- Plantar Fasciitis
- Windlass Mechanism
- 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.
Plantar fasciitis. The painful heel syndrome.
Dynamic Loading of the Plantar Aponeurosis in Walking.
Original Text by Clifford R. Wheeless, III, MD.
Last updated by Data Trace Staff on Wednesday, April 25, 2012 2:45 pm