BI2333 – Practical Anatomy
Lateral leg and sole of foot
Dr Helen McCarthy, Dr Kirsty Richards
Lateral leg – Fibularis group
Involved in eversion (pronation) in the lower ankle joint, plantar flexion in the
upper ankle joint and the tendon of the fibularis longus muscle gives lateral
arch support. Both muscles lie within the peroneal compartment located at the
lateral fibular region.
Innervated by the superficial fibular nerve, a branch of the common fibular
nerve.
The tendons of both fibularis muscles run caudally towards the foot, behind the
lateral malleolus and then ventrally along the lateral foot edge. They are lead
by 2 canal-like peroneal retinacula and the inferior fibular retinaculum
stretches between the inferior extensor retinaculum and the anterior muscles
of the lower leg and calcaneus.
Fibularis longus
Fibularis brevis
i. Fibularis longus
Origin: Lateral aspect of the fibula, head of the fibula and
the intermuscular septum
Insertion: Medial cuneiform bone and the first metatarsal
bone
ii. Fibularis brevis
Covered by the fibularis longus muscle
Origin: fibula
Insertion: Tuberosity of the 5th metatarsal bone
Nerves
The nerve begins at the apex of the popliteal fossa, where the sciatic
nerve bifurcates into the tibial and common fibular nerves.
The common fibular nerve follows the medial border of the biceps
femoris gives rise to two cutaneous branches at the lateral head of
the gastrocnemius.
To enter the lateral compartment of the leg, the nerve wraps
around the neck of the fibula, passing between the attachments of
the fibularis longus muscle. Here, the common fibular nerve
terminates by dividing into the superficial fibular and deep fibular
nerves.
Lateral leg and sole of foot
Dr Helen McCarthy, Dr Kirsty Richards
Lateral leg – Fibularis group
Involved in eversion (pronation) in the lower ankle joint, plantar flexion in the
upper ankle joint and the tendon of the fibularis longus muscle gives lateral
arch support. Both muscles lie within the peroneal compartment located at the
lateral fibular region.
Innervated by the superficial fibular nerve, a branch of the common fibular
nerve.
The tendons of both fibularis muscles run caudally towards the foot, behind the
lateral malleolus and then ventrally along the lateral foot edge. They are lead
by 2 canal-like peroneal retinacula and the inferior fibular retinaculum
stretches between the inferior extensor retinaculum and the anterior muscles
of the lower leg and calcaneus.
Fibularis longus
Fibularis brevis
i. Fibularis longus
Origin: Lateral aspect of the fibula, head of the fibula and
the intermuscular septum
Insertion: Medial cuneiform bone and the first metatarsal
bone
ii. Fibularis brevis
Covered by the fibularis longus muscle
Origin: fibula
Insertion: Tuberosity of the 5th metatarsal bone
Nerves
The nerve begins at the apex of the popliteal fossa, where the sciatic
nerve bifurcates into the tibial and common fibular nerves.
The common fibular nerve follows the medial border of the biceps
femoris gives rise to two cutaneous branches at the lateral head of
the gastrocnemius.
To enter the lateral compartment of the leg, the nerve wraps
around the neck of the fibula, passing between the attachments of
the fibularis longus muscle. Here, the common fibular nerve
terminates by dividing into the superficial fibular and deep fibular
nerves.
