In only 5 years, some of the corners of my laminant wood floor are swelling upwards. Could our office chairs be causing the movement or the foamy under-layment?

More likely that the flooring was installed to tightly. Laminate flooring requires a 1/4" space between the flooring and the wall (usually under the baseboard) to allow for expansion.

I think that could be it. Do you have a plastic mat un your office chairs. That should help.