Can I prune old grape vines to get canes closer to base?
 

I inherited a bunch of grape vines last year. I know nothing about grapes,
but have tried to learn about pruning from the internet.

Our plants have thick wood at the base; I don't know how old they are, but
the trunks are about two inches across; maybe about five inches in diameter.

I tried pruning them yesterday, and discovered that the trucks go a
LOOONNNNG way before sending out canes. Some of the trunks are bent and
curled, often sending out canes as much as three feet from where the trunk
comes out of the ground. All the info I have seen assumes a short trunk
with canes coming out just a few inches above the ground, but on these
plants you have to travel quite a bit to get to new growth. I suspect the
plants were not trained well earlier, and the pruning took place farther and
farther from the base each year.

My question is, is there any way to sort of train these back to getting
growth closer to the base? It seems like there is a lot of wasted space
now, as the trunks go several feet out of the ground before any growth. The
trunks are heavy and lean on the wires. All websites I have looked at give
instructions for pruning based on a plant that has been trained well to grow
from the base. I can't seem to find any info on pruning grapes that have
such long trunks.

Any information or web sites would be greatly appreciated.
--Suzanne