Plantar fasciitis is a common issue for runners, with occurrence rates ranging from 4.5% to 10% annually; it accounts for around 8% of all running injuries.
It’s a disruptive injury that can derail training and routines, with the discomfort being persistent and easily aggravated. Although pain is usually felt at the calcaneal enthesis (bottom of the heel), some runners will also notice discomfort in the knee.
If you have been suffering from plantar fasciitis for a significant period of time, you may have adopted an abnormal gait pattern; it can put pressure on different parts of the body, including the knee.
This article aims to provide an analytical look at the relationship between plantar fasciitis and knee pain, common symptoms of plantar fasciitis, common causes of knee pain, and ultimately answer your question, can plantar fasciitis cause knee pain?
In this article, we will cover:
- What Is Plantar Fasciitis? Causes & Symptoms
- Can Plantar Fasciitis Cause Knee Pain?
- Common Causes Of Knee Pain
- Final Thoughts – Can Plantar Fasciitis Cause Knee Pain?
Ready? Let’s jump in!
What is Plantar Fasciitis? Causes and Symptoms
The plantar fascia consists of three bands of fibrous connective tissue that insert into the heel bone (calcaneus).
This structure extends towards the base of the toes, creating a robust mechanical connection between the heel and toes, with characteristics similar to both tendons and ligaments. This connection contributes to the foot’s spring-like movement.
A common musculoskeletal issue concerning the plantar fascia is plantar fasciitis. This condition mainly affects the point where the fascia attaches to the bone, known as the enthesis.
Contrary to the implication in its name, plantar fasciitis is primarily a fasciopathy rather than an inflammatory condition. To provide a more accurate description, it can be referred to as Chronic Plantar Heel Pain (CPHP).
Two of the most common causes of plantar fasciitis are overuse and poor foot biomechanics:
Studies have indicated that overuse of the plantar fascia is a significant factor leading to plantar fasciitis.
A study by Riddle et al. (2003) found that individuals who engaged in repetitive activities such as walking, running, or standing for prolonged periods can cause microtrauma to the plantar fascia and were more likely to develop plantar fasciitis.
If the plantar fascia is subject to relatively high levels of stress and force in a short time frame without adequate rest, this will lead to microdamage.
In particular, runners who increase their mileage too quickly or are just getting started are at risk of developing plantar fasciitis.
#2: Poor Foot Biomechanics
Issues like overpronation (where the foot rolls excessively inward), high arches, and flat feet have the potential to disrupt how forces are distributed across the plantar fascia.
This disruption can create an uneven distribution of stress and strain on the fascia, rendering it more susceptible to potential harm.
Inadequate biomechanics can prompt unusual movement patterns that exert additional pressure on the plantar fascia, adding to its wear and tear and eventual discomfort.
Next, we will look at the common symptoms that you can expect if you have plantar fasciitis:
- Heel Pain: You might notice this significant symptom – it often feels like a sharp or stabbing pain right at the bottom of your heel.
- Pain Upon Waking: The pain tends to be strongest when you take those first steps in the morning or after you’ve rested for a bit.
- Pain with Activity: Engaging in activities that involve standing, walking, or running can lead to increased pain.
- Stiffness: After you’ve been inactive for a while, you might experience some stiffness and discomfort in your heel and the arch of your foot.
- Pain Relief with Rest: The pain could ease up when you give your foot a break and take the weight off it.
- Pain Aggravation: If you spend a lot of time standing or walking, the pain might get worse as the day goes on.
- Radiating Pain: Sometimes, the pain might spread along the arch of your foot or even extend into your calf and/or knee.
- Tenderness: The area that’s affected could feel tender when you touch it, especially near your heel.
- Swelling: You might notice some slight swelling around the area.
- Reduced Range of Motion: You might find it a bit challenging to bend your foot upward due to the discomfort you’re experiencing.
Now that we know the common causes of plantar fasciitis and what symptoms we can usually expect, let’s get into “Can plantar fasciitis cause knee pain?”
Can Plantar Fasciitis Cause Knee Pain?
So can plantar fasciitis cause knee pain as well as foot pain? And what about the reverse, “Can knee pain cause plantar fasciitis?”
If you have been suffering from plantar fasciitis for a long period of time, you may have changed the way you walk, trying to avoid walking in ways that load the heel and cause pain.
