The plantar fascia originates from the a region on your foot called the medial calcaneal tuberosity.  It is found on the under surface of the foot and is the most common site where patients complain of pain due to plantar fasciitis.  The plantarfascia  fans out from this area to be inserted into the toes(metatarsophalangeal joints). It plays a vital role in maintaining the arch of the foot (See Figure 1).

Figure1: The Plantarfascia

What is Plantar fasciitis?
Plantar fasciitis is an extremely common foot complaint in both the sporting and non-athletic population. Inflammation of the plantar fascia and the intrinsic muscular attachments of the hindfoot often present itself as localized pain, often exquisite in intensity, at their attachments into the heel bone.   Pain is often gradual and insidious in onset, worse in the early morning on rising, or after a period of non-weightbearing time during the day. Pain can increase until, in the worst cases, weight-bearing becomes difficult without a walking stick or crutches. Risk factors for injury include the following:

1. A sudden increase in sporting activity.
2. A change of running surface.
3. Inadequate arch support and/or inadequate cushioning in footwear.
4. Tightness of the Achilles tendon.

There can also be a history of a change in footwear habits, either a period of walking without shoes, or using footwear with very low heels, especially in the summer months. The main biomechanical cause is that of foot overpronation (See Figure 2), which increases the stress on the plantar fascia  The condition usually resoves itself over 18 to 36 months, for as the heel spur forms, the distance between its points of attachments reduces, and so does the tensile stress.

With activities such as walking and running repetitive traction is placed on the plantar fascia. This may cause microtears with an associated reparative inflammatory response. During sleep the foot tends drop down and turn in with associated shortening of the plantar fascia. If the fascia is inflamed it will tend to stiffen in this shortened position. On rising in the morning the sudden stretching of the fascia (that occurs on weightbearing) may cause further damage and perpetuation of the injury.

Figure 2: Back view of a severely

over-pronated right foot

Diagnosis
Early morning pain of an insidious onset reducing as the morning progresses, with tenderness at the attachment of the plantar fascia into the heel bone, should alert the therapist to the possibility of a diagnosis of plantar fasciitis. Other diagnoses that my present like plantar fascitiis include:

1. Sub-calcaneal bursitis.
2. Stress fracture of the calcaneus.
3. Medial calcaneal nerve entrapment.
4. Partial tear of the plantar fascia.
5. Severs disease in children 8 to 12 years old.
6. Inflammation of the plantar fascial structures distal to the plantar enthesis.

(Note: Your therapist will be able to differentiate between these other forms of heel pain)

Examination confirms localized tenderness on the medial (inner) aspect of the heel around the origin of the fascia. The combination of the tender site and early morning stiffness distinguishes plantar fasciitis from other causes of inferior heel pain. Occasionally, plantar fasciitis is due to an underlying sero-negative arthropathy. The athlete should be assessed for other features of these conditions. A plain lateral x-ray may be helpful to exclude other causes of heel pain and may also show erosion at the enthesial site suggesting a sero-negative arthropathy. Occasionally heel spurs are seen. Ultrasound and MRI may show thickening, inflammatory change or degenerative change of the fascia. The normal plantar fascia is usually no more than 3 mm in thickness but may increase to 6 to 10mm in severe cases. MRI may also be helpful in excluding other diagnoses such as a calcaneal stress fracture. Ultrasound has been used to guide local injection into the fascia. Blood tests will help to exclude inflammatory causes of fasciitis while nerve conduction studies will help to exclude nerve entrapment.

Treatment
This consists of the following:

1. Relative rest from weightbearing activity.
2. NSAIDs: these are often helpful in the early stages of the injury.
3. Corticosteroid injection: this may help to reduce the pain. However there are significant risks associated with this, which include fat pad atrophy (causing loss of cushioning on the under surface of the foot) and plantar fascia rupture (causing loss of the medial longitudinal arch).
4. Night splints. These are moulded ankle-foot orthoses which should fix the ankle in about 5 degrees of dorsiflexion. They should be worn throughout the night to maintain a constant stretch on the fascia. By doing this, there is usually a considerable reduction in early morning symptoms.

Since the etiology of damage to the plantar fascial tissues (including the plantar intrinsic musculature) has a large mechanical component, it follows that mechanical treatment should be most effective. The following may be helpful:

1. Padding and taping (valgus pad with low dye taping) is often immediately effective even in acute cases.
2. Gait evaluation
3. Functional orthoses (See Figure 3): a medial arch support to reduce the stretch on the fascia on walking, a cushioned heel pad and supportive footwear (rather than open sandals).
4. Footwear advice: flat shoes or barefoot walking/sport should be avoided. Minimal heel height should be no less than 1.5 cm.

Figure3: Correction of foot posture

with an orthotic.

Physiotherapy Can Help!:

Physiotherapy input involves manual massage techniques to promote circulation for healing. Stretches to the plantar fascia and the Achilles tendon help to improve posterior heel soft tissue flexibility. It is important to prevent excessive eversion/pronation movement faults during the stretching of the Achilles tendon. Supports can be prescribed and taping can be used to off-load the plantar fasciitis.  Strengthening exercises should be given to the medial arch support muscles and should include flexor hallucis longus, abductor hallucis, tibialis posterior, and lumbricals. Gait re-training exercises should be given to alter any excessive pronation during stance phase walking/running (general weightbearing activities).

Surgical treatment: Surgery is usually not considered until symptoms have been present for about 12 to 18 months. Many techniques have been described: medial incisions, transverse incisions, arthroscopic etc. The proponents of each technique usually describe good results but many others have described poor results with surgery. Most surgeons perform a medial approach and divide only up to two thirds of the fascia and excise any spur if present. Complete division of the plantar fascia can lead to a painful flat foot. The patient is allowed to weightbear as tolerated with crutches.