Why Running Shoes Wear on the Outside: Understanding the Phenomenon

Have you ever noticed that your running shoes seem to wear down more on the outer edges? It’s a common occurrence, and it’s a sign of how your feet and body interact with the ground when you run. This wear pattern is not necessarily a bad thing, but understanding why it happens can help you choose the right shoes, adjust your running form, and even prevent injuries.

The history of running shoes has seen a massive evolution. Early shoes offered little support, and the way they wore down was often overlooked. It wasn’t until the latter half of the 20th century, with advancements in biomechanics, that we started paying close attention to how shoes wear out. The emphasis shifted from just cushioning to understanding the interaction between the foot, the shoe, and the running surface. This led to the development of different shoe types, from stability to neutral, designed to accommodate various foot and gait patterns. The concept of wear patterns on the outer sole as an indicator of a runner’s mechanics came from this focus on understanding the foot’s interaction during activity. Today, the study of wear patterns is an integral part of how running shoes are designed and chosen, helping athletes achieve better performance and reduce the risk of injuries.

Understanding Supination and Its Impact on Running Shoe Wear

The primary reason for outside wear on running shoes is a natural motion called supination, also sometimes referred to as underpronation. This is when the foot rolls outward when you walk or run. It’s a normal biomechanical movement that happens to everyone to some degree, but some individuals tend to supinate more than others. Understanding this motion is the first step to grasping why the outer soles of our shoes often show more wear. A degree of supination is necessary for efficient push-off, as it helps to stiffen the foot, providing a rigid lever to propel you forward. However, excessive supination can lead to certain areas of the shoe experiencing more stress and friction, resulting in the tell-tale outer edge wear.

Why Does Supination Cause Outside Wear?

When your foot supinates excessively, the outer edge of your foot absorbs more impact during each step. This concentrated pressure on the outer edges of your foot, and by extension your shoe, causes this part of the sole to wear out faster. If we think of the shoe’s sole as a map of the force exerted on it, with higher wear corresponding to a higher force, we see that the outer edge is taking the brunt of the work for supinators. This is the main reason why you see wear on the outside edges of running shoes, a situation which can sometimes be confused with lateral wear running shoes, but these are not quite the same, as we shall see shortly.

Here’s a breakdown:

• Impact Absorption: The outer side of the shoe experiences the initial impact when your foot strikes the ground.
• Uneven Distribution of Force: Because of the outward roll, force isn’t distributed evenly across the sole, leading to higher pressure at the outer edge.
• Friction: As the foot moves through the running gait, the outer sole experiences more friction against the ground.

Factors Contributing to Outside Shoe Wear

While supination is the most prominent factor, several other things can influence how your shoes wear on the outside:

• Foot Type: People with high arches are more likely to supinate. High arches provide less shock absorption and force the outer edge to bear more pressure.
• Running Form: Your gait, including foot strike and stride length, can significantly influence shoe wear patterns. If you are landing on the outside of your foot when running, this will also cause more wear on the outside of the shoe.
• Running Surface: The type of terrain you run on affects shoe wear. Uneven surfaces, like trails or gravel, can accelerate wear on specific areas of the sole. For example, if you’re running on uneven paths, it’s possible for your trail shoes to experience extra stress in specific areas. In fact, you can wear trail running shoes in the gym, but this will not change your wear pattern on the outside. The wear is due to the pronation/supination pattern of the runner.
• Shoe Type: The design and materials of your running shoes play a role in wear patterns. A shoe that doesn’t match your foot type or pronation needs can wear down faster.
• Mileage: The more you run, the faster your shoes will wear out. Even if you have a neutral running style, you’ll still eventually see wear on your shoes.

The Difference Between Lateral Wear and Supination Wear

It’s essential to distinguish between typical wear from supination and what might be considered lateral wear. While both manifest as wear on the outer edge of the shoe, they can arise from different underlying factors. Lateral wear typically indicates a more significant imbalance or a less efficient gait pattern. For instance, a runner who consistently lands far outside their center of gravity will show heavier lateral wear, which isn’t always linked to supination. It’s crucial to observe how and where the wear occurs: supination wear tends to be more evenly distributed along the outer edge of the sole, while lateral wear might be more concentrated at certain points, and can happen even to those who wear shoes football players wear when they’re doing athletic training.

“Understanding your individual wear patterns is key to making informed choices about your running shoes,” states Dr. Emily Carter, a biomechanics expert at the National Sports Research Institute. “It allows for personalized recommendations that can enhance performance and prevent injuries.”

