The wonderful thing about magic in the Dresdenverse is that you are only limited by what you believe you can do. Traditionally magic 'circles' are envisioned as spheres. If your mage views the containment field of a magic circle as a cylinder then you're good. If not, Dresden has been known to shape his shield magic effects to improve their effect, a similar effect could encompass a person.
Movement is a much trickier thing to deal with. I'd say if the magic circle was powered by kinetic energy like Harry's rings then the circle could be empowered with every movement to provide a relatively constant effect.
If that doesn't work the players could resort to the same sort of tactics that Doctor Who used to fight The Silence in the season opener last week. For those of you not familiar with the show on BBC America www.doctorwho.bbcamerica.com
Specifically his companions started tallying on their arms any time they spoke to hom so that when they turned away they would see the tally and realize they had seen one of The Silence. Later they implanted digital recorders into their palm so they could leave themselves a voice message they'd be able to remember...it would light up to let them know a message had been left for them.