Which plantar muscle flexes the ankle

Strengthen small foot muscles

We runners have all heard of the importance of core stability and the importance of the muscles in the abdomen, lower back, and hips. An interesting article by a research group led by Irene Davis from Harvard Medical School, published in the British Journal of Sports Medicine, suggests that when it comes to stability, we should also think of the rather unknown small muscles in the foot that form the center of the foot or the center of the foot. form the "core of the foot".

When we talk about core muscles, there is an important distinction between "global drivers" (large, strong muscles that perform movements like sit-ups) and "local stabilizers". These are small muscles that sit mostly deep below the surface and move only a little, but are constantly activated to keep the body stable and balanced.

The same is true of the foot. There are large external muscles that run down the ankle into the foot and produce most of the movement of the foot; This is what we usually focus on during strength training. But there are also small muscles that lie entirely in the foot, some of which I have never heard of (e.g. abductor digiti minimi or quadratus plantae). They help us to keep the foot stable during touchdown and push-off - and deform to absorb the load and storage energy during the middle stance phase. It is crucial that these muscles support the arch of the foot.

How to train your foot muscles

What are the functions of the different foot muscles?

The human foot is made up of 26 bones and around 30 joints. There are also 60 muscles and more than 300 ligaments and tendons in the foot. The muscles are divided into the muscles of the dorsum of the foot and the muscles of the soles of the feet. The latter is divided into three further areas:

Big toe muscles

The muscles of the big toe include the spreader, the puller and the long and short flexor muscles. The spreader allows the first toe to be splayed outwards. It can also produce a slight diffraction. This muscle begins at the bottom of the heel and extends to the metatarsophalangeal joint of the big toe. The long flexor muscle serves primarily to support the arch of the foot, which can prevent malpositions of the feet.

Little toe muscles

As the name suggests, the muscles in this muscle group are responsible for moving the little toe. The opposing little toe, for example, performs a coherent movement of flexing and pulling the little toe after being excited by the associated nerve. It can also happen that this muscle is absent. Next to it is the flexor muscle of the little toe, which flexes in the direction of the sole of the foot. The spreader forms the side edge of the foot. Contrary to what the name implies, this muscle has very little splaying function.

Muscles in the middle / between the toes

All muscles that fall into this category support the other muscles and perform important tasks in stabilizing the foot. For example, the lumbicral muscles that support the flexing movement of the toes and pull the toes towards each other. They also increase the stability of the entire foot. Another muscle is the quadrilateral muscle, which strengthens the arch of the foot and helps the long toe flexor. The muscles that lie between the toes are grouped together as the interbone muscles. They lie on the sole of the foot as well as on the back of the foot and have a toe-attracting or splaying effect.

In addition, the muscles are divided into their different lengths. The short foot muscles of the back of the foot, also called intrinsic foot muscles, lie on top of the bone and perform dorsiflexion. This means that they are responsible for stretching and pulling the toes. The toe extensor (extensor hallucis brevis muscle) is solely responsible for moving the big toe. Toes two to four are moved by the short toe extensor (extensor digitorum brevis muscle). However, only indirectly, as this muscle is divided into three muscle bellies and one tendon extends from each to the toe. The fifth and smallest toe often does not have a tendon that attaches to a short muscle.

The long muscles of the back of the foot, also called extrinsic muscles, has, as the name suggests, a very long course that begins at the knee joint, has the muscle belly on the lower leg and only runs in the form of tendons over the back of the foot to the toes. Similar to the short muscles of the foot, they are involved in flexing and stretching the toes. In addition, they trigger movement in the ankle. The long toe extensor starts at the bone of the knee joint, runs diagonally towards the ankle and divides there into four tendons that go to toes two to five. The long big toe extensor (extensor hallucis longus muscle) is involved in the movement of the big toe.

Strengthen foot muscles, prevent plantar fasciitis

So what happens when you have a weak "foot core"? There are four different muscle layers along the bottom of the foot that support the arch of the foot. When these muscles are too weak, the stress is transferred to the plantar fascia (fibrous ligamentous tissue on the underside of the foot). So if you want to get rid of an inflammation in this area called plantar fasciitis, the key is to strengthen the inner muscles of the foot - but this is often neglected. And of course everything in our body is related: An unstable core of the foot can also lead to abnormal movement in the knee, which ultimately results in knee pain.

What runners should know about plantar fasciitis

So now it would be important to find out how to strengthen the core of the foot. There are a few Standard exercises that activate the inner muscles of the foot:

The toe eater

Try pulling a towel across the floor under your foot with your toes.

The toe gripper

Pick up marbles with your toes.

However, these exercises often also involve the larger external foot muscles. So the scientists at Harvard Medical School suggest another exercise:

The arch of the foot

Sit in a chair and place your foot flat on the floor in a neutral position. Now try to arch the soles of your feet by contracting the inner, small muscles while keeping your toes flat on the floor. You can increase the level of difficulty later by doing the exercise standing rather than sitting, then walking on one leg and even hopping.

Foot muscles are often neglected

But is there really any evidence that this helps? It will certainly make a small improvement in the dynamic balance and stability of the ankle, but overall much more research is needed in this area. At the moment, it is a reminder that this area in the foot is often neglected. Study leader Irene Davis therefore says: “I hope that the athletes take away that they should pay more attention to their feet. Because so far we haven't seen anyone in the gym who strengthens their feet. "


The foot is made up of around 26 bones, 30 joints, 60 muscles, and more than 300 ligaments and tendons. When it comes to muscles, a distinction is made between the back of the foot and the sole of the foot. The muscles of the sole of the foot are again divided into the muscles of the big toe and the small toe as well as the muscles in the middle and between the toes. You can also categorize the muscles based on their length.

With plantar fasciitis, the muscles in the soles of the feet are too weak, which is why inflammation develops. To get rid of them, you should do strengthening exercises. The exercises toe eater, toe gripper and arch of the foot are suitable for this.

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