Calf loosening isn't what cowboys do. Rather it is one of two really easy ways to loosen the foot.
The calf muscles tend to pull the foot flat in the act of trying to propel us forward in a footstep. The foot muscles try to maintain an arch. There is a type of oppositional relationship between the calf muscles and the foot muscles. The more you can loosen the calf muscles the more you loosen the foot muscles.
Stretching is an easy way to stretch the calf muscles. Here are some simple calf stretches. Walkinghealthy.com. http://www.walkinghealthy.com/walkinghealthy/Stretching/CalfStretch.asp
You can even buy a devices to help you stretch. But I like free.
I like to hang off a step. It is simplest of the stretches and very effective. And it resets the stretch receptors so every step you take requires less energy and lessens the impact on your body.
The second approach to foot loosening is a foot roller. You simply roll your foot up and down on the roller. There are a wide variety of foot rollers to choice from. Find one you like.
Resetting your foot muscles to a more relaxed state is easy. And the dividends are many. There are more details in Complete Reflexology for Life. http://www.amazon.com/exec/obidos/ISBN=0756628520/reflexologyreseaA/