Tell me about blood flow to the feet?
As with the rest of our body, ensuring that we get adequate blood flow to our feet is crucial to maintaining healthy, intact tissues and structures.
There are a number of blood vessels that travel between the very ends of our toes and the heart, for the purpose of this article, we will stick to the ones specific to the foot and ankle.
Blood supply to the top of our feet and front of our ankle comes from an artery called the Dorsalis Pedis artery (as pictured on the left, below). This artery bifurcates further down the foot becoming the dorsal metatarsal and digital arteries that supply the upper of our forefoot, toes and the skin surrounding.
The bottom of our feet get their blood supply from an artery we call the Posterior Tibial artery, which comes from the back of our lower leg, behind our ankle and down under the foot.
This artery also bifurcates to create the lateral and medial plantar arteries (as pictured on the right, above) that supply the left and right sides of the bottom of the foot, toes and skin surrounding.
The toes are the furthest body part from our hearts, this means that our blood flow has to be strong and efficient to ensure that even the very tips of our toes get the nutrient rich blood that they need to maintain healthy tissue, nails and hair (yes, it is normal to have hair on your toes!).
What changes do we physically see that are related to circulation as we get older?
Changes in micro-circulation (the very small blood vessels in our feet) can lead to problems such as:
- Delayed wound healing
- Decreased inflammatory response to trauma or infection
- Increased risk of infection
- Diminished ability to control temperature (changes in the appearance of the feet)
- Increased tendency to bruise as our capillaries (smallest blood vessels) are much more fragile and there is less protective padding around the foot due to changes in the amount of collagen produced by the body₂.
Sweating is also controlled by our micro-vasculature, so as changes occur we can have trouble regulating our core temperature which can sometimes lead to hypothermia or hyperthermia situations for the body₂.
What are the changes that we can’t see?
Our arteries are made up of three layers, and as we age the middle two layers become thicker due to changes in the structure of our collagen₂. The middle layer often loses some of its elasticity which means that when blood passes through, the vessel does not recoil and spring back to its original shape as it once did₂.
Stiff and thick walls in the artery can lead to a reduction in successful blood flow to the tissues further away from the heart (i.e. our feet and toes), an elevation in blood pressure as the vessels cannot expand as the heart is pumping to allow the blood to pass through smoothly, and an increased risk of atherosclerosis and blockages in our vessels.₂
Tell me about blood flow from the feet back to the heart?
How the blood gets from the feet back up to the heart is a bit of a different story.
As with arteries, we have vessels down to the tips of our toes that collect the deoxygenated blood and return it to the heart to be recycled.
The veins that operate around our toes are known as the plantar digital veins, these then empty into a number of smaller vessels before the blood makes it to the medial and lateral plantar veins.
There is a similar structure on the top of the foot. The blood then drains into the vessels of the leg known as the short saphenous, long saphenous, posterior tibial and anterior tibial veins. Behind our knee these vessels merge to form the femoral vein that takes the blood up into the torso.
As you can imagine, it’s not an easy task for the body to get blood back up the body as gravity is working against it. So how does the blood travel up?
Our veins move blood with the assistance of our blood pressure (how efficiently and with how much strength our heart is pumping the blood out), pressure coming from the muscles deep within our feet and legs, and little valves that are located along our veins that allow the blood through but then close up to stop a reverse flow of blood back down.
What happens to the veins as we get older?
The effects of ageing on veins is an area in which there is much to learn for researchers and specialists. This being said, we do know that the valves previously mentioned can often fail and this can lead to a reflux of blood down the vessel causing blood pooling and the expansion of veins₁.
The more superficial veins are called perforator or communicating veins and they can often become incompetent in pumping blood into the deeper veins of the leg₁.
Varicose & ‘spider’ veins: What are they?
Varicose veins are defined as dilated, tortuous, lengthened blood vessels that are the result of increased amounts of pressure within the walls of the vein₁. This can be a result of the above-mentioned valve failure, but can also be due to a number of other factors such as:
- Being female- our hormones, pregnancy and contraceptive use can all influence the likelihood of the appearance of varicose veins₁
- Genes- there is often a connection between our parents having varicose veins and us inheriting them, sometimes we just get lucky!
- Obesity- this makes it harder for our veins to return blood to the heart as there is extra pressure being placed on the vessels₁
- Standing up for long periods of time- that’s right, working on your feet all day and spending more time on your feet can lead to varicose veins! Gravity is working against us here as well as changes occurring in our muscles when we stand rather than sit and pop our feet up. ₁
“Spider” veins, or telangiectasias to get technical, are of a similar nature to varicose veins. The smaller blood vessels become dilated and the blood inside them becomes stagnant resulting in the blue/purple colour we can often see. A big contributing factor to developing these is pregnancy!
So what can I do to ensure my feet stay healthy in relation to blood flow?
- Regular exercise: this is a great way to keep your heart and vascular system healthy! Staying fit and healthy by doing regular exercise is not only great for avoiding problems with blood flow later down the track- but also for nearly every other system in your body as well!
- A healthy diet: high cholesterol or high sugar diets can cause something called atherosclerosis, as well as other changes to our blood vessels, so it’s a great idea to make sure we eat a healthy, well balanced diet and have regular checkups with our doctor!
- Come and see the podiatrist: Podiatrists have the skills and knowledge necessary to check on the vascular status of your feet. A regular check up to assess your vascular and neurological status is a great way to stay on top of the changes that can occur!
- Speak to your GP: Doctors can give you lots of information on how best to manage vascular changes in the body as we get older. They are here to help and there are no silly questions- make sure regular trips to the GP for a checkup are a priority!
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₁ Chuter, V. (2012) The Univeristy of Newcastle Vascular Manual
₂ Spink, M. (2016) Age Related Changes In Skin And Senses
Article by Jacqueline Horne
B Pod, MAPodA
Jacqueline Horne is a University of Newcastle Bachelor of Podiatry graduate.
Jacqui is particularly interested in diabetes and its effects on the lower limbs, sports related soft tissue injuries and orthoses manufacture for lower limb alignment.
"My aim is to make every patient feel comfortable whilst visiting us, and happy and pain free as they walk out the door!"