My wife is borrowing her mom's adult trike, to make it easier to walk the dogs with her bad ankle. It looks strange, but it works--She takes the dogs through the alley to the bike path while riding the trike, from there to the river where they can go off leash.
The trike is a Walmart special, a Worksman Trifecta. I'm not impressed. It started grinding, and when I investigated, I found that one of the bearings has chewed itself, because the rear axle shifted. There's nothing to center the axle except the chain and side loading of the cheap bearings--If I remember right, this type of bearing isn't designed to handle side loads.
I was able to swap the chewed bearing with the one in the drive wheel, which is used as a bushing instead of a bearing. Don't know what I can do to prevent this from happening again.
Walmart.com also sells a Schwinn adult trike for a few dollars more. I haven't seen it in person. Schwinn is nowhere near the brand it was even 10 years ago, but I'd get it over the Worksman just based on the internet pictures.
Adult trikes are surprisingly hard to get used to for someone who rides a bicycle. When you steer a bike (or motorcycle) you countersteer--First steer away from the direction you want to go. This doesn't work on a trike. To make matters worse, the trikes at work have one drive wheel in the back, and the coaster brake is on the drive wheel. The first time I rode one was at work--I wound up crashing into an electric flatbed truck.