How to Perform a Detailed Ankle and Foot Examination: A Complete Guide for Medical Students

Introduction

Ankle and foot examinations are crucial components of a thorough musculoskeletal evaluation. These examinations are often required to diagnose various conditions ranging from traumatic injuries to chronic diseases such as arthritis. For medical students and healthcare professionals, mastering this examination is essential not only for accurate diagnosis but also for patient management and treatment planning.

This guide will provide a detailed, step-by-step approach to performing a comprehensive ankle and foot examination, with an emphasis on clinical techniques, interpretation of findings, and common pathologies.

Anatomical Overview

Before diving into the examination, it is important to have a strong understanding of the anatomy of the ankle and foot. The ankle joint, or talocrural joint, is a hinge joint formed by the distal tibia, fibula, and the talus. The foot consists of 26 bones, divided into the hindfoot (calcaneus and talus), midfoot (navicular, cuboid, and three cuneiforms), and forefoot (metatarsals and phalanges). Ligaments, tendons, and muscles play vital roles in stabilizing the ankle and foot while allowing for a wide range of movements.

Patient History

Before beginning the physical examination, obtaining a detailed patient history is crucial. Key aspects to inquire about include:

• Mechanism of Injury: If the patient presents with an acute injury, ask about the specific circumstances. Was it a twist, direct impact, or fall? Understanding the mechanism can provide clues about potential injuries.
• Pain Characteristics: Ask about the location, onset, duration, and intensity of the pain. Is it sharp, dull, constant, or intermittent?
• Previous Injuries or Surgeries: A history of previous injuries or surgeries can affect the current presentation and may indicate a recurrent or chronic condition.
• Associated Symptoms: Inquire about swelling, bruising, numbness, tingling, or weakness in the foot or ankle.

Inspection

Begin the physical examination by visually inspecting both the ankle and foot. This step should be done with the patient both standing and sitting.

1. Standing Inspection:
   • Observe the patient’s gait. Look for any abnormalities, such as limping or altered foot positioning.
   • Examine the alignment of the foot and ankle. Pay attention to any signs of pes planus (flatfoot) or pes cavus (high arch).
   • Check for swelling, which can indicate acute injury or chronic conditions like edema.
2. Sitting Inspection:
   • Look for any deformities, such as bunions, hammertoes, or claw toes.
   • Assess for skin changes, including redness, bruising, or discoloration.
   • Check the toenails for fungal infections, ingrown nails, or other abnormalities.

Palpation

Palpation is a critical step in identifying areas of tenderness, swelling, or deformity. It should be systematic and cover all relevant structures.

1. Ankle Palpation:
   • Medial Malleolus: Palpate along the medial aspect of the ankle, checking for tenderness or swelling, which may indicate a medial ligament injury or fracture.
   • Lateral Malleolus: Similarly, palpate the lateral malleolus. Tenderness here may suggest a lateral ligament injury or fracture.
   • Achilles Tendon: Palpate the Achilles tendon for tenderness, thickening, or nodules, which could indicate tendinopathy or rupture.
2. Foot Palpation:
   • Midfoot: Palpate the navicular and cuboid bones for tenderness. Pain in these areas can suggest midfoot fractures or arthritis.
   • Forefoot: Palpate each metatarsal, particularly at the heads and bases. Tenderness here can be a sign of metatarsal fractures or Morton’s neuroma.
   • Plantar Fascia: Palpate along the plantar fascia, especially at the heel. Tenderness here is characteristic of plantar fasciitis.

Range of Motion (ROM) Assessment

Assessing the range of motion is essential to evaluate the functional status of the ankle and foot. The ROM assessment includes both active (performed by the patient) and passive (performed by the examiner) movements.

1. Ankle Joint:
   • Dorsiflexion: Ask the patient to point their toes upward. Normal dorsiflexion ranges from 0 to 20 degrees.
   • Plantarflexion: Ask the patient to point their toes downward. Normal plantarflexion ranges from 0 to 50 degrees.
2. Subtalar Joint:
   • Inversion: Ask the patient to turn the sole of the foot inward. Normal inversion ranges from 0 to 30 degrees.
   • Eversion: Ask the patient to turn the sole of the foot outward. Normal eversion ranges from 0 to 15 degrees.
3. Forefoot:
   • Toe Flexion and Extension: Ask the patient to curl and then straighten their toes. This helps assess the flexibility and strength of the forefoot.

