Nine months pregnant and can do this easily. Like others, I did run out of room and had to swivel around, but I have no doubt I could do 25 paces if I had the room.
Ditto
Sure. In fact I suspect anyone who’s spent any time in marching band could do it without too much trouble.
Easy peasy. And now I know that my apartment is 47 paces long 
I can manage it if I really concentrate on it, but my screwed-up foot and joint pain make it quite a challenge.
Nope. I have bone spurs in my feet and they affect my balance - which I didn’t know until the doctor told me. I just thought I was uncoordinated.
No problem here. I did it both looking down at my feet and looking straight ahead.
I had to corral the cats so they wouldn’t help, but after that, yes.
And I have a crap knee. Obviously the knee doesn’t enter into it.
I knew it wasn’t going to be a challenge, so I tried doing it with my eyes closed. That took two tries.
[shameless bragging] For what it’s worth, the first time I saw some people practicing slacklining in a park, I asked if I could try. It was only a couple of feet off the ground, so I wasn’t particularly worried. I didn’t do too bad. It was a good thing my wife wasn’t there because I was holding my then infant girl during the attempt, which blew the minds of the people there. [/shameless bragging]
I was in my own world growing up, so I did the walking on curbs and all well past the time my childhood friends wouldn’t be caught dead doing something like that.
Not I. I am very duck footed. I have always sort of worried about what will happen if I ever have to take a field sobriety test.
I thought it would be a piece of cake , I stumbled after about 4 steps…my excuse is that I am old. I don’t drink at all so age has to be it.
Yes. We just tried it in my office area - both following a line, then not following a line, watching your feet and not watching your feet.
Clearly we are line-walking superstars
I have balance issues, and won’t even try. I have trouble walking normally without almost falling over.
Got it in one, easy as can be, no problem at all. All those years of yoga and dance classes do pay off.
I can only do it if somebody counts for me. After 10 I am lost. Even barefoot, I get cornfussed after 20.
Hah! I did, and almost failed. I made got credit on the alphabet test, so it turned out ok.
It requires a real effort for me to stand with my feet parallel. My left knee is oddly configured.