Theoretically, I love the minimalist footwear concept. Practically, however, these shoes are designed for a very small percentage of runners who use them. Having performed many running analyses, my clinical experience tells me that there is slow and steady process to become an injury-free minimalist runner. When runners try to shorten or circumvent this process, troubles occur.
Every week I deal with runners who come to me with pain they receive from running. One of the first questions I always ask is, “Which shoes do you use?”
An innocuous question, but one that is frequently followed with a surprising answer.
Serious runners generally do not experience the quandary of which shoes to use. They usually have a good idea what is out there, mixed with their style of running and the engineered factors in the shoe they are looking for. Most others choose a shoe based on the look and style, rather than the substance. For example, they may choose a shoe that looks great with the new style of shoes in the market, but are not true running shoes. They may even be cross-trainers. Or they may choose a shoe that prevents pronation when they have a neutral foot. These are the runners who are setting themselves up for a future injury due to the repetitive nature of the activity.
Many runners who try minimalist style shoes—or even running barefoot—experience a series of injuries due to a too-fast transition from full-soled running shoes to barefoot or minimalist running. Our heel contains a fat pad that is there for shock absorption when we heel strike. Normally the shoe will absorb this shock, but those who have attempted a heel strike on pavement know the pain that comes from 4-8 times your body weight on your heel—multiplied by 10,000 steps! This initial shock is then transferred to the ankle, knee, hip and back where the pounding on these joints stresses them to the point where you can’t move the next day.
Stress fractures are another injury I see frequently with runners who quickly convert to minimalism. With a stress fracture there is a microscopic fracture that occurs in the bones of the foot. The repetitive nature of running does not allow the fracture to heal and a deep pain in the foot develops. These types of fractures are very difficult to find on an X-ray (oftentimes an MRI or bone scan is needed to diagnose the fracture) and the runner is forced to stop for 6 to 8 weeks, or, in some cases, even longer.
Another common injury is plantar fasciitis. This is a number of strong collagen bands that extend from the bottom of the heel to the heads of the metatarsal bones. Without the arch support, a bone called the Navicular can drop and remain displaced, thereby stretching the plantar fascia. Micro-tears occur in the fascia, which heal when you are sleeping. When a person is experiencing plantar fasciitis the first steps in the morning are excruciating, but usually resolve after 10-20 minutes. This is actually the problem. The micro-tears have started to heal when at rest, but those first steps in the morning tear them apart again, thus causing the pain. This becomes a chronic condition and plantar fascia ends up in a constant state of inflammation accompanied by pain with each and every step.
The most common muscle ailment I see in patients who quickly jump to barefoot or minimalist running is with the calf muscles. There are two muscles of the calf, the gastrocnemius and the soleus. The gastrocnemius is the superficial muscle the lower leg uses when the knee is extended or straight. The soleus is the muscle used when the knee is flexed or bent. The soleus is the larger muscle that takes the brunt of the force and requires slow and steady training in order to run with a minimalist shoe. The soleus is utilized more intensely since the midfoot strike requires the knees to be flexed to absorb the shock of body weight and gravity. The pain one experiences is deep and close to the bone and is difficult to stretch. Some of my patients have remarked that they could not walk for three days after running because the muscle was so tight and they could not flex their ankle to climb stairs or rise from a seated position.
So with all of these potential injuries, who is the minimalist or barefoot runner?
The answer is not always that easy to define. Truthfully, only about 10% of the runners out there have a “runner’s body,” the rest are round pegs trying to hammer themselves into a square hole. A runner’s body is lean, light and long. These appropriate runners are experienced, have good to excellent technique with a midfoot or forefoot strike, a combination of muscle strength balanced with good range of joint motion, proper foot mechanics and an even stride. Most importantly, a minimalist runner should slowly progress into the new running style using a walk-to-run ratio that steadily trains their muscles to handle new loads. Slow and steady is the technique that will minimize the risk of injury to the minimalist runner.
By Dr. Andrew Pritkin
Dr. Andrew Pritikin is a Doctor of Physical Therapy and Clinical Director of the Bauerfeind Performance Center in Santa Monica, California. He has extensive experience treating professional, Olympic and collegiate athletes, and speaks frequently on healthy aging and sustainable activity. The Bauerfeind Performance Center provides advanced sports therapy, sports injury treatment and orthopedic treatment for active clients in the Los Angeles area.