What's in a foot? Part 1

We're on them all the time and as dancers we ask quite a bit of them...especially if you are going en pointe. But how well do you know your feet? What magic lays beneath your skin working to get those toes pointed, that leg jumped? Well, over the next two blog posts I'm going to take you through the ins and outs of your feet, plus how you can strengthen them to both protect them and get the most out of them. In part one we look at the bones and intrinsic muscles......

Bones

There are 26 bones in the foot, making up 34 joints.

The rear foot contains 7 tarsals – the largest bones in the foot, irregular or cuboid in shape and bear the majority of your body weight when standing, mainly through the talus and the calcaneus.

The other bones are:

* Navicular

* Cuboid

* Medial (inside) cuneiform

* Intermediate (middle) cuneiform

* Lateral (outside) cuneiform

These bones can move in a few different directions (up / down, side to side) allowing movements such as pronation or inversion (rolling the foot) or eversion (sickling the foot) and assisting with balance and landing when working together with the bones of the midfoot.

The midfoot contains the 5 metatarsal bones. These are longer bones rather than cubed bones and provide articulation for movements such as walking between the rear foot and forefoot.

The forefoot contains 14 phalanges making up the toes. Each toe has three phalanges except for the big toe which only has 2.

These bones are so important to the foot and its function in dance.They:

*Provide a structure for the attachments of muscles, ligaments and tendons

* Provide leverage and articulate to create movement and propulsion

* Provide absorption and distribution of energy and force such as landing from a jump.

Intrinsic Muscles

In this section we will look at the intrinsic muscles on the underside of the foot. Many of these muscles are used in dancing for the finer articulations such as demi pointe work, expression and articulation when pointing the foot, pointework and landing from jumps. These intrinsic muscles work in conjunction with longer muscle complexes that originate from higher up the leg or knee. These will be looked at in part 2.

There are four layers of muscles in the underside of the foot. Yes! FOUR!

Starting from the fourth or deepest layer, there are four bipennate muscles (fibres fan out from a central tendon, similar to the calf muscles) between each of the tarsal bones called the dorsal interossei.

These serve to abduct (diverge) the tarsal bones and are on the dorsal (top) part of the foot.

Three muscles (plantar interossei) attached to the third, fourth and fifth toes join the tarsals and lower end of the metatarsals and work with the dorsal interossei to produce flexion (eg. Pointing your foot) and control the movement of the toes during movements like jumps.

The third layer has a number of longer muscles that run from the rear or midfoot to the base of the toe bones.

There is also a muscle running across the ball of the foot (adductor hallucis – transverse head) .

Combined, these muscles help to maintain the arch of the foot and flexes (points) the toes.

In the second layer, we have the lumbricals acting as a kind of accessory to the flexor digitorum longus, both pointing the toes and extending the toes (such as in demi pointe).

The outer most layer, the first layer, has three main muscles: The flexor digitorum brevis which points the toes, abductor hallucis which abducts the big toe (moves it outwards/ away) and the abductor digiti minimi which abducts the little toe.

Now that you know a little more about the intrinsic muscles and what they do, you can see why it would be important to ensure they are properly strengthened and flexible. The next section will go into a couple of exercises that can help strengthen these important muscles.

Strength and Flexibility

As with any strengthening exercise, the muscles need to be challenged in order to increase in strength

1. Ball plantarflexion

Previously, dancers have used TheraBand’s to help strengthen their feet, but new research shows that this needs to be done with care. The ballet blog has a great article on the how and why HERE. (You will need to sign up to the ballet blog for free to access the article “ Why we should avoid pointing into a TheraBand")

Instead, dancers can use a small Pilates ball instead slowly pointing the foot into the top of the ball and pressing down, articulating through the tarsal and metatarsal joints, then reversing into a flexed foot.

The key to this exercise and any other exercise pointing the foot is to keep the toes extended and long DO NOT crunch the toes! Repeat this exercise 10 – 15 times each foot.

2. Piano toes

Another exercise that works and challenges the intrinsic muscles, particularly those that work with abducting or adducting the toes is ‘piano toes’. This exercise starts off with the foot flat on the ground, with the toes flexed as if on demi-pointe. Then, one by one from the little toe, the toes are lowered to the ground. Repeat this exercise 3 – 5 times each foot, then repeat again, reversing the order! For a good demonstration of this exercise watch HERE.

3. Towel Scrunching

For this exercise you can use a thin towel or TheraBand laid flat underneath your foot (or both feet) with a large section extending out from the toes (this is the part you will scrunch) . Using the toes, you will gradually scrunch the towel by planting your toes down flat and drawing them towards your heel. Repeat up to 3 mins each foot, depending on your current strength. For a good demonstration of this exercise watch HERE.

Good luck! and stay tuned for part two which will go into more detail about the muscles in the foot, common injuries and more exercises!

*A reminder that this information is for educational purposes only and is not meant as a substitute for proper diagnosis or treatment by a medical professional.

Credits

Pictures:

Bones of the foot: http://heritance.me/bones-of-ankle-and-foot-labeled/bones-of-ankle-and-foot-labeled-human-anatomy-details-leg-bone-structure

Dorsal interossei: https://human-anatomycharts.com/v/dorsal-interossei-of-the-f.asp

Third layer of the foot: https://www.howtorelief.com/adductor-hallucis-origin-insertion-action-nerve-supply/

Second and First layer of the foot: https://www.orthobullets.com/foot-and-ankle/7003/layers-of-the-plantar-foot

Ball exercise: http://www.flx.life/foot-strengthening-release-1/2016/2/26/2-key-exercises-to-improve-your-arch

Bibliography:

de Mello Viero, C., et. al. (2017). Height of the Medial and Lognitudinal Arch During Classical Ballet Steps. JDMS, 21(3), 109 - 114. doi:10.12678/1089-313X.21.3.109

Haas, J. G. (2010). Dance anatomy. Champaign: Human Kinetics.

Hall, S. B. (2007). Basic biomechanics (5th ed.). New York: McGraw Hill.

Marieb, E. (1998). Human Anatomy & Physiology (4th ed.). Menlo Park: Benjamin /Cummings Science Publishing.