What is the root value of the sciatic nerve?
Ventral rami of L4, L5, S1, S2, and S3.
The sciatic nerve is a combination of which two nerves?
The tibial nerve and the common peroneal (fibular) nerve.
How does the sciatic nerve leave the pelvis?
Through the greater sciatic foramen, inferior to the piriformis muscle.
Does the sciatic nerve give off any branches in the gluteal region?
No
Where does the sciatic nerve usually divide into its two terminal branches?
Halfway or more down the thigh (at the apex of the popliteal fossa).
Which side of the sciatic nerve is the “danger side” for injections?
The medial side (because branches arise from this side).
Which muscles are supplied by the tibial part of the sciatic nerve?
Semitendinosus, semimembranosus, long head of biceps femoris, and the hamstring part of adductor magnus.
Which muscle is supplied by the common fibular (peroneal) part?
The short head of biceps femoris.
What is the sensory distribution of the sciatic nerve?
Skin below the knee, except for the areas supplied by the saphenous and obturator nerves.
Where is the “safe area” for gluteal injections to avoid the sciatic nerve?
The upper outer quadrant of the buttock.
What is “Sciatica”?
Pain along the distribution of the sciatic nerve, often caused by a herniated disc (L4/L5) compressing spinal nerves.
What gait is associated with a lesion of the tibial portion of the sciatic nerve?
Shuffling gait (due to loss of plantarflexion).
What are the two main motor losses in a common fibular (peroneal) nerve lesion?
Loss of dorsiflexion and eversion.
What clinical condition and gait result from a common fibular nerve lesion?
“Foot drop” and High stepping gait.
What is the result of a complete sciatic nerve lesion?
The leg becomes useless (exte
