[theBadCormorant]

This is usually a symptom and not a cause - A problem in or around the spine causes muscles to go into spasm, these muscles shorten and pull the pelvis out of alignment which in turn makes one leg appear a little shorter than the other.

Of course, whilst you have this misalignment the spine is compelled to work and move in an unusual way that can either exasperate your original problem or cause new problems.

The term "Vicious Circle" comes to mind.

I guess the Chiropracticer will straighten you up, and whilst you are in better alignment the body will have more chance to heal, or at least that is the theory.

Before you go you could lie face down on the bed with your feet just protruding over the edge, get your wife to photograph or measure any disparity in your heals (could be half an inch); Repeat after your visit and if there is a notable change you could repeat daily to see how long you stay in better alignment. I used to do this before and after a deep muscle massage, but I would pop back out of alignment in under 12 hours.

EDIT:
One last comment - I also found an hours slow ride on the bike (as in cycling) was as likely to put me into the correct alignment as a deep massage or a bone clicker.