I dunno, depends on what you want to accomplish... Few years ago I thought I was staring downward too much while walking (Don’t drive, so I walk a lot), putting my head up more I was more aware of further surroundings and noticed more things, but found I didn't have as much time mental problem-solving while commuting as I had previously.
Maybe if I wasn’t so happy an introvert I'd do it more, but I prefer to be in my mind than noticing the mostly oblivious community.
On a related note, I once got a reading injury - I had a 45 min walk to work, and so tried reading a book on the walk. After a week of this, I had hurt my neck - your neck isn't really made for bobbing your head in a reading posture while walking :)
Also relatedly, I've experimented holding my phone higher than normal while reading from it, at almost eye-level. But I can't get myself into the consistent habit.
The ramifications physically of bad posture affect you regardless of any of this. If you really want to cur out the outside world more while walking, wear a brimmed hat low on your face but keep your head up.
Heh, yeah. But you don't have to pop your veins out of your neck. And if you have a skip in your step and/or wear some quirky colorful clothing, people won't see you as aggressive just for having good posture and a low hat.
Maybe if I wasn’t so happy an introvert I'd do it more, but I prefer to be in my mind than noticing the mostly oblivious community.