The fibular head is an anatomical landmark at the upper end of the fibula, the smaller lower leg bone. Situated near the knee joint, it articulates with the lateral condyle of the tibia, contributing to the superior tibiofibular joint. Despite the fibula itself not being a primary weight-bearing bone, its head serves as an attachment point for several muscles and ligaments, playing a role in leg movement and stability. Understanding the muscles that connect to this area is key to lower limb mechanics.
Muscles Attaching to the Fibular Head
Muscles attach to the fibular head, contributing to leg and foot movements. These include the Biceps Femoris, Fibularis Longus (Peroneus Longus), and Soleus. Their attachments allow for force transmission and coordinated actions across the knee and ankle joints.
The Biceps Femoris, a muscle of the posterior thigh, has two heads with a common insertion. Its short head originates from the femur, while both heads’ common tendon inserts onto the lateral aspect of the fibular head. This muscle is the most posterior structure inserting into the fibular head.
The Fibularis Longus is located in the lateral compartment of the lower leg. It originates from the head and the upper two-thirds of the lateral surface of the fibula. Its fibers converge into a tendon that descends along the leg.
The Soleus muscle, a broad, flat muscle forming part of the calf, also originates at the fibular head. Specifically, it originates from the posterior surface of the fibular head and the upper third of the fibula’s shaft. It lies deep to the gastrocnemius muscle.
How These Muscles Move the Leg
The muscles attaching to the fibular head facilitate diverse movements, particularly at the knee and ankle joints. They enable actions such as bending the knee, rotating the lower leg, and moving the foot.
The Biceps Femoris acts at the knee. It flexes, or bends, the knee. When the knee is slightly bent, it contributes to external, or outward, rotation of the lower leg. The long head of the Biceps Femoris also extends the hip.
The Fibularis Longus plays a role in ankle and foot mechanics. Its actions include eversion of the foot (tilting the sole away from the midline) and assisting in plantarflexion of the foot (pointing the toes downward). This muscle helps maintain the arches of the foot.
The Soleus muscle contributes to ankle movement. Its main function is plantarflexion of the foot, working with the gastrocnemius to extend the foot downward. This action is important for activities such as walking, running, and maintaining upright posture by resisting forward sway.