What's the Name of his Other Leg?

I was at the gym the other day, at around lunchtime. Apparently this is the time of day when it's most quiet, so a lot of the gym staff do their own workouts then. I saw my assigned personal trainer standing at the water fountain. It seemed like there was something strange about one of his legs. It took me a minute or two to figure it out. Trust ME to get assigned the personal trainer who...

...has a titanium leg.

I find myself wanting to ask him if it's name is "Smith."*

* Watched Mary Poppins lately?