What to Do About Outside Wear on Your Running Shoes

Seeing wear on the outside of your running shoes doesn’t necessarily mean you need to panic, but it’s important to address it:

1. Assess Your Foot Type: Determine if you have high arches, which can contribute to supination. A podiatrist or running shoe specialist can help with this.
2. Evaluate Your Running Form: Look for a running coach or experienced runner who can assess your gait and provide feedback on improving your form.
3. Consider Orthotics: If you have excessive supination, orthotics can provide the support needed to stabilize your foot and improve your gait.
4. Choose Appropriate Shoes: Opt for shoes that match your foot type and pronation. You may find that a neutral shoe is all that’s needed. If you find that you are over-supinating, a stability shoe could help guide your foot through a better range of motion.
5. Rotate Your Shoes: Don’t just wear one pair of running shoes. Rotating two or three pairs can help distribute wear and tear.
6. Replace Shoes Regularly: Running shoes lose their cushioning and support over time, which can increase stress on your feet and joints. Monitor for excessive wear, and don’t run in a shoe that has worn down too much.

The Importance of Shoe Rotation

Rotating your running shoes is essential not only for extending their lifespan but also for reducing the risk of injuries. Running in the same shoes every day doesn’t give the cushioning time to recover, and it can increase pressure on your joints. When you do rotate your shoes, ensure that you choose them according to the type of activity you’ll be performing. You would not want to wear basketball shoes to the gym if you’ll be doing a run or an activity that needs a flat sole.

Dr. Michael Thompson, a sports medicine physician, advises, “Shoe rotation is not just about extending the life of your shoes; it’s about safeguarding your body against overuse injuries. The cushioning in running shoes takes a beating, and rotating helps them rebound.”

Addressing Common Concerns and Misconceptions

Many runners worry about the outer edge wear and may make incorrect assumptions about its causes. Let’s clarify some common concerns:

• Not an Immediate Problem: Moderate wear on the outer edge of your running shoes is often normal, not necessarily a sign of an issue needing immediate medical attention.
• Shoe Design: Shoes that wear on the outside are not always bad. Often, this wear pattern simply reflects your body’s natural mechanics during running.
• Not a Sign of Poor Running: Most wear is just a result of how our bodies were made to run. However, excessive or uneven wear could be indicative of an issue with form or choice of shoe.
• Shoe Quality: While higher quality shoes may wear down more slowly, they will still show some wear on the outside for most runners, as this is often a result of our natural biomechanics.

Conclusion

The phenomenon of running shoes wearing on the outside is very common, and in many cases normal, due to natural supination during running. Understanding your own foot type, running form, and the potential influence of external factors can help you make the best shoe choices, reducing the risk of injury and improving your running experience. Remember, the wear patterns on your shoes are a great way to understand how your body interacts with the ground when you run. By observing these patterns and acting on them, you can make sure that your footwear is working with you, not against you.

Related Resources

• American Podiatric Medical Association: https://www.apma.org/
• Running Shoe Review Websites: RunRepeat, Road Runner Sports
• Biomechanics Research Institutes: Numerous universities worldwide conduct studies on human movement and athletic performance

Frequently Asked Questions (FAQ)

1. Is outside wear on running shoes always a sign of supination? While supination is the most common reason, it is not the only one. Running surface, gait, and other external factors can also influence wear patterns.

2. Can I correct supination? Yes, to a certain extent. A combination of choosing the right shoes, using orthotics, and adjusting your running form can help minimize the impact of supination.

3. Should I switch to stability shoes if my running shoes wear on the outside? Not necessarily. If the wear is minimal and you do not experience pain or discomfort, you might just be naturally supinating. However, if you feel that you are over-supinating, a stability shoe might help guide your feet through the correct motion.

4. How often should I replace my running shoes? It’s generally recommended to replace running shoes every 300-500 miles, but this can vary based on the shoe, your weight, and running surface. It’s best to monitor for wear, and change them out once you see that they are no longer providing the cushion and support that you need.

5. Do different types of running shoes wear differently? Absolutely. Different types of shoes are designed to accommodate various foot types and pronation styles. The type of shoe you choose will affect how it wears.

6. Can running on a treadmill impact the wear of my shoes? Yes, running on a treadmill can impact the wear of your shoes. While it is typically a more consistent surface than running outside, it still produces wear, and some runners’ wear patterns can vary when going from a treadmill to running outdoors.

7. Can indoor running shoes be worn outside? While you can wear indoor football shoes outside, their soles are not designed for the rigors of outdoor surfaces and they may wear down quickly.

8. Is it bad if my running shoes wear unevenly? Uneven wear could be an indicator of an issue, however, it’s vital to evaluate where the wear is concentrated, and if you have excessive supination, seeing more wear on the outside edges of your shoes is quite normal.

9. Does shoe wear affect performance? Yes, if your shoes are worn down excessively, they can negatively affect your performance, and may also increase your risk of injury.