Ankle Joint Complex and Motion

Ankle Joint Complex

• Distal Tibio-fibular Joint: Fibrous joint (syndesmosis), triangular zone formed by the inferior part of the fibula and inferior external facet of the tibia.
• Tibio-fibular-talar Joint: Trochlear joint with a single degree of freedom. This joint involves the tibiofibular mortise (concave) and the talar pulley (convex).
• Subtalar Joint: Trochlear joint with a single degree of freedom. The upper surface of the talus (concave) articulates with the upper surface of the calcaneus (convex).

Range of Motion

• Dorsiflexion: 20° to 30°
• Plantarflexion: 30° to 50°
• Inversion: Includes plantarflexion, approximation, and supination
• Eversion: Includes dorsiflexion, separation, and pronation

Main Ankle Muscles

• Anterior Tibial: Dorsiflexion and inversion
• Large Extensor of the Thumb: Dorsiflexion
• Common Extensor: Dorsiflexion and eversion
• Short Lateral Peroneus: Plantarflexion and eversion
• Long Lateral Peroneus: Plantarflexion and eversion

Tests

Soleus Length Test

• Procedure: Patient stands with heel supported and foot separated from a wall. Patient tries to touch the knee with the wall.
• Outcome: Distance from the first finger to the wall is measured. Less than 11 cm indicates possible soleus shortness.
• Significance: Decreased ankle mobility linked to soleus shortness.

Heel Rise Test

• Procedure: Patient stands and raises up onto their tiptoes.
• Outcome: Positive if the calcaneus does not change from valgus to varus during the test.
• Significance: Weakness of the posterior tibial muscle if calcaneus doesn't change position during the test.

Landing Test

• Procedure: Patient stands on a step and performs a one-legged landing.
• Outcome: Instability is observed if instability during the landing occurs.
• Significance: Weakness of the peroneal muscles.

Star Excursion Balance Test

• Procedure: Patient stands on one leg and touches the eight tips of a star. This test examines balance and proprioception.
• Outcome: Distance reached and stability are important factors. Instability is noted if there are issues with reaching the targets.
• Significance: Muscle imbalances, lack of flexibility, and proprioception issues are revealed if the patient demonstrates difficulty reaching the targets or if they lose balance.

Explore the intricacies of the ankle joint complex, including the distal tibio-fibular joint, tibio-fibular-talar joint, and subtalar joint. Learn about the range of motion in dorsiflexion, plantarflexion, inversion, and eversion, as well as the main muscles involved in these movements. This quiz is perfect for students studying human anatomy and physiology.