The Peroneus Brevis, also known as the Fibularis Brevis, is a significant short muscle situated in the lower leg, playing a key role in ankle movement. It is located in the lateral compartment of the lower leg, positioned deep to the Fibularis Longus muscle.
Muscle Overview
The Peroneus Brevis is one of the three muscles collectively known as the fibularis muscles (or peroneal muscles), all of which are primary ankle everters.
- Name: Peroneus Brevis (Fibularis Brevis)
- Location: Lateral lower leg
- Position: Deep to Fibularis Longus
- Type: Short muscle
- Primary Action: Ankle Eversion
Location and Anatomy
The Peroneus Brevis originates from the lateral surface of the fibula bone in the lower leg. Its tendon runs downwards behind the lateral malleolus (the bony prominence on the outside of the ankle) and typically inserts onto the tuberosity of the fifth metatarsal bone in the foot.
Key Anatomical Details:
- Origin: Lateral surface of the fibula
- Insertion: Tuberosity of the fifth metatarsal
- Path: Runs deep to Fibularis Longus tendon behind the lateral malleolus
Function: Ankle Eversion
Along with the Fibularis Longus and Fibularis Tertius, the Peroneus Brevis is classified as an ankle everter. Eversion is the movement that turns the sole of the foot outwards. This action is crucial for stability when walking or running on uneven surfaces.
Fibularis Muscles (Ankle Everters):
- Fibularis Longus
- Fibularis Brevis
- Fibularis Tertius
These muscles work together to stabilize the ankle and foot, preventing excessive inward rolling (inversion), which can lead to ankle sprains.
Clinical Significance
The Peroneus Brevis tendon is susceptible to injury, particularly sprains or tears, often associated with ankle instability or overuse. Issues with this muscle or its tendon can cause pain and difficulty with ankle movement, especially eversion. Proper strength and flexibility of the fibularis muscles are important for preventing such injuries.
