If they gave you a loaner they've either changed policy or I had the ignorant screener. When I messed up my knee 7 years ago I used a wood cane for a while. They took it away to run it through the x-ray, and I just had to hobble through on my own. Of course I'd had to take off my shoes so it's slippery with just socks on. I put my hand on the detector for balance and oh my goodness you'd think I had insulted his mother from the tongue-lashing I got. Does placing ones hand on the upright portion somehow render the device useless? If so he can certainly tell me that; I don't know how the dang thing works. He doesn't have to scold me like I'm a five-year-old.
Afterwards I'm trying to collect my pocket items, belt, shoes, cane, hat, carry-on bag and was apparently not moving quickly enough; got another earful about holding up people behind me. ME holding up the line? Really? After the wait I just went through? For once in my life I smartly bit my tongue and shut up. They'd have arrested me if I'd said what I was thinking.