Written by Sean Rimmer PT, DPT, OCS for the Winter 2023 edition of our Trail Times newsletter. Sean is an avid trail runner and physical therapist living in Colorado Springs, CO, where he is the owner at Run Potential which focuses on rehab and performance training for runners.
Have you ever dealt with a nagging pain in the foot or ankle during your runs? Do you find yourself dealing with pain and stiffness in your feet the first thing after getting out of bed in the morning? If your answer is yes to either or both questions, you are not alone. Pain and stiffness in this region are common in runners, but that doesn’t mean it has to be the status quo.
When was the last time you took a good look at your feet? Better yet, when was the last time you were able to control the movement of your toes independently of your foot, perform single leg balance on a stable foot without significant wobbling, or slowly and deliberately control your foot’s arch rising and lowering? If you are unsure or unable to perform these innate human functions, there is some low hanging fruit to address. Our foot works as our foundation, and if your foot lacks the controlled mobility and/or stability, you are at a higher risk for injury to occur either locally or up the kinetic chain while running. Remember, running is merely alternating single leg hops under repetitive load, and each time your foot hits the ground it needs the dynamic mobility and stability to perform its function.
In this article, I will provide a brief education on the anatomy and biomechanics regarding the foot and ankle. I will then shed some light on areas to assess your foot and ankle mobility and stability, so you can become a more resilient runner.
The human foot is a complex anatomical region that is well designed for both stability and mobility. The human foot includes 28 bones, 30 joints, and a multitude of soft tissue structures including muscles, tendons, and ligaments that help control the movement within the joints. The foot is further divided into 3 major portions:
- The rear foot including the talus and calcaneus bones
- The mid foot including the cuboid, navicular, and 3 cuneiform bones
- The fore foot including 5 metatarsal bones, 14 phalanges, and 2 sesamoid bones
Each division of the foot has an important role in the function of the foot, yet no single region acts in isolation. It is vital that all regions of the foot have the appropriate amount of mobility and stability for the foot to have healthy function.
The foot’s major role in running is to store energy and release it for propulsion under a short period of time. The energy storage component of the foot and ankle occurs during pronation, or the loading response in our running gait. Pronation has previously gotten a “bad rap” within the running community due to the initial thought that pronation leads to pain and problems; but, there is no literature to support this notion. Pronation consists of the following major movements within the foot and ankle: ankle dorsiflexion, rear foot eversion, and forefoot abduction. This combination of movement allows a majority of our soft tissue surrounding the foot and ankle to purposefully lengthen allowing our arch to increase its tension. This tension created in the soft tissues on the underside of our foot allows energy to be stored so it can then transition into the release of energy for propulsion, known as supination.
Supination is the position of the foot and ankle that is more rigid and provides a stable lever for propulsion. This turns out to be the push off phase in running. Supination consists of the following major movements within the foot and ankle: Ankle plantar flexion, rearfoot inversion, and forefoot adduction. This combination of movements create a bony lock within the foot providing stability to transfer energy from the foot through the rest of the kinetic chain.
Both pronation and supination occur fluidly and cyclically in running. I like to give the example of jumping on a trampoline. When we initially jump on a trampoline, the trampoline moves down to absorb the weight of the person. When this happens, the trampoline creates tension in a lengthened state, think of this as pronation. The trampoline then recoils, releasing the stored energy that moves the person into the air, similar to supination.
When our feet are strong, supple, and coordinated, they can tolerate the mechanical load of running without issue. However, if our feet are lacking the mobility, stability, or coordination (timing of muscles activating) they need for running, then there is a greater potential for the onset of pain or even injury. The risk for pain or injury may happen in an area of the foot and/or ankle, but could also occur up the kinetic chain.
When it comes to foot and ankle mobility during running, it’s imperative for there to be adequate mobility within the following 3 joint motions:
- Big toe extensions
- Mid foot rotation
- Ankle dorsiflexion
Foot Diagram
Big toe extension allows for our foot to roll off of the big toe during supination, mid-foot rotation allows for our foot to transition from pronation to supination, and ankle dorsiflexion allows our calf-achilles complex to store energy so it can be released during the propulsion phase of running. These 3 motions are important for loading response, terminal stance, and push off. If any of these 3 joint motions are significantly limited, a compensation pattern often occurs within the kinetic chain, and our running becomes less efficient.
Optimal stability of the foot includes our foot acting as a tripod. The 3 bases of the foot tripod include the head of the first metatarsal (big toe), the head of the 5th metatarsal (little toe) and the calcaneus (heel). Ground contact with all 3 of these points allow for optimal stability and controlled mobility.
To understand this concept, the use of a barefoot single leg balance self-assessment can be performed. The goal is to allow minimal to no wobbling of the foot and ankle by grounding yourself with the 3 points of contact previously discussed. You should be able to maintain an arch on the underside of your foot. Potential issues arise if any of the main 3 points of contact lift off the ground as this compromises your foot’s stability.
The next progression to further assess the stability and controlled mobility of our foot and ankle is controlled single leg rotation. If done correctly, we should be able to keep all points of contact via the foot tripod while our foot’s arch collapses into pronation and rises into supination. If we can move through these positions without difficulty or excessive compensation from the knee or hip, we can move forward.
Another piece to consider for foot health is toe dexterity, including toe splay and isolation control of our big toe. Our big toe is big for a reason, increased surface area results in enhanced stability when pressing into the ground. If our big toe can not maintain ground contact during the push off phase of gait (supination), then we compromise the stability of the foot. A simple, yet potentially difficult exercise to improve toe dexterity is Toe Yoga. The 3 movements to be able to master are as follows:
- Big toe pressing into the ground with lesser toes extending off the ground
- Lesser toes maintaining contact with the ground with big toe lifting off the ground
- Toe splay or spreading of the toes
Big Toe Flexion
Pulling Up the Big Toe as Big Toe Extension
Toe Splay
The ability to isolate and coordinate the toes allows for improved stability during the stance phase of running. If our foot is able to express its stability under the body’s load during running, then there’s less risk for compensation within the kinetic chain. A way to visualize the benefit of toe splay for stability, is if you were doing a hand-stand with varying hand-finger positions. If your fingers are clenched together, your hands have less stability to hold yourself upright, versus when your fingers are spread apart you have a much wider base of support for stability.
To further assess dynamic mobility and stability of the foot and ankle, a simple pogo hop drill can be performed. Pogo hops can be performed with both legs or single legged, and can be performed in place or in varying directions. The purpose of the pogo hop is to assess foot and lower limb energy storage and release as previously mentioned in this article. The shorter period of time our foot and ankle can go from pronation to supination on the ground, the more efficient our hop will be. This drill provides great insight into the efficiency of our foot hitting the ground while running, as most people I see within the clinical setting often have inefficiencies in the single legged pogo hop on the side they are having symptoms.
Energy Storage
Energy Release
When it comes down to it, our feet are the foundation to our running health. If we take care of our feet and ensure we have the adequate mobility, stability, and coordination we will have optimal use of our feet to progress our running for the future.
Editor’s Note: Check out even more articles by Sean Rimmer.
