A Shoe for Every Foot

Imagine peeking into a runners closet! Will you find an orderly array of training shoes and racing flats or a heap of old favorites, discarded relics and mismatched choices. With so many companies and shoes to choose from our choices couldn’t be better or more difficult.

When shopping for a new racing or training shoe what do you look at first? The price, the color, the shape, the cushioning, the outsole, the lug pattern, the size, the brand, your doctor’s list, or its weight. Yes, all of these may represent important factors leading to the successful selection of your next running shoe but didn’t you forget one very important factor, your foot. The running shoe is an extension of our foot, a mismatch can lead to the development of a wide array of over use injuries or uncomfortable maladies.

The running shoe serves as a structural and functional extension of our foot. Chosen wisely it can impose a beneficial influence on our running, improperly chosen the shoe can amplify anatomical and functional flaws and there by increase the risk of overuse injuries. To better understand the role our running shoes play we must first examine the basic shape and movement characteristics of the foot in motion. Several methods have been devised to examine or categorize the anatomical shape of the foot; the most widely applied method subdivides feet by the height of the arch, including, high arched, normal arched and low and flat arched feet. Classifying the motion of the foot during running is more difficult. Again several systems have been devised, the most widely applied relies upon the angular relationship of the heel to the supporting surface during the mid stance phase of running gait. This classification system creates four categories which include, under pronation, neutral, over pronation and severe over pronation. The combination of these two basic factors can assist you in your search for a new running shoe. (see table 1).

The anatomy of the foot is well suited to motion, it is more poorly suited to static upright stance. The foot clearly serves as a primary shock absorber at heel contact. The robust heel with a highly developed plantar fat pad and spongeous internal structure can absorb a significant portion of the forces imposed upon the supporting extremity at heel contact. Shock absorption is further enhanced by the internal motion of the heel during initial heel contact. This internal motion is referred to as pronation, and results in a flexible and pronated foot. The remaining forces of impact are absorbed by other bones, joints, and soft tissues of the supporting extremity and torso. At the end of heel contact, the forces of running are shifted to the ball-of-the-foot. The foot now begins a lengthy process of reversing the flexible and pronated position of the foot to that of a structure with internal rigidity and stability. This reversal is referred to as supination. The supinating foot is more effective at converting the efforts of the large calf and hamstring muscles into forward motion. Supination of the foot begins during midstance and continues until the foot contacts the ground again at heel contact. Thus, the events of pronation and supination are necessary for normal running gait.

As previously described, we will describe the shape of the foot by the nature of the arch, its height is not easily determined by casual observations. To best visualize the characteristic shape of your arch, moisten the sole of the foot with water and stand on a sheet of paper. The outline or imprint will generally depict the pattern of weight bearing and there by the basic height of your arch. The higher your arch the less contact your foot will have with the ground alternately, the more contact your foot has with the ground the lower the arch. This information is important as the field of available running shoes can be initially narrowed by shoe shape or last.

Variations to the pattern of normal running gait frequently occur. They can range from minor flaws to severe periods of lower extremity instability. Irregular terrain, canted roads, abnormal anatomy, neuromuscular and connective tissue disorders, improper running shoes, worn out running shoes and poorly fit orthotics can all alter the characteristics of your running gait. Like wise, improvements to an abnormal gait pattern can be achieved by careful shoe selection, well fit orthotics and careful attention to training. The characteristics of normal and abnormal gait can be best observed on video gait analysis. Identifying your pattern of running gait or function represents the second factor critical to the selection of an appropriate running shoe.

Previously, four categories of foot function were introduced, including under pronation, neutral, over pronation and severe over pronation. These categories have been widely discussed in running circles. Under pronation represents the inability of the heel to achieve an everted (or pronated) position during heel contact or during the opening period of midstance in running gait. This foot appears to remain supinated through out the stance phase of the running gait. Shoes often wear rapidly along the outer (lateral) aspect of the shoe, with little or no wear along the inner (medial) aspect of the shoe. The heel counter and midsole are frequently broken down laterally and the heel counter will remain in an inverted (supinated) position. Neutral foot function is common; the heel everts (pronates) during heel contact and into the midstance phase of running gait. The neutral foot will reverse this motion by inversion (supination) of the foot during midstance and heel off phases of running gait. Shoes wear at the outer (lateral) heel, center near the ball-of-the-foot and in line with the big toe. Over pronation occurs when the heel everts (pronates) during heel contact and continues to progress well beyond the midpoint of the midstance phase of gait. For this foot resupination of the foot does occur but not until the very end of the midstance phase of gait or as heel off begins. Shoe wear patterns demonstrate increased outsole wear at the outer (lateral) heel, inner (medial) side of the ball-of-the-foot and on the inner (medial) side of the big toe. Severe over pronation is rare, but when present will result in rapid evertion (pronation) of the heel at heel contact. The heel will remain visibly everted (pronated) throughout the stance phase of gait. This foot will resupinate only during the swing phase of running gait as the trailing leg is brought forward in preparation for the next stance phase. Wear patterns to the shoes of severe over pronators demonstrate accelerated outer (lateral) heel wear, increased medial only wear at the ball-of-the-foot and medial to the big toe. Heel counters and midsole are usually crushed over medially and left in an everted (pronated) position.

Prolonged pronation and premature initiation of supination are associated with overuse injuries. Recognizing which pattern best depicts your foot will provide you and the shoe store staff with another critical piece to fit in the running shoe puzzle. In general, when selecting a new shoe start with a last that best conforms to your foot. High arched feet generally respond best to curved and split lasted shoes. Normal arched feet will do fine in semi curved or semi straight and split or combination lasted shoes. The flat or low arched foot will do best in a semi straight or semi curved or straight and a combination or board last shoe. These trends are meant to represent a starting point, to further narrow down the field of running shoe choices introduce the characteristics of your running gait (see table 1).

By following these guidelines and following the suggestions in table 1 you have a good chance of choosing a good running shoe for yourself. Your running shoe salesperson can be instrumental as they help you pick a couple of shoes to compare. Happy shopping and running!

 Material © Institute for Physical & Sports Therapy
Used by permission