Running

I'm guessing it could. I'm constantly running off injuries, and if one foot/leg is stiffer than the other, or better supported by bandages etc. The other one is forced to change the way it works, and/or do more work.

Also.
Arch pain is often experianced when you get new shoes. I'm not sure, but it might be down to the stiffer sole requiring more force to bend.

I think that may be it. One leg/knee is now much more supported than the other. Is it worth me putting the insoles in each shoe or is that more trouble than its worth and I should just leave it in the shoe which actually needs the support?