An entertaining topological party trick that I have seen performed is to turn your pants inside-out while having your feet tied together by a piece of string. For a demonstration, check out this [video](http://www.youtube.com/watch?v=O70156EDGuY). 


I have heard some testimonial evidence that it is also possible to turn your pants *backwards*, again with the constraint of having your feet tied together. This second claim seems pretty dubious to me.


**Question.** Is it indeed possible to turn your pants backwards, while having your feet tied together by a piece of string? A set of instructions or a video demonstration would suffice for a yes answer. A precise mathematical formulation of the problem together with a proof of impossibility would suffice for a no answer.



Turning pants inside-out (or backwards) while tied together
I think that the answer is no, by consideration of [linking numbers.](http://en.wikipedia.org/wiki/Linking_number)
First simplify the human body plus cord joining the ankles to a circle, and 
assign it an orientation. Also assign an orientation to each pant cuff.
This can be done, e.g., so that each cuff has linking number +1 with the
"body" (in which case the two cuffs are oppositely oriented). 


Now suppose that there is an isotopy of the pants that turns them backwards.
This means the left cuff is now on the right ankle and vice versa. But this
also reverses the linking numbers, which is impossible.


