- Plantar fasciitis refers to pain in the connective tissue membrane of the sole of the foot.
- It usually increases during or after exercise or exertion.
- Symptoms may also occur the first thing in the morning.
- Persisten symptoms are usually associated with other functional disorders in the pelvic and lower limb areas and other factors that predispose the pain to become chronic.
Functional anatomy of the sole of the foot
The plantar fascia is a connective tissue membrane in the sole of the foot that attaches to the heel bone and the base of the toes. Functionally, it is a very important part of the overall function of the foot and ankle, providing support.
In practice, whenever the foot touches the ground, it is mainly the plantar fascia, in cooperation with the arches and muscles of the foot that absorbs the impact. Due to the supportive and shock-absorbing properties of the plantar fascia, in sports such as running, the plantar fascia is typically loaded with every step. The amount of load depends on several factors, such as hereditary structure, the functioning of the musculoskeletal system, the intensity and amount of load, walking and running technique, control of the body’s center of gravity, body weight, general fitness, and accident and medical history.
Pain in the sole of the foot (plantar fasciitis)
Plantar fasciitis is a Latin term that refers to inflammation of the sole of the foot. A typical symptom is sharp, localized pain in the sole of the foot near the heel bone. The pain is usually felt more on the inside of the foot, along the midline. Typically, the pain is most severe when starting to exercise and in the mornings. This makes it difficult and painful to start moving. The pain may also worsen after prolonged sitting or standing. The pain usually subsides after the first few minutes of exercise, but worsens again if the exercise continues.
Recent scientific articles recommend changing the name of plantar fasciitis, as cellular studies have not found inflammatory cells, which are always present in inflammatory conditions. As a result, despite its name, this condition is now classified as a degenerative disorder caused by overuse. Previously, in connection with the inflammation theory, imaging findings of thickening at the attachment point of the plantar fascia were interpreted as a so-called heel spur, which causes pain in the sole of the foot. Based on current knowledge, this normal finding has been found to occur in both symptomatic and asymptomatic individuals. These findings have led to the current conclusion about the functional cause of plantar fasciitis.
How does the plantar fascia function as part of the body?
There is no structure in the human body that does not function more or less in cooperation with all other structures of the body. The normal function of plantar fascia as connective tissue is mainly related to supporting the arch of the foot, absorbing shock, and functioning as part of the kinetic chain of the lower extremities. As a supportive and guiding connective tissue, it does not create movement itself, but enables the movement and function created by the nervous system and muscles by supporting the arches of the foot with a so-called winch mechanism. In the windlass mechanism, vertical load on the foot is transferred through the arches to the plantar fascia, causing the arches to become more pronounced and stable.
Our muscles form kinetic chains through connective tissue, in which, for example, when running, the muscles of the foot are activated in cooperation with the hip when the foot hits the ground. There are several kinetic chains in the foot, because the hip, as a ball-and-socket joint, allows movement in all directions. As a result, some of the kinetic chains in the foot function vertically, while others also rotate structures. The plantar fascia mainly functions as part of the chain running along the back of the foot, which consists of the gluteal, hamstring, and calf muscles, the Achilles tendon, and the plantar fascia. Due to their direct connection, functional disorders (most commonly stiffness and weakness) in these structures have the greatest impact on the load placed on the plantar fascia at the muscle and connective tissue level.
Causes of persistent foot symptoms
Prolonged symptoms are usually caused by a combination of several factors rather than just one of the factors listed below.
- Physiological load due to previous overweight, injuries, congenital premature wear, or functional disorders, especially in the lower back, pelvis, knee, ankle, and foot areas on the same side.
- Insufficient or excessive physical load.
- Impaired balance and coordination.
- Psychological factors, such as anxiety, depression, and/or excessive mental strain.
- Lifestyle factors, such as too little or too repetitive exercise, insufficient or poor-quality sleep, and/or obesity.
- Central nervous system sensitization of the pain system.
You can easily test the stiffness of the sole of your foot and its effect on the kinetic chain with a forward bend test:
- Try bending forward and see how far down you can bring your fingers.
- Find a hard, round object, such as a ball (a hockey puck is recommended!), a full bottle, a rolling pin, etc., with which you can roll the plantar fascia lengthwise for about 20 seconds, within the limits of comfort.
- Try the forward bend again and note any difference. If the plantar fascia is stiff and tense, the difference will be significant.
Foot sole treatment and rehabilitation
Treatment usually includes:
- Manual therapy to treat joint, muscle, and fascia dysfunctions.
- Individual strenghtening, coordination, and balance exercises to improve posture and movement.
- Acupuncture to treat pain and pain sensitization.
- Lifestyle guidance to improve exercise, sleep, rest, and eating habits.
Read more about other pain syndromes
Hip flexor pain (Psoas syndrome)
Viimeksi päivitetty 13.10.2025
