Plantar Fasciitis

See Also

Epidemiology

Most common cause of plantar Heel Pain
1. More than 1 Million patient visits per year in U.S.
Peak Incidence ages 40 to 60 years old
More common in women
Lifetime Prevalence in U.S.: 10%

Anatomy

Plantar fascia
1. Connective tissue band
2. Originates at medial tubercle of Calcaneus
3. Inserts at proximal phalanges at each Metatarsal head
Plantar fascia forms longitudinal foot arch stabilization
1. Important for normal gait
2. Plantar fascia cycles between stretch and contract while standing
3. More prone to overuse and injury in over-pronation (from limited ankle dorsiflexion)

Pathophysiology

Limited ankle dorsiflexion results in foot over-pronation, over-loading the plantar fascia
Repetitive micro-tears of the plantar fascia
Results in Collagen degeneration at medial calcaneal tubercle (plantar fascia origin)
Inflammation is not the primary process
1. Therefore, antiinflammatory approaches are less effective

Risk factors

Functional abnormalities
1. Athletes: Overuse Injury (especially runners)
  1. More time on feet increases risk of repetitive injury
2. Non-athletes
  1. Limited Ankle Dorsiflexion due to tight or weak Muscles or tendons (most common)
    1. Tight Achilles tendon or heel cord (limited ankle dorsiflexion)
    2. Tight or weak gastrocnemius or soleus Muscles
  2. Other risks
    1. Body Mass Index >27 kg/m2
    2. Standing or walking for most of workday
3. Older patients
  1. Mechanism
    1. Weak foot intrinsic Muscles
    2. Acquired flat foot
    3. Thinning of heel fat pad (exposes the plantar fascia insertion to compression)
  2. Characteristics of pain
    1. Localized pain in central heel
    2. First steps in morning not provocative
  3. Benefit from heel pads or heel cups
Anatomic abnormalities
1. Limited ankle dorsiflexion
2. Over-Pronated foot
3. Leg Length Discrepancy
4. Forefoot varus
5. Lateral tibial torsion
6. Femoral Anteversion
7. Abnormal longitudinal foot arch
  1. Low arch: Pes Planus (flat foot)
  2. High arch: pes cavus

Symptoms

Characteristic
1. Dull tooth-ache, throbbing, sharp or burning pain
2. Stiffness Sensation may also be present
Pain Location: Posterior and medial aspect of heel
1. Medial tubercle of Calcaneus
2. Medial longitudinal arch
Both heels often affected
Provocative
1. Pain worse with first few steps in morning
2. Pain may be worse at days end in severe cases
3. Worse after recent increase in weight bearing activity
4. Pain worse with first steps of run
  1. Pain worse during first 5-10 minutes of run
  2. Less pain during remainder of run
  3. Pain worsens after run completed
5. Pain worse with prolonged standing (weight bearing)
  1. Especially standing in hard shoes on hard floor
Palliative
1. Improves after first few minutes of activity

Signs

Focal point tenderness (and possible thickening, swelling or crepitus)
1. Calcaneus medial tubercle or tuberosity (anteromedial Calcaneus)
2. Beneath longitudinal arch at proximal plantar fascia
Provocative maneuvers to strain fascia and elicit pain
1. Stand on tips of toes
2. Passive dorsiflexion toes (Windlass Test)
  1. Examiner stabilizes ankle and dorsiflexes toes at MTP joints

Differential Diagnosis

See Heel Pain
Other causes of medial Heel Pain
1. Posterior tibial tendon dysfunction
2. Calcaneal Stress Fracture
3. Heel Fat Pad Syndrome
4. Sinus Tarsi Syndrome
5. Achilles Tendinopathy
6. Master knot of Henry Intersection Syndrome
  1. Friction between the flexor hallucis longus (FHL) and the flexor digitorum longus (FDL)
Paresthesias are typically absent in Plantar Fasciitis (consider Entrapment Neuropathy instead)
1. Baxter neuritis (Baxter Neuropathy)
2. Medial calcaneal nerve entrapment
3. Tarsal Tunnel Syndrome

