Wheelchair design question

At breakfast the other day, my husband and I saw a man in a wheelchair that had angled wheels. Being engineers, we discussed the possible reasons, and decided that it was a stability feature. The chair got a wider wheelbase without making the whole chair all that much wider, and since the tops of the wheels angled in, it would be as easy to propel as a straight-wheeled chair.

We wondered secondarily if it had to do with maneuverability.

So, anybody able to enlighten us?

Many modern wheel chairs have adjustable camber. Lateral stability is one reason for introducing camber - there are others:

http://www.usatechguide.org/articledisplay.php?artid=23

Racing wheelchairs are built this way … presumably for greater manoevrability (sp?).

As a wheelchair user, I have to say I think it would drive me mad!

Thanks for the links! Very informative.