A relatively new phenomenon in the running world is the emergence of ‘minimalist’ running shoes, often referred to as zero drop running shoes. Essentially these shoes are pretty much level from heel to toe, as opposed to the majority of traditional running shoes which have a built up heel.
The typical running shoe has a heel to toe differential of 12 to 15 millimeters. One school of thought is that this encourages heavy heel striking in runners which could be the cause of many foot problems. The force of impact on the heel can be greater and force over pronation, which is one of the most common problems facing a large number of runners. Over pronation can lead to alignment problems and several types of foot injuries. However, shifting away from typical running shoes will necessitate a modification to your running style as well. It is not a simple switch to make, and must be done gradually with transition minimalist shoes.
A transition minimalist shoe has a heel to toe differential of between 4 to 10 millimeters, and would be the logical path to take towards zero drop shoes. Even this intermediate step will require a gradual phase-in at the risk of sore calf muscles and Achilles tendons. A strength and flexibility program should accommodate this phase as well. The hip flexors and lower legs will be stressed in different ways and an exercise program for these areas is important. This all will be incorporated into the new running style, moving away from heel striking. It is imperative to try short distances first to allow the feet and legs to adapt. An overly aggressive running regiment too quickly is an invitation for a bout with plantar fasciitis.
The full zero drop running shoe has a heel to toe differential of between 0 to 4 millimeters. Pro-minimalist runners and experts argue that this allows the body to run in the most natural position. The feet are able to move without compensating for any shoe form issues. The physics of running suggest that the zero drop shoes, when used properly, do put less stress on the feet, legs, and lower back. However, if the running gait is not properly adapted, and heel striking still occurs, these benefits are not realized. In fact, additional stresses may be introduced as a result.
The possible difficulty of changing your running style may be one reason to shy away from these type of shoes. Another is that zero drop shoes may be ideal for someone with perfect foot mechanics, but not practical for the majority of people who have some structural issues. It wouldn’t make sense to switch to zero drop shoes only to build them back up again with orthotics. Some people dissuade the use of orthotics, but there is no question that they help a lot of runners and athletes. Trying to switch to zero drop shoes when you have a problem foot condition doesn’t usually work.
Regardless, there has been an explosion of zero drop running shoes on the market recently. The long term impact of this type of shoe won’t be understood for a while. It is important to realize that using these shoes requires a fundamental change in running style that will need some adaptation to fully benefit from them.