If you are suffering from muscle soreness, have a sprain or bruise, try dropping a few cups of Epsom salt into a drawn hot bath. If you are too manly for a bath, disolve the salt into large bowl with hot water and then soak an appropriate size towel to wrap/cover the injured area.
This a is a basic, old school remedy. My grandmother was never without a 5 pound bag in the house. It costs less than five US dollars for a bag. You can pick it up at any drug store or major chain like Wal mart.
It is also great for your plant water. Just add a couple of tablespoons before watering your plants.