Let’s begin at the very bottom: your feet. When you go to a shoe shop, there are so many different options available to you, which is a good one? Most clinicians would say: it depends. Many people look at support, padding, high arch, low arch and often we forget about our little friends: the toes – in particular, the big toe.
Forming part of the bottom arch of our foot is the plantarfascia, a group of muscles and soft tissue that often gets sore or inflamed. Often, people would say they’re “flatfooted” or their “soles feel so tight”. As previously mentioned when we were talking about the SFMA and regional interdependence: everything in our body can affect everything else: this means poor hip movement can affect the foot and poor foot movement can affect the hip, knee and everything else higher.
The plantarfascia and foot works like a spring, often called a windlass mechanism; it absorbs the shock every time we plant our foot like a spring and redelivers that shock to propel us forward. One of the components that this spring needs is about 70 degrees of great toe extension which promotes a better foot arch and a better spring.
Have a look at an example of a client, with stiffness/restriction in his Right big toe, and adequate/desired range of motion in his Left big toe.
How does this work?
The plantarfascia covers the sole of the foot, when the great toe extends, it pulls on the plantarfascia and increases the arch like a bowstring being pulled and this contributes and assists in the propulsion of the foot, and by extension, locomotion i.e. walking and running. If the great toe can’t extend, the bowstring (plantarfascia) cannot be pulled and the bow (arch) cannot be as efficient. Thus, a good movement of the great toe is necessary to have good walking and running pattern.
What happens when it is less than 70 degrees? The body compensates, you still need to stand, walk and run.
Firstly, we cannot pull the bow, so the spring is less efficient. This would mean the plantarfascia at the bottom of the foot may need to work harder to deliver to force that propels us forward. Compensation may also come from the calves to give that power to propel us forward, causing increased loading through the calf, leading to calf strains.
When you are walking/running, the foot and the hip would then tend to rotate medially/inward as our picture depicts in the process of compensating for the lack of this great toe extension.
This would cause changes not only in the arch and windlass mechanism of the foot, but high up in the movement chain as well. This medial/internal rotation often comes from higher up such as the knee or hip which changes the way these joints work and cause pain. Symptoms may even appear in the back due to this change in hip and knee mechanics.
Closer to home, with people at the gym performing exercises such as lunges (forward and reverse), calf raises, or even more dynamic movements such as clean and jerks, or athletes who require big toe mobilty such as rugby props, you can see the (potential) compensations as depicted below.
Try out this test and see what your big toe is doing. Does it have the adequate range of motion? If not, you might want to get it checked out lest it might be contributing to issues elsewhere.
We hope this helps a little bit to explain the importance of the foot and especially the great toe! So even if you have other pains and issues, we may be checking from your toes as well!