- See:
- Plantar Fasciitis
- Windlass Mechanism
- Anatomy:
- plantar fascia is a strong layer of white fibrous tissue whose thick central part is bounded by thinner lateral portions;
- central portion is attached to the medial calcaneal tubercle;
- as it progresses distally it divides into 5 sections, each extending into a toe and straddling the flexor tendons;
- superficial layer of each section attaches to deep skin fold between toes and the sole;
- deep layer blends with the fibrous flexor sheath on each proximal phalanx and sends speta to the deep transverse ligament of the sole;
- heel spurs: (see: heel pain)
- are not in the plantar fascia as is commonly thought but are found in the origin of the short flexors;
- they are present in 16% of normal population;
- Action and Function:
- stabilizes the arch;
- plantar aponeurosis provides stability of the 1st MP joint & medial arch thru its Windlass Mechanism;
- this plantarflexes the first metatarsal therby enabling the 1st metatarsal to carry the majority of body wt during last half of stance phase;
- if this mechanism is disrupted distally, plantar flexion does not occur and wt is transferred to the second metatarsal, often
resulting in a painful callus beneath 2nd metatarsal head;
- during normal walking, the plantar aponeurosis functions mainly during heel rise to toe off and prevents the calcaneous from everting;
- this mechanism brings about plantar flexion of metatarsals, which elevates and stabilizes the longitudinal arch, inverts the
calcaneus and externally rotates the tibia
Rupture of the plantar fascia in athletes.