Muscle
Sartorius
Long diagonal strap across the anterior thigh
High-yