Pathogenesis (development of disease)
The development of plantar fasciitis is considered multifactorial.
It is a mechanical overload reaction from that leads to repetitive microtrauma. As a result, bone material accumulates at the attachment of tendons, forming thorn-like bone outgrowths.
Depending on the location of the calcaneal spur, two forms can be distinguished:
- Lower calcaneal spur (= plantar calcaneal spur) – ossification in the attachment area of the small foot muscles on the underside of the calcaneus (plantar aponeurosis → plantar aponeuritis or plantar fasciitis: inflammation of the tendon plate of the sole of the foot) [most common form; plantar aponeuritis in flat feet; usually flattening of the longitudinal arch of the foot (eg. E.g., buckling flat foot); Cause: injury due to overloading with repetitive microtrauma of the plantar aponeurosis (coarse tendon plate (aponeurosis) on the planta pedis, which is stretched out between the foot muscles and the skin)]
- Upper or posterior heel spur (= Haglund heel or. Haglund exostosis) – ossification at the petrous attachment of the Achilles tendon, which is congenital or acquired [in athletes; shortened calf muscles (→ when rolling the foot does not stretch the muscle → extension in the upper ankle joint is blocked → increased forces at the attachments of the Achilles tendon and plantar fascia)Note: Haglund exostosis leads in the course to retrocalcaneal bursitis (bursitis). Affected are often women between 20 to 30 years; the finding is not uncommon bilateral (bilateral).
Etiology (causes)
Behavioral causes
- Misuse/overuse of the foot
- Predominant activities in standing and running activities.
- Change of footwear from padded shoes to thin soles
- Physical activity
- Athletes:
- Running (long distance runner)
- Sudden change of load (start of training after sports break).
- Athletes:
- Overweight (BMI ≥ 25; obesity).
Disease-related causes
Endocrine, nutritional, and metabolic diseases (E00-E90).
- Obesity (obesity)
Musculoskeletal system and connective tissue (M00-M99).
- Malalignments of the foot such as the bent-lowered foot and hollow foot (lat. Pes cavus or Pes excavatus)).
- Insertion tendopathy of the plantar fascia (soft tissue components of the connective tissue of the sole of the foot) at the calcaneus (heel bone) – irritation at the junction between tendons and bones (= insertion), which are usually caused by overloading.
- Shortening of the Achilles tendon
- Shortened calf muscles (83% of cases).
- Decreased mobility of the ankle joint