Before I start talking about the causes themselves, I am going to give you a general view and I will talk in more depth later on.
Plantar fasciitis is common in people between 40 and 60 years of age, being more common in women. This condition is presented in sports and occupations that require people to stand, walk or run on hard surfaces for long periods of time. For example, runners, postmen, nurses and dancers. It is fairly common in overweight people.
And here are the causes in more detail:
Training errors and faulty equipment
- Sudden increases in mileage (“too much, too soon, too fast”). Don’t start training like crazy or running as much as you used to do before getting injured. Your body has to get used to the new situation, it needs to adapt.
- Too much hill and speed work. Same as before, take it easy.
- Not stretching your calf muscles properly and, therefore, you get very tight calf muscles which leads to prolonged and / or high velocity pronation of the foot. This produces repetitive overstretching of the plantar fascia leading to injury.
- Running on hard surfaces which increases impact.
- Inappropriate footwear. High heels which will shorten your Achilles tendon and, therefore, will put more stress on your plantar fascia (remember that your plantar fascia is attached to your Achilles tendon); flip-flops, because, unless you have really strong foot and ankle muscles, your feet won’t have enough support, your feet might overpronate and your plantar fascia will be overstretched all the time; and worn shoes, for the same reason as flip-flops. Your shoes should be flat, lace-up and with good arch support and cushioning. The reality, although many people are against this, is that changing your shoes or putting insoles or orthotics in them usually helps to reduce symptoms. But, the ideal way to act would be to have strong muscles to support your arch.
- Poor flexibility and strength of the plantar flexor muscles ( muscles of your sole). Have a look at the study Functional biomechanical deficits in running athletes with plantar fasciitis by Kibler WB et al..
- Overstretching of the Achilles tendon resulting from intense muscle contraction and passive stretching of tight Achilles tendon. See research Effect of Achilles tendon loading on plantar fascia tension in the standing foot by Cheung J.T. et al.
Anatomical and biomechanical factors
- Excessive pronation (feet rolling in), as it causes continuous strain of the fascia and, therefore, pain. Apparently 81-86% of people with plantar fasciitis have excessive pronation. If you ask many physios, they will agree with this, although, you can also find research which says the opposite Risk factors associated with the development of plantar heel pain in athletes by Keith Rome et al.
- Overweight. It is due to the excess weight impacting on the foot which will cause increased strain on the fascia, leading to degeneration, and thus pain. Obesity is present in up to 70% of patients with plantar fasciitis.
- Pregnancy (particularly during late pregnancy). Weight gain over a short period of time causing increased stress on the fascia. Hormonal changes play an important role, as they will increase the flexibility of the fascia beyond normal.
- Decrease in ankle dorsiflexion. Normal gait requires a minimum of 10° of dorsiflexion at the ankle joint. If the patient has less than 10° of dorsiflexion, the foot will compensate by pronating and increasing the stress on the plantar fascia.
- Flat feet, high arches or an abnormal pattern of walking. They affect the way your feet support your weight, putting added stress on the plantar fascia and making it overwork.
- Heel or calcaneal spurs and decreased first metatarsophalangeal joint extension (movement of your big toe upwards) are also risk factors, as you can see in this study Factors associated with chronic plantar heel pain by Irving D.B. et al. Notice that this doesn’t mean that if you have heel spurs, you will get plantar fasciitis.
- Continuous shortened position of the sole muscles. For example, driving for long periods can cause this injury in the foot controlling the accelerator.
This injury is sometimes related to underlying diseases associated with arthritis (joint inflammation) such as rheumatoid arthritis, Reiter’s disease or ankylosing spondylitis.
Help us to improve this blog by leaving a comment.
If you have any questions, do not hesitate to contact me on The Physical Therapy, Physiotherapy Clinic in Southampton, and I will be happy to help you.
If you are a health professional and would like to read more in scientific terms, follow this link Plantar fasciitis : a concise review by Emily N Schwartz et al.