Imagine it as a chain reaction: when the foot’s natural movement is compromised due to avoidance of plantar fasciitis pain, the knees may all of a sudden experience subtle shifts in their mechanics.
This altered movement pattern, although minor, can lead to additional stress on the knee joint. As this normally happens in a short space of time, the body will not be prepared for this new stress.
In my clinic in Brighton, it was common for clients to describe a new pain arising elsewhere whilst suffering from a musculoskeletal injury.
A recent study conducted by Saoussen Miladi et al. named “Is there an association between plantar fasciitis and knee osteoarthritis?” looked to explore the potential relationship between plantar fasciitis and knee osteoarthritis.
The researchers sought to determine whether there is a connection between these two conditions and to shed light on any possible associations.
Both these conditions have some shared risk factors like getting older, certain jobs, being overweight, and wearing inappropriate shoes. However, not much research has looked into whether the pain in the heels caused by plantar fasciitis is linked to knee osteoarthritis.
The study included 40 people with knee osteoarthritis, with an average age of around 60. They used different measures to assess the pain and function of the knees and feet. They looked at things like how far the ankles could bend and the arch shape of the feet.
By using ultrasound, they could determine if the plantar fascia (the tissue on the bottom of the foot) was thicker than normal.
They found that more than half of the people with knee osteoarthritis also had heel pain.
The plantar fascia was thicker than normal in many of these people. They also found that those with trouble moving their ankles, especially bending them upwards, were more likely to have plantar fasciitis.
In summary, the study showed that many people with knee osteoarthritis also had plantar fasciitis, and the main thing that seemed to increase the risk of plantar fasciitis was not being able to bend the ankles very well.
As we discussed earlier, if you have limited ankle mobility due to plantar fasciitis-related discomfort, it can affect how you walk, potentially leading to compensatory movements in the knee joint to maintain balance and stability.
There is no clear anatomical link between plantar fasciitis and knee pain. But it does appear that knee pain can develop in association with plantar fasciitis, although plantar fasciitis, in isolation, does not cause knee pain.
Common Causes of knee pain
If you are experiencing knee pain, here are some of the more common causes that may be worth investigating:
#1: Runner’s Knee (Patellofemoral Pain Syndrome – PFPS)
Let’s dive into a familiar foe of runners – the notorious Runner’s Knee, or scientifically, Patellofemoral Pain Syndrome (PFPS). This issue is no stranger to disrupting your running groove and temporarily benching your training.
This condition sets up camp around the patellar tendon. Runner’s knee likes to present with a gentle to moderate ache – think of it as the unwelcome guest at the front or back of your knee.
It makes its presence known when squatting and adds an extra dose of discomfort when you’re navigating stairs or running downhill stretches.
For a full look at this condition, check out:
Next up, we have a condition known as bursitis – a scenario where a tiny, fluid-filled pouch situated above and inside your knee or on your kneecap becomes inflamed.
The most common areas to experience bursitis are at the kneecap (prepatellar bursitis) or on the inner side of the knee just below the joint (Pes Anserine bursitis).
This situation can lead to a less-than-pleasant sensation at the front of your knee during bending or inner knee discomfort after your running escapades.
Why does it happen? Well, it’s like your body’s way of saying, “Hey, slow down a bit!” Often, it’s a reaction to pushing the mileage or intensity a tad too hard.
The treatment approach is all about easing the symptoms – we’re talking about rest, ice, heat, and perhaps some pain-relieving meds. And hey, reinforcing the strength of that knee is like adding extra security to prevent future aggravation.
#3: Meniscus Tear
Last but not least, we have the infamous meniscus tear. It’s the knee injury you might’ve heard about – when the cushioning cartilage between your shin and thigh bones decides to call it quits and tears.
How does this tear come about? Often, it’s a result of your knee getting a little more action than it bargained for – think sudden movements, abrupt twists, and overuse.
When dealing with a torn meniscus, the approach starts conservatively. Rest, ice, heat, and the trusty anti-inflammatory meds step in to calm things down.
Surgery isn’t always the star of the show – in many cases, once the pain and swelling take a hike, you’re back on track and ready to hit the running trail again.
Final Thoughts: Can Plantar Fasciitis Cause Knee Pain?
So can plantar fasciitis cause knee pain, and can knee pain cause plantar fasciitis?
Indirectly, yes, through the intricate interplay of our body’s mechanics. But both conditions are more commonly found to be mutually exclusive from each other.