What are the possible causes of plantar foot pain that occurs both while walking and while sitting in a woman?

Plantar Foot Pain: Causes and Diagnostic Approach

The most common cause of plantar foot pain occurring both while walking and sitting is plantar fasciitis, which affects over 1 million persons per year and presents with characteristic heel pain during first steps in the morning or after prolonged sitting. 1

Primary Differential Diagnoses

Most Common Causes

Plantar fasciitis is the leading diagnosis when pain localizes to the plantar heel region, particularly with:

• Sharp pain with palpation of the medial plantar calcaneal region 1
• Discomfort elicited by passive ankle/first toe dorsiflexion 1
• Pain present both with weight-bearing and at rest after prolonged sitting 1

Metatarsalgia should be considered when pain affects the forefoot (ball of the foot):

• Results from functional disorder or anatomic derangement of forefoot architecture 2
• Represents the most frequent reason for consultation in foot pathology 2
• Pain typically worsens with walking and standing 3

Risk Factors to Assess

Key risk factors that increase likelihood of plantar fasciitis include:

• Obesity 1
• Excessive foot pronation 1
• Excessive running or prolonged standing 1
• Sedentary lifestyle transitioning to increased activity 1

Critical Diagnostic Features

Location-Based Diagnosis

Heel pain suggests:

• Plantar fasciitis (medial plantar calcaneal region) 1
• Calcaneal stress fracture (lateral calcaneal wall, slightly posterior to subtalar joint) 4
• Insertional Achilles tendonitis (tendon insertion site) 4

Forefoot pain indicates:

• Metatarsalgia affecting metatarsal heads 3, 2
• Morton's neuroma (intermetatarsal plantar nerve) 3
• Stress fractures of metatarsal bones 2

Physical Examination Findings

For plantar fasciitis:

• Point tenderness at medial plantar heel 1
• Pain with passive dorsiflexion of ankle and first toe 1
• Worst pain with first steps after rest 1

For stress fracture:

• Pain on compression of calcaneus from medial to lateral (calcaneal squeeze test) 4
• Tenderness at lateral calcaneal wall 4
• History of increased walking activity before symptom onset 5

For metatarsalgia:

• Point tenderness at base of metatarsal bones 6
• Pain at metatarsophalangeal joints 6
• Presence of calluses or deformities 5

When Imaging Is Needed

Initial imaging is NOT routinely required for plantar fasciitis diagnosis, which is primarily clinical 1. However, consider imaging when:

• Symptoms persist despite 6-8 weeks of conservative treatment 4
• Stress fracture suspected (technetium bone scan if radiographs negative) 5, 4
• Need to rule out other pathology (MRI or ultrasound shows increased plantar fascia thickness >4mm) 1

Red Flags Requiring Immediate Evaluation

Neurologic symptoms warrant subspecialist referral for:

• Burning or tingling sensations 4
• Electromyography and nerve conduction studies 5
• Possible nerve entrapment or impingement 5

Diabetic patients require urgent assessment for:

• Pre-ulcerative signs (blisters, calluses, hemorrhage) 5
• Loss of protective sensation 5
• Signs of infection 5

Common Pitfalls to Avoid

Do not assume a single diagnosis - pain present both while walking AND sitting suggests:

• Plantar fasciitis (pain after rest is characteristic) 1
• But also consider inflammatory conditions if bilateral 4
• Stress fractures cause progressive worsening, not intermittent pain 4

Do not delay reexamination - if initial assessment is limited by swelling within 48 hours, reexamine at 3-5 days when findings become more reliable 4, 6

Do not overlook footwear - ill-fitting shoes are the most frequent cause of foot ulceration and pain, even in non-diabetic patients 5

Initial Management Algorithm

For suspected plantar fasciitis (most likely diagnosis):

1. Rest and activity modification 1
2. Ice massage to affected area 1
3. NSAIDs for pain and inflammation 1
4. Stretching exercises for plantar fascia and Achilles tendon 1
5. Heel cushions or arch supports 1
6. Weight loss if obesity present 1

If no improvement after 6-8 weeks, escalate to:

• Physical therapy modalities 1
• Custom foot orthotics 1
• Night splinting 1
• Consider corticosteroid injections (but avoid near Achilles tendon) 4

Ninety percent of patients improve with conservative treatment within this timeframe 1.