The biomechanical relationship between the tendoachilles, plantar fascia and metatarsophalangeal joint dorsiflexion angle

We carried out an experiment to measure the relationship between tensile fo rce in the tendoachilles and plantar fascia strain, and how this relationsh ip is affected by the metatarsophalangeal joint dorsiflexion angle. Eight c adaver lower extremity specimens underwent biomechanical testing. Using a s ervo-hydraulic testing machine, a tensile force up to 500 N was applied to the tendoachilles while the strain on the plantar fascia was measured using an extensometer. The experiment was repeated at four different metatarsoph alangeal joint dorsiflexion angles (0 degrees, 5 degrees, 30 degrees, and 4 5 degrees). Measurements and calculations showed that dorsiflexion of the t oes tightens the plantar fascia (the windlass effect) and increases the eff ect that a tensile force in the tendoachilles has on the tensile strain and tensile force in the plantar fascia.