Imagine you have a pain under the inside of your heel and every morning when you get up it causes more pain for the first few steps. It’s painful when you run or after your run, and it’s probably been around for a few months.
Most likely this is plantar fasciitis. In runners, about 8-10% of all of the running problems we see in our clinics, are plantar fasciitis.
It’s a funny name, but to understand it, first you need to know what the plantar fascia is.
It’s really quite a complex structure, a lot more complex than many people think. It’s like a really thick rubber band that spreads out, joining the underside of your heel to the underside of the bones in your toes, goes around the muscles, joins to the skin under your foot, at the heel and then joins onto your Achilles and calf muscle.
So that’s in simple terms what your plantar fascia is, and you probably now want to know what a plantar fascia does!
Well to answer that, let’s start with the foot. In your foot, you have 26 bones. You have so many bones (plus 2 more under your big toe when you’re older), because the foot is a really complex structure that lets you do some many things:
- It makes sure you can walk across uneven ground and climb trees
- It helps you to create force when running or jumping
- and helps your foot to absorb shock when running or landing from a jump – actually in every single step you take it’s helping you absorb shock
The plantar fascia is really important in helping out all of those things.
Like I said the plantar fascia joins from your heel to the underside of your toes. The bones in your feet form together to make arches like 3 bridges, and the really cool thing about the 3 bridges is that they all join and work together, but they need other things to help support them.
So, at the bottom of these 3 bridges you have this wonderfully strong fascia (rubber band) underneath the foot which holds them together. Because this strong band is also connected to muscles under the foot, it helps you to control the bridges and to do this, the band can get tighter if needed – making it stronger when you go up onto your toes or start walking/running. Getting stronger means you can create more power or absorb more shock.
Kapandji – the plantar vault
But imagine if instead of having the pressure mostly coming straight through the middle of your foot (where the arrow is), it was more on the inside edge of the foot and at the same time, to compensate, the big toe has move outwards – the result would be that the bridge on the inside of the foot would be tacking a lot more pressure than it should.
Because it’s clever, it could cope with the pressure for a short while, but after time the part of the band on that side of the foot would not be able to hold, and it would start to tear. This is how plantar fasciitis begins.
Can you also imagine another thing that might happen? If all of the bridges are super strong but locked (that means no movement), they would have no give in them, meaning that if you jumped or ran there would be a ‘jarring’ force going through the foot. This ‘jarring force’ would hurt the softer areas of the foot and could even lead to breaks or stress fractures in your bones over time!
The extra shock through the band will start to cause breaks and small painful tears will likely start to occur. If you are at all over weight, this will be increased even further because of the extra load going through that area.
So that’s basically what the plantar fascia does and a common example of how it can become damaged. Most commonly it’s the breaking down of the band near where it joins onto your heel bone, where the problem usually occurs.
If you can relate to the pain explained above and would like to understand if your symptoms could be caused in this way, please contact our team on: 02 8607 4000 or request a call: https://www.precisionphysio.com.au/request-a-call/
Kapandji (1987). The Physiology of Joints, Vol the lower limb. Edinburgh. Churchill Livingston. pg219
J Anat. 2013 Dec;223(6):665-76. doi: 10.1111/joa.12111. Epub 2013 Sep 12.
Plantar fascia anatomy and its relationship with Achilles tendon and paratenon.
Taunton JE, Ryan MB, Clement DB, et al.(2002). A retrospective case-control analysis of 2002 running injuries. Br J Sports Med. 2002;36(2):95–101.