Introduction

Plantar fasciitis is a term used to described a clinical condition of heel and foot pain along the sole of the foot. It is the most common cause of foot and heel pain in adults. Despite the “-itis” implying inflammation, it is generally believed to be a degenerative condition, likely due to overuse.

The plantar fascia is a fibrous band of connective tissue that originates at the plantar tubercle of the calcaneum and runs along the sole of the foot, before dividing into 5 sections and connecting at the base of the toes. It’s fibres are also attached to the base layers of the skin of the sole of the foot.

It typically presents with heel pain, that is worse in the morning or after periods of activity, and settles during the day.

Epidemiology

  • Very common – about 0.8 – 1% of the population is affected at any given time.
  • Peak incidence – 40-60
  • More common in runners – and tends to occur at an earlier age
  • Bilateral in 1/3 of cases

Aetiology

The aetiology is multifactorial and not well understood. The only risk factor with a good evidence base is obesity, but other risk factors Are thought to include:

  • Obesity
  • Prolonged periods of standing
  • Jumping
  • Flat feet
  • Reduced ankle dorsiflexion
  • RIsk factors for runners
    • Sudden increase in training load- particularly distance (but also speed)
    • Poorly fitted running shoes
    • Running on hard surfaces
    • Flat or high arched foot

Heel spurs are often seen on x-ray in patients with plantar fasciitis but it is unclear if these are a cause or a result of plantar fasciitis. Heel spurs are associated with risk of foot pain.

Pathology

Pathological specimens of the plantar fascia from surgery typically show degenerative changes, without or without signs of chronic inflammation. There is often evidence of fibroblastic proliferation.

Plantar Fascia

Plantar Fascia

Presentation and diagnosis

Diagnosis is clinical, based on a history of pain around the heel, reproduced on palpation. Pain is typically worse when initiating walking and settles with longer periods of walking.

  • Pain worse in the morning or after period of inactivity
  • Pain typically eases with activity, but may worsen again later in the day after long periods of standing or activity

On examination

  • Dorsiflex the toes to stretch the plantar fascia
  • Palpate around the heel – tenderness typically in the anterior medio aspect of the heel, extending to the forefoot

Investigations

Blood tests

There are no laboratory tests that help with the diagnosis of plantar fasciitis, but they may help to rule out some of the differentials (see below). However, the diagnosis is usually straight forward and tests are not frequently required.

Imaging

Imaging is not routinely required.. X-rays may rule out a stress fracture.  The presence of heel spurs is not helpful in aiding the diagnosis.

  • Plantar fasciitis is more common in the presence of heel spurs, but as spurs exist in up to 30% of the population, they are not helpful in making the diagnosis.

USS and MRI can detect thickening of the plantar fascia but are not routinely performed.

Calcaneal bony spur

Calcaneal bony spur – nice to know what one looks like, but not useful for the diagnosis of plantar fasciitis

Differentials

 

Management

Most cases can be successfully managed with conservative therapy to, although it can take several months to resolve. Advise patients they may not notice a significant improvement for up to 6-8 weeks.

  • 80% of cases will resolve within 12 months

Be aware – there is not a lot of good evidence for any of the suggested treatments.

Conservative measures

  • Rest and avoid or modify aggravating activities
    • e.g. if runner – try running on soft surface, or a different training modality – i.e. cycling or swimming
  • Encourage weight loss if increased BMI
  • Stretching of the plantar fascia
    • This is the mainstay of treatment. Advise the patient to use a small hard ball (e.g. golf ball, cricket ball, hockey ball. Specific textured balls for this purpose are available from most pharmacies) and to roll the ball up and down the sole of the foot whilst applying pressure. Aim for 3×5 minutes per day (minimum)
    • Stretches – calf stretches, toe curls, foot-ankle circles
  • Avoid flat shoes and barefoot walking (e.g. slippers, flip-flops etc)
  • Try silicone shoe inserts (pre-made – no need for expensive orthotics initially)
  • Avoiding aggravating activities – e.g. running, dancing, long periods of standing, jumping)
  • Short course of NSAIDs – e.g. 2-3 weeks of ibuprofen 400mg TDS
  • Ice may be useful for analgesia – advise 10-12 minutes of ice (wrapped in something – e.g. t shirt or tea towel) with an hour off. Repeat x3.

Steroid injection

  • Should be considered if the above measures are not effective after 4-8 weeks
  • Injection(s) are usually given to the point(s) of most tenderness
  • Proven to provide good short term pain relief, but long term outcomes are mixed
  • Can cause heel pad atrophy and plantar fascia rupture – particularly if repeated injections are used – ensure to warn the patient about these potential complications before undertaking the procedure

Further Options

  • Orthotics – custom made shoe inserts – refer to podiatry for these
    • Good e die en to show that they can prevent injury – but not good evidence for treatment of injury
  • Night splint
  • Extracorporeal shock wave therapy (ESWT) – a type of sound wave therapy (traditionally used as a type of lithotripsy for renal stones, now also used often by a physiotherapist) which may have some modest clinical benefit – evidence is very limited
  • Immobilisation with cast
  • Surgery – may be considered in patients with a long history unresponsive to other treatments (12+ months)
    • A last resort
    • Complete or partial plantar fascia release is typically performed
    • No universally agreed upon technique

Prevention

  • Change running and walking shoes regularly
  • Choose shoes with good arch support and heel cushioning
    • Consider custom made orthotics
  • Aim for BMI in the healthy range
  • Regular stretching exercises for the plantar fascia

References