do you have a rounded back(kyphosis) and that is affecting your health and confidence? do you want to develop your upper back muscles but do not want to lift heavy dumbbells? do you want to build stability in your shoulder girdle?
Y-Press is the answer to all of them it works on multiple muscles and demands strength and stability from all of them without the need to lift heavy weights, even professional bodybuilders and even powerlifters cannot do this exercise with dumbbells heavier than what they warm up with for shoulder side raise!!
talking of warm-up, make sure you do it before doing this exercise since any exercise that demands high stability from the joints, needs to be ready for it. as mentioned in the video, do this exercise with shoulder press instruction and do not bring your arms on top of your head but like the letter V.
make sure your elbow is not to your side and bring it a little bit forward and also, do not bring it all the way down to your torso. around 90 degrees compared to your torso is fine. do not move your head intentionally as well, but do not force it to be steady either.
it might move a little bit because upper traps are involved and they extend the neck as well but make sure you do not initiate it.
make sure your back is flat, your hands are squeezing hard and your torso is parallel to the ground. if flexibility is the issue, stretch your back thigh muscles(hamstring muscle) and your inner thigh muscles(adductor muscles).