful pumpwise.
Do this once a day as many times a week as you can - every time you do it try to move your grip inward (thats the key) - its going to be very hard to do but try your best to move your grip inward for the next 2-4 weeks and your range of motion with shoulders will increase dramatically and any impingement and the majority of other problems should be gone in 2 weeks.
Also try to move your grip in as you are doing the 50 revolutions - start off with a stretching but relatively easy 10 to warm up some, then try to move your grip in even by a centimetre if you can for the next 20 revolutions and then at 30 try to move the grip in another centimetre - really try to push what you can do stretchwise once your warmed up here - trust me this sounds easy but your going to be muttering after you get to your 25th revolution.
Remember the broomstick goes overhead and all the way back to the middle of the back. Arms straight the whole way - and if you cant keep arms straight you have to widen the grip and/or get a longer broomstick (don’t be gripping the broomstick with tights fists - let it roll thru your fingers if it has to as you go up and back). I only hold onto it with my middle and pointer fingers and thumb.
