Is there something I can eat that will loosen or lubricate tight muscles?

You would have to figure out why you have tight muscles. Over work, too much exercise, stress, etc...
You can soak in a tub and learn to relax.

Do you get arthritis type pain? For some people eating night shade plants -egg plant, onions, peppers, tomatoes, potatoes,

Can get stiffness from those foods.

Nightshade (http://www.archure.net/salus/nightshade.html)

Thank you for your answer. It was a simple tightness question. Dayneordrea

Bananas. They have potassium which helps relax muscles.