What Happens to Your Body When You Run or Walk In Shoes That Don't Fit Properly?

If you've ever experienced sore feet, blisters, or bruised toenails caused by wearing poorly fitting running or walking shoes, you know how uncomfortable that can be. In fact, experts estimate that approximately half (or even more in some reports) of the population wears improper footwear, leading to pain, injury, and several foot conditions.

To further complicate matters, finding a well-fitting pair of shoes can be challenging due to unique foot shapes, differences in gait, weight changes, and fluctuations in swelling or water weight. Keep reading to learn more about these issues as well as what experts say can happen if you wear walking or running shoes that don’t fit well.

The Importance of Properly Fitting Shoes

The way that your shoes fit influences the functioning of many parts of your body, including your feet, ankles, knees, hips, lower back, and spine. According to Cara Dobbertin, DPT, a doctor of physical therapy, choosing the proper footwear plays a significant role in injury prevention and enhancing optimal gait mechanics. But wearing ill-fitting shoes can have unfavorable effects on your joints, including your spine, she says.

Properly fitting shoes also provide appropriate shock absorption to help maintain your joint health, says Shari Ritzmann, PT, a physical therapist and owner of FYZICAL Therapy & Balance Centers Westminster and Northglenn. When your shoes fit well, you'll function more effectively with fewer injuries and challenges.

You also will promote the health of your joints, which helps protect your nerves, muscles, and ligaments, adds Ritzmann. "The earlier you start to take care of your feet and body as a whole, the better off you are," Ritzmann adds. Joint health is an ongoing process, and longevity lies in preventing injuries and optimizing function.

Signs Your Shoes Don't Fit Well

Your shoes provide the infrastructure and support your body needs, and they play a critical role in your overall functioning, Ritzmann says. "It’s essential that your shoes provide proper support to be able to uphold the foundation of your joints and muscles in your lower quarter."

For this reason, you should take any immediate discomfort seriously when trying on a pair of shoes, Dobbertin says. This issue can get worse over time and may be an indication that your shoes do not fit well. Both Dobbertin and Ritzman also recommend watching for the following signs that your shoes are ill-fitting.

• Persistent blisters
• Compressed toes
• Shin splints
• Heels dislodging from the shoe while you walk
• Pain in your legs, lower back, or the arches of your feet
• An irregular wear pattern on the soles of your shoes
• Callus formation on the bottom of your feet
• Bunions or hammer toes starting to form

Drawbacks of Running or Walking in Shoes That Don't Fit Properly

Ill-fitting footwear can cause short-term issues like blisters and calluses and long-term complications such as tendon issues, bunion formation, and plantar fasciitis, according to Dobbertin. Slips, falls, and injuries are also a risk of wearing poorly fitting shoes, especially for older adults.

Even exercising in shoes that don’t fit also can cause issues, Ritzmann says. “If you are running or walking in shoes that don’t fit properly, you may develop some serious biomechanical issues in your body such as chronic or progressive issues including foot, knee, or hip pain, worsening of calluses, or even start to see joint deformities." It's essential to wear properly fitted shoes and avoid these complications, she adds.

How to Ensure Your Shoes Fit

When shopping, Dobbertin recommends measuring both feet and picking the larger size. Use your typical socks, ensuring there's space at the toe. You can check the shoe width at its broadest part, and take a short walk to identify any trouble spots.

Knowing your foot type as well as your size also are important to finding the right shoes, Ritzmann says. "Although it is best to have a trained medical professional evaluate your foot type, you can make an educated guess by looking at the wear pattern of the soles of your shoes." If you know you have wide feet, for instance, wide toe box shoes would be a good choice.

Generally, if the soles have a wear pattern toward the inside, your foot will likely be more flexible, and you should look for a more rigid shoe. If the wear pattern is in the middle or outside of your sole, then you tend to have a more rigid foot, and a softer, more cushioned shoe would be the best choice. By selecting your shoes based on this information, you should experience a higher level of comfort for your feet and leg joints, Ritzmann says.

Choosing the Best Type of Shoes for You

Running and walking shoes are designed uniquely, with varying flexibility, cushioning, and support. By choosing the right level in a shoe, you are providing a more supportive foundation for your joints. This is particularly important since your feet are the first point of contact with the surface you stand on.

According to a literature review of footwear types published in the Journal of Sports Science & Medicine, different variables impact how comfortable and suitable running shoes are for particular issues. The study found that softer or thicker midsoles can offer excellent cushioning effects but may also reduce the plantar sensations during landing. Additionally, a wide-toe box and zero-drop design, such as in Alta running shoes, can also help with plantar fasciitis and promote better running form. By encouraging a natural stride, zero-drop running shoes can also strengthen your feet.

Meanwhile, minimalist shoes can help improve running economy and develop the cross-sectional area and stiffness of the Achilles tendon. They may also increase the ankle and metatarsophalangeal joint (toe "knuckle") loading. However, note that the average running shoe is not a minimalist shoe and provides cushioning in various areas.

Research also suggests that running shoes with thick midsoles may prevent running-related pain and injuries, especially for runners prone to foot and ankle issues. Meanwhile, softer or thicker midsoles can provide significant cushioning effects but may also reduce flexibility of the shoe. It's best to keep track of how particular shoes feel and note any issues that arise as you use them.