Imaging
Foot Xray

General
1. Foot XRay is often normal
2. Indicated for refractory course >3 months
  1. Assess for tumor and other alternative diagnosis (see Heel Pain)
Traction spur or heel spur at Os Calcis (present in 50% of cases)
1. Spur directed distally
2. Spur is a response to Muscle tension
3. Seen in asymptomatic foot
4. No relationship between Heel Pain and spur formation (heel spur is not the cause of pain)
  1. Common in asymptomatic patients
  2. Persists after Plantar Fasciitis resolves
Calcaneus Stress Fracture (Calcaneus)
1. Assess for in chronic cases

Imaging
MRI

Indicated in severe refractory cases
Findings
1. Thickening of the proximal plantar fascia (to 7-8 mm)
2. Plantar aponeurosis inflammation
3. Reactive calcaneal marrow edema
4. Middle or proximal fascial rupture

Imaging
Ultrasound

Plantar fascia thickness >4 mm
Plantar Fasciitis has reduced echogenicity
Peritendinous edema
Intertendinous calcification

Management
Stage 1 Acute

Anticipatory guidance
1. Prolonged recovery expected: 6-18 months
NSAIDs (Analgesic effect)
1. Typically a suboptimal response as inflammation is not the primary process
Ice Therapy
1. See Local Cold Therapy
Relative rest with alternative activities
1. Consider switch to non-irritating activities
Avoid provocative activities
1. Avoid prolonged weight bearing
2. Avoid walking on hard surfaces
Pre-fabricated Orthotics (e.g. Superfeet Orthotics)
1. As effective as custom Orthotics in Plantar Fasciitis
2. Landorf (2006) Arch Intern Med 166(12): 1305-10 [PubMed]
3. Pfeffer (1999) Foot Ankle Int 20:214-21 [PubMed]
Properly fitting, newer Running Shoes
1. General
  1. Thicker, cushioned mid-sole
  2. Highly dense, vinyl acetate Running Shoe
2. Motion control shoe for Pes Planus
  1. Lasted construction
  2. External heel counter
  3. Wide flare
  4. Additional medial support
Other measures
1. Low-Dye Taping
  1. Reduces over-pronation by fixing the subtalar joint
  2. Reduces pain in the first week of application, but effectiveness wanes later
  3. https://www.youtube.com/watch?v=ZwMZ90BdYhw
  4. van de Water (2010) J Am Podiatr Med Assoc 100(1): 41-51 [PubMed]

Management
Stage 2 Stretching and Strengthening

General
1. Avoid Stretching the acutely painful foot
2. Consider early initiation of Posterior Night Splints for 3 weeks (see below)
Dynamic stretches and massage
1. Roll foot arch over Tennis Ball or 15-oz metal can
2. Cross friction massage over plantar fascia
Plantar fascia stretch
1. Sit with affected foot crossed over opposite thigh
2. Use one hand at base of toes on plantar surface
3. Pull toes toward shin (dorsiflex) until stretch felt
4. More effective than achilles tendon stretches
  1. DiGiovanni (2003) J Bone Joint Surg 85-A:1270-7 [PubMed]
Achilles Tendon stretches
1. Heel Stretching with towel
  1. Maximize passive dorsiflexion
  2. Pull with towel below foot (pull and release)
2. Calf stretches against wall
  1. Lean forward into wall onto outstretched hands
  2. Extend Stretching leg back behind you
  3. Move other leg forward in front
  4. Gastrocnemius stretch
    1. Legs slightly bent
  5. Soleus Muscle stretch
    1. Legs fully extended
3. Calf stretches using steps or boards
  1. Technique
    1. Toes on edge of step or board
    2. Heel drops down over edge of step
  2. Adjuncts
    1. Stair stretch
    2. Two-by-Four piece or wood
    3. Slant board
    4. Wobble board
  3. Pointers
    1. Consider using in places of prolonged standing
    2. Examples: By kitchen stove or sink
Strengthening of intrinsic foot Muscles
1. With heel on floor, pick up marbles with toes
2. Towel curls
  1. Sit in chair with a towel on the floor
  2. Place foot on towel, and keep heel firmly planted
  3. Use toes to pull towel toward body
3. Toe taps
  1. Keep heel on floor
  2. Raise all toes off floor
  3. Tap floor with great toe 10 to 50 times
  4. Tap floor with 4 lateral toes 10 to 50 times

