Is it possible to convert swivel wheels?

Well today we went for a walk as it was cloudy and they weren't calling for rain until later this afternoon...then we stopped at the park on the way home and about five minutes later the thunder started. We threw all the sand toys into their bags and I loaded all 5 kids into my 6 seater Bye Bye Buggy and I ran with them all the way home...we just avoided the worst of the rain. The problem is, when I try to run with this stroller, the front wheels often start swivelling and shaking and I have to stop and walk. It got me thinking about jogging strollers and how their wheels don't swivel...and Runabouts which also don't swivel...and I was wondering if anyone has ever heard of a way to lock wheels to keep them from swivelling if they don't come with a locking mechanism? This is likely the reason I can't push it in the snow too...the wheels are really big and the tires are fat...it's the swivelling that's the problem. Any ideas???

I would check with a bike shop, they would know and might be able to MyGyver something for you.

I would get something that is not permanent though as the swivel is useful for more maneuverability on normal terrain.