Exploring Plantar Fasciitis
We don’t often think about how important the bottom of our feet are. That is, we don’t think about it until we experience pain or dysfunction. Then we realize just how important healthy connective tissue is everywhere, including on the bottom of our feet. We need that tissue to be healthy and responsive in order to stand, walk, run, and do all kinds of daily tasks. When our feet aren’t able to support us, it can be very disruptive to all the things we need to do during the day. In this article, we’ll take a look at plantar fasciitis, one very common condition of the connective tissue on the bottom of our feet.
What is the plantar fascia?
Plantar fasciitis occurs in the plantar fascia, which is a sheet of connective tissue on the bottom of our foot. It attaches near the middle of the heel, then continues along the bottom of our foot to attach at the other end to the base of our toes. The tensile strength of the plantar fascia helps maintain the medial longitudinal arch in our foot, particularly when we take a step and put a lot of force down through the foot into the ground. The plantar fascia works as a cable to tighten and then release to help absorb shock as we step.
What is plantar fasciitis?
Plantar fasciitis occurs when the plantar fascia on the bottom of our feet is repetitively tugged away from its attachments on the bone. This can lead to irritation of the tissue and tearing (microtears). As a result, we can experience inflammation and eventually degeneration of the plantar fascia.
There may be inflammation associated with this condition. There is almost certainly pain. The typical pain pattern that most people feel is pain at the center of the heel and possibly along the rest of the sheet of plantar fascia. Most people report that the pain is the worst when they first get out of bed in the morning or when they stand up after a long period of sitting. This is common because your connective tissue cools and tightens overnight.
The plantar fascia becomes our Achilles tendon when we follow it up our leg. And of course, the Achilles tendon is the tendinous attachment of our gastrocnemius and soleus muscles. So, anytime we shorten the calf muscles, and therefore the Achilles tendon, it will also put tension on the plantar fascia. If we’re experiencing plantar fasciitis, then any action that changes the tension of the plantar fascia may also cause pain. Lifting the toes will change the tension on the plantar fascia from the other end, and can cause pain as well.
In some cases, plantar fasciitis can also be associated with bone spurs in the heel. The repetitive pulling of the plantar fascia away from its attachment on the heel bone can leave a space that our bone-building cells (osteoblasts) then fill in with more bone. Pain can come from just the pulling tension of the plantar fascia being tugged away from the attachment on the heel and/or the presence of a heel spur.
Of course, plantar fasciitis is not the only condition that causes heel pain or pain along the bottom of the foot. Conditions such as stress fractures, nerve impingements, aging-related atrophy, bursitis, and problems with the ankle or knee are among some of the other reasons for experiencing heel and foot pain. As with any symptom of pain or dysfunction in the body, it’s important to see an appropriate medical professional for a full assessment and diagnosis before seeking treatment.
What causes this condition?
The specific mechanisms that cause plantar fasciitis are unknown. Researchers have hypothesized several different types of biomechanical foot stresses that could lead to plantar fasciitis. For example, stresses on the plantar fascia can be exacerbated both by too much flexibility of the foot, especially excessive pronation. The plantar fascia can also be stressed by too much rigidity of the foot when it is not able to pronate enough to dissipate the forces going through the foot when we step onto it (Bolgla et al., 2004).
The causes of the pain symptoms characterized as plantar fasciitis are still being debated among researchers. Previously plantar fasciitis has been described as inflammation of the irritated plantar fascia. Some recent research suggests that what is actually happening is degeneration of the plantar fascia and therefore it should be called plantar fasciosis (Boakye et al, 2018). What seems likely based on research is that there is more than one condition or group of conditions that can lead to the experience of plantar fasciitis symptoms.
Factors that increase the likelihood of developing plantar fasciitis include:
- Biomechanical imbalances (too little arch, too much arch, too much flexibility, too much muscle tension, etc.)
- Long periods of standing or walking
- Sports or activities that include lots of running and/or jumping
- Issues with shoe-fit
Because there are different reasons that plantar fasciitis may occur, effective treatments vary depending on the situation causing the symptoms.
Least invasive treatments include:
- Reduce inflammation (anti-inflammatory meds: e.g. NSAIDS and/or ice)
- Discontinue activities that are causing the symptoms, rest, and let tissue heal
- Physical therapy to rebalance foot and leg muscle tension, address postural habits, and rehabilitate gait cycle if needed
- In some cases, researchers have found strengthening exercises for intrinsic foot muscles to be helpful, but research on strengthening as a treatment is currently inconclusive (Huffer et al., 2016).
More invasive treatments:
- Night splints
- Corticosteroid injections on the plantar fascia
- Extracorporeal shockwave therapy
Most invasive treatment:
While there are many reasons for heel and foot pain, one very common condition with those symptoms is plantar fasciitis. People who need to stand for long periods of time at their job and athletes who do a lot of running are particularly at risk. However, most people who experience this condition recover without needing surgery or invasive treatments.
Ribeiro, A.P., F. Trombini-Souza, V.D. Tessutti, F.R. Lima, S.M.A. Joao, and I.C.N. Sacco. 2010. The effects of plantar fasciitis and pain on plantar pressure distribution of recreational runners. Clinical Biomechanics. 26:194-199.