Shoe Inserts, Insoles, Simply Feet.
Some athletes need support and an insert for the running shoe if they are prone to overuse injuries, or have back,knee or foot pain. Running insoles are ideal for some athletes suffering from these conditions.
About once a year i goto a sports shop that sell great trainers and they get you on a treadmill and make a video recording of your running style to see if you have any adverse pronation or bad alignment. A friend of mine who i sometimes run with uses arch supports in his shoe and he swears by them. Simply feet provide runners with a good variety of insoles. If your suffering from back pain when you run then this can be an indicator to unbalanced running style and this may help.