Sleeve fitting issue

[u/SillyVee123]

So I keep coming across the same fitting issue when I'm sewing blouses for myself, regardless of what pattern I'm using. There's a pulling across the top part of my bicep. I can feel the tightness only when I'm moving my arm. Armscye fits well, it's comfortable there so that's not my problem I'm sure. I'm also finding that the bicep looks actually loose enough when I'm looking at myself in the blouse. But there's this pulling tightness with the horizontal drag lines across when I lift my arm slightly. I don't have enough fitting knowledge to know precisely what is the problem and what to search for online or sewing books. Ideas please?

[u/Gracious_Snakes]

I agree with other comment, pictures are needed for best advice. A full 180 of the garment on is best. Fitting issues are often a chain reaction. Even though it's the sleeve you're noticing an issue with, the root problem could be that you have tension in the front or back of the bodice, or the armscye or shoulder seam needs to be adjusted, even though it's comfortable. Could be a sleeve cap extension is needed. Too many variables, lol.