Pronation: Friend or Foe?
Pronation gets a bad name in the running world. I’ve seen many patients in the clinic who come in and appear shameful that they “overpronate”, casting their eyes downward and away, as if it were some sort of egregious act. However, pronation is a normal (and very important) aspect of the walking and running gait cycle.
So, welcome to pronation nation (don’t worry, I’m not going to try and trademark that). Let’s explain what it is, why it is needed, and what to do if it really is a problem.
What is pronation?
Pronation refers to the multi-axial movement that allows the foot to adapt to whatever terrain we happen to be walking (or running ) over. It involves the talus, calcaneus, navicular, and the metatarsals. Therefore, all three parts of the foot: the rearfoot, midfoot, and forefoot participate in this complex movement. When pronation is “normal”, it occurs during midstance of the gait cycle, as your body is progressing over the planted foot. The foot then transitions into supination as it pushes off and propels you forward. This is a very important transition, because the foot is more flexible in pronation and rigid in supination. The rigidity of the foot at the end of the gait cycle is crucial for forward progress-- think of the difference between climbing a normal ladder vs. a rope ladder.
Visually, we see pronation as an inward movement of the foot and collapse of the arch. The degree to which one pronates depends on multiple factors, including bony structure, muscle/tendon strength, movement habits, footwear, and activity history. For example, your foot will behave differently if you walked barefoot a lot as a child vs. in shoes. A soccer player will develop different patterns than a swimmer. Genetic factors predetermine arch height, and often are affected by development.
Friend or Foe?
Pronation is an important part of the running and walking, because it allows us to adapt to the terrain and absorb force. However, if it occurs too quickly, too long, or in the wrong part of the gait cycle, this position of the foot and ankle can increase risk of injury.
Rapid, uncontrolled pronation places a lot of stress on the posterior tibialis tendon and plantar fascia, because this places a “twisting” load on these structures, which is unfavorable to how the tissues are designed to handle stress. Additionally, the rest of the leg rotates to accommodate for the foot position as well, and can cause knee and hip pain over time.
Late pronation, or pronation during the push off phase, is a common pattern seen in runners with Achilles issues. Not only does this hinder how much power can be generated off the ground, but also places strain on the Achilles tendon and overloads the calf.
What can we do about it?
Strengthening the feet and lower leg is a great first line of defense against injuries caused by improper pronation. This includes arch and posterior tibialis strengthening, balance exercises, and variations of heel raises. The posterior tibialis is the muscle that is responsible for the control of pronation, so making sure that it is functioning properly in single leg stance is crucial. Additionally, strengthening the hips so that they can work together with the foot is important as well. Strength and endurance of the hip rotators help with foot placement and makes it easier for the lower leg to control pronation.
Switching to stability shoes, trying out inserts, or orthotics should be taken on a case by case basis. People with certain foot types or medical conditions can benefit from altering foot position in this way, both temporarily during injury or long term to stay healthy. The strengthening work is beneficial and non-negotiable: just because you get a little help from your shoes doesn't let you off the hook!
Fear not: In the next post of this series, we'll go over some exercises to make pronation your friend and not your foe!
Keep going, you got this!
Kacy Seynders, PT DPT