Mechanisms underlying the development of Plantar Fasciitis
Date of this Version
Traditionally, plantar fasciitis has been viewed as a mechanical ‘overuse’ injury, in which lower limb biomechanics resulting in elongation of the medical longitudinal arch of the foot were thought to create excessive tensile strain within the plantar fascia, microscopic tears and chronic inflammation. The fact that inflammatory cell infiltrate is rarely observed in chronic cases of plantar fasciitis has reduced support for this thinking and the role of abnormal arch mechanics in the development of plantar fasciitis is currently equivocal. Factors previously considered to predispose to the condition, such as the structure of the medical longitudinal arch, midfoot loading and the energy dissipating properties of the heel pad, are likely to act as aggravating factors influencing levels of pain rather than initiators of the condition. Although the mechanisms underlying the development of pain in plantar fasciitis are unknown, and research to contribute to its understanding is underway, the roles of bending, shear and compression force, as well as neuromuscular and genetic components, are important considerations.