Management
Stage 3 Refractory

Reconsider differential diagnosis of Heel Pain
Posterior Night Splints
1. Indicated if other measures not effective in 2 weeks
2. Most efficacious if symptoms >12 months
3. Mixed results for efficacy in studies
  1. Probe (1999) Clin Orthop Relat Res (368):190-5 [PubMed]
  2. Lee (2012) J Rehabil Res Dev 49(10): 1557-64 [PubMed]
Custom Orthotic: Semi-rigid, 3/4 to full length
1. Modestly effective for Pes Planus, but expensive
2. Provides longitudinal arch support
3. Controls over-pronation
4. Controls first Metatarsal head motion
5. Prefabricated Orthotics are as effective as custom Orthotics in Plantar Fasciitis
  1. Landorf (2006) Arch Intern Med 166(12): 1305-10 [PubMed]
Over-the-counter arch supports
1. Indicated for mild Pes Planus
Arch Taping or strapping
1. Transient support for under 30 minutes of activity
Heel Cup
1. Low efficacy in Plantar Fasciitis in general
2. Indications
  1. Short term use for acute injury
  2. Older adults with thinning fat pad
  3. Fat pad syndrome
  4. Heel Bruise
Local Corticosteroid Injection of Plantar Fascia
1. Effective in short-term, but less long-term benefits
2. As with NSAIDs, Corticosteroids are expected to be less effective for this non-inflammatory condition
3. Consider for 3-4 weeks of refractory symptoms
4. Risk of plantar fascia rupture (2.4% to 10% risk) or Heel Fat Pad Syndrome
  1. Acevedo (1998) Fook Ankle Int 19:91-7 [PubMed]
Short Leg Walking Cast for 6 weeks

Management
Stage 4 Referral

Podiatry or Orthopedic referral Indications
1. Failed conservative therapy as above for >6 weeks
Options
1. Platelet rich plasma injection
  1. Variable efficacy in studies
    1. Hsiao (2015) Rheumatology 54(9): 1735-43 [PubMed]
    2. Franchini 2018 Blood Transfus 16(6):502-13 [PubMed]
  2. Whole blood was as effective as Platelet rich plasma in some studies
    1. Vahdatpour (2016) Adv Biomed Res 5:84 [PubMed]
2. Botulinum Toxin Injection
  1. Improves pain and overall function in small 8 week studies
  2. Ahmad (2017) Foot Ankle Int 38(1): 1-7 [PubMed]
3. Extracorporeal Shock Wave Therapy
  1. Stimulates neovascularization, growth factors
  2. Reduces Substance P unmyelinated nerve fibers
  3. May be effective if 0.28 J/mm2 force is applied
  4. Lou (2017) Am J Phys Med Rehabil 96(8): 529-34 [PubMed]
  5. Rompe (2003) Am J Sports 31:268-75 [PubMed]
4. Plantar Fasciotomy (endoscopic without inferior calcaneal exostectomy)
  1. Reserved for refractory cases despite >12 months of conservative therapy
  2. Plantar fascia release at os calcis
  3. Risk of longitudinal arch flattening or collapse (Pes Planus)
  4. Incision scarring
  5. Cottom (2016) Clin Podiatr Med Surg 33(4): 545-51 [PubMed]

Prognosis

Slow resolution over 6 to 18 months
Good overall prognosis (esp. if treatment started within 12 months of onset)
1. Non-operative management resolves Plantar Fasciitis in 80-95% of patients
2. Davies (1999) Foot Ankle Int 20(12):803-7 +PMID: 10609710 [PubMed]

References