The Knee Complex - Nerves

4. Nerves (6-minutes): Identification and demonstration of the relevant nerve pathways and their relationship to key muscular structures. Follow-up questions may explore structure, function and motor/sensory roles. "Tell me about the nerves relevant to the knee complex."

What are the two main nerves of the lower limb?

The Femoral nerve and the Sciatic nerve

Where does the Femoral nerve exit the spine?

The Femoral nerve exits the spine at L2-L4

Where does the Femoral nerve go after exiting the spine?

Travels anteriorly to the Lumbar Plexus (Anterior Iliac Fossa)

Where does the Femoral nerve go after travelling to the Lumbar Plexus?

Passes between Iliopsoas (Iliacus + Psoas Major)

Where does the Femoral nerve go after passing between Iliopsoas?

Splits into two divisions ≈2cm distal to the Anterior Superior Iliac Spine

Where does the Femoral nerve division go after splitting at the Anterior Superior Iliac Spine?

Travels distally along the anterior Femur to the halfway point between the Anterior Superior Iliac Spine and Pes Anserine as the Femoral nerve

Where does the Saphenous nerve division go after splitting at the Anterior Superior Iliac Spine?

Travels distally along the anteromedial Femur to the knee and continues as the Saphenous nerve down the anteromedial Tibia

What muscles are innervated by the Femoral nerve?

Vastus Lateralis, Vastus Intermedialis, Vastus Medialis, Rectus Femoris, Sartorius, Iliacus,

Where does the Sciatic nerve exit the spine?

The Sciatic nerve exits the spine at L4-S3

Where does the Sciatic nerve go after exiting the spine?

Travels to the Sacral Plexus (Anterior to the Sacrum)

Where does the Sciatic nerve go after travelling to the Sacral Plexus?

Passes through the Sciatic Notch

Where does the Sciatic nerve go after passing through the Sciatic Notch?

Travels halfway between the Greater Trochanter and Ischial Tuberosity

Where does the Sciatic nerve go after passing between the Greater Trochanter and Ischial Tuberosity?

Travels distally along Biceps Femoris

Where does the Sciatic nerve go after travelling along Biceps Femoris?

Splits into two at the Popliteal Fossa

Where does the Common Peroneal nerve go after splitting at the Popliteal Fossa?

Continues to the Neck of Fibula as the Common Peroneal nerve

Where does the Deep Peroneal nerve go after splitting at the Neck of Fibula?

Travels down the anterior Tibia to the big toe as the Deep Peroneal nerve

Where does the Superficial Peroneal nerve go after splitting at the Neck of Fibula?

Travels down the Fibula to the Lateral Malleolus as the Superficial Peroneal nerve

Where does the Tibial nerve go after splitting at the Popliteal Fossa?

Travels along the Gastrocnemius to the posterior aspect of the Medial Malleolus as the Tibial nerve

What muscles at the knee complex are innervated by the Sciatic nerve?

Semitendinosus, Semimembranosus, Biceps Femoris Long Head, Biceps Femoris Short Head

What muscles at the knee complex are innervated by the Tibial nerve?

Popliteus, Gastrocnemius (Medial and Lateral Belly)