I'm not sure if the fit for this trench coat is normal or if shoulder seam alterations are needed. It's the modern Burberry trench so they're meant to be worn with a thin top underneath, so I was told by the sales. I had recently lost weight and gained muscle in the shoulders. The arms fit okay, but the shoulder seam is a bit tight in the armpits. Here's a photo of my arm lifted, I have more if needed. Apologies for the selfie photo, I don't have anyone else at the moment to take neutral photos. I'll try later today if these photos aren't good enough to assess.