Not all running shoes are made alike. Considerations are taken for different foot types. Matching the right shoe for the right foot is the best you can do to give your feet proper care. Injuries happen sometimes because of the wrong shoe. Unless you are using the shoes for merely walking, you have to make sure that the pair that is given to you (second hand) fits to your type of feet before you consider the pair for running.
Understanding pronation and determining your foot type
The rolling of your foot from your heel to your toe is the pronation. Some overpronate (low arch/flat feet), some underpronate (high arch) and others have neutral pronation (neutral arch). The easiest way to determine how you pronate is to do the wet test. With your wet feet (not dripping), step on a paper bag or manila paper and draw along the outline if you want to keep it longer.
Overpronators have the least curve on the inside of the foot. The entire foot is imprinted. Neutral pronators have slight curve with the inside almost at the center of the foot. The underpronators have a thin imprint at the outside of the foot.
The kind of shoe for your foot type
Overpronators should choose shoes having a straight shape to give maximum support and with motion control to prevent feet too run too far. Motion-controlled shoes are the most rigid and control-oriented shoes.
Neutral pronators should choose shoes that are semi-curved. Stability shoes are perfect offering a good blend of durability, cushioning and medial support. The semi-curve does not control as much as the motion-control kind of shoes.
Underpronators should choose shoes that are curved and cushioned to allow feet to roll inward and absorb the shock. The curve encourage the foot motion. Such shoes have the softest midsole but with the least medial support.
If you are a serious runner (like a racer), you should also have a high performance pair. They are lighter, lower to the ground, semi-curve to curved and minimal cushioning and stability features which makes it inappropriate for most recreational runners.
Getting the proper fit
Choose a store that specializes in running shoes. The person to assist you can help you figure out what fits perfectly. Do your shopping in the late afternoon when your feet are at its largest. Have your preferred socks ready and make sure to measure both feet because one is slightly bigger than the other. You will be asked several questions by the sales person to help you get what you need. The perfect fit is snug but not tight. Have room for your toes the width of your thumb. Feel the shoes in action with some walking, jogging and bouncing. Some stores let you use their treadmill.
Buying a pair of running shoes is a serious matter if you want your feet to have the most comfort they can have. Knowing your pronation is the key to start getting the perfect pair.