1998 Honda Civic Shaking 45 to 55 mph

My Civic shakes when I'm going between 45 and 55 mph. If I put it in neutral and take my foot off the accelerator, it still shakes. The car isn't pulling to the left or right so I don't think it's alignment. When I push down on the fenders, it doesn't bounce,so I don't want to spend $1200 on struts for a car that's only worth $3000 and find out that wasn't it. Any ideas?

Mark