Special Tests

Special tests are designed to diagnose specific conditions. Here are some of the most commonly used tests in ankle and foot examinations:

1. Anterior Drawer Test:
   • This test assesses the integrity of the anterior talofibular ligament (ATFL). With the patient sitting and the ankle in a neutral position, grasp the heel with one hand and stabilize the tibia with the other. Gently pull the heel forward. Excessive forward movement or a "clunk" indicates a positive test, suggesting ATFL injury.
2. Talar Tilt Test:
   • This test evaluates the integrity of the lateral ligaments. With the patient sitting, stabilize the tibia and invert the foot. Increased laxity compared to the other foot indicates a possible ligament injury.
3. Thompson Test:
   • The Thompson test assesses for Achilles tendon rupture. With the patient lying prone and their feet hanging off the edge of the table, squeeze the calf muscle. A positive test occurs if the foot does not plantarflex, indicating a ruptured Achilles tendon.
4. Squeeze Test:
   • This test is used to assess for syndesmotic (high ankle) sprains. Squeeze the tibia and fibula together at the mid-calf level. Pain in the lower leg or ankle suggests a positive test, indicating a syndesmotic injury.
5. Morton’s Neuroma Test:
   • To test for Morton’s neuroma, compress the metatarsal heads together and ask the patient if they feel pain or a clicking sensation between the third and fourth toes. A positive test indicates Morton’s neuroma.

Neurological Examination

A comprehensive ankle and foot examination should also include a neurological assessment. This involves testing the sensory and motor function of the nerves that supply the ankle and foot.

1. Sensory Testing:
   • Superficial Peroneal Nerve: Test sensation over the dorsum of the foot.
   • Deep Peroneal Nerve: Test sensation between the first and second toes.
   • Tibial Nerve: Test sensation on the plantar surface of the foot.
2. Motor Testing:
   • Tibialis Anterior: Ask the patient to dorsiflex the ankle and invert the foot (tests the deep peroneal nerve).
   • Peroneus Longus and Brevis: Ask the patient to plantarflex and evert the foot (tests the superficial peroneal nerve).
   • Gastrocnemius and Soleus: Ask the patient to stand on tiptoes (tests the tibial nerve).
3. Reflex Testing:
   • Achilles Reflex: The Achilles reflex tests the S1 nerve root. Tap the Achilles tendon with a reflex hammer and observe for plantarflexion of the foot. Diminished or absent reflexes may indicate nerve root pathology.

Vascular Examination

Assessing the vascular status of the ankle and foot is crucial, especially in patients with diabetes or peripheral vascular disease.

1. Palpation of Pulses:
   • Dorsalis Pedis Pulse: Palpate the dorsalis pedis artery on the dorsum of the foot. Absence or diminution of this pulse may suggest vascular insufficiency.
   • Posterior Tibial Pulse: Palpate the posterior tibial artery behind the medial malleolus. Like the dorsalis pedis pulse, an absent or weak pulse may indicate peripheral vascular disease.
2. Capillary Refill:
   • Assess capillary refill by pressing down on the patient’s toenail until it blanches and then releasing. The color should return within 2 seconds, indicating adequate blood flow.

Common Pathologies and Their Examination Findings

Understanding the typical examination findings associated with common ankle and foot pathologies is essential for accurate diagnosis and treatment. Here are some examples:

1. Ankle Sprain:
   • Inspection: Swelling and bruising over the lateral ankle.
   • Palpation: Tenderness over the anterior talofibular ligament.
   • ROM: Painful and limited inversion.
   • Special Tests: Positive anterior drawer and talar tilt tests.
2. Plantar Fasciitis:
   • Inspection: Often normal.
   • Palpation: Tenderness over the medial calcaneal tuberosity and along the plantar fascia.
   • ROM: Pain with dorsiflexion of the toes.
   • Special Tests: None specific, but pain is often elicited with palpation.
3. Achilles Tendon Rupture:
   • Inspection: Visible gap in the Achilles tendon.
   • Palpation: Tenderness and palpable gap in the tendon.
   • ROM: Weakness in plantarflexion.
   • Special Tests: Positive Thompson test.
4. Morton’s Neuroma:
   • Inspection: Often normal.
   • Palpation: Tenderness between the third and fourth metatarsals.
   • ROM: Normal.
   • Special Tests: Positive Morton’s neuroma test.
5. Tarsal Tunnel Syndrome:
   • Inspection: Often normal.
   • Palpation: Tenderness over the tarsal tunnel, posterior to the medial malleolus.
   • ROM: Normal.
   • Special Tests: Positive Tinel’s sign when tapping over the tarsal tunnel.

Documentation

Proper documentation of your findings is essential. Include details about the patient’s history, the steps of the examination, and the results of each test. This documentation will be critical for formulating a treatment plan and for future reference.

Conclusion

Performing a thorough ankle and foot examination requires a systematic approach, detailed knowledge of anatomy, and an understanding of common pathologies. By following this guide, medical students and healthcare professionals can improve their diagnostic skills and provide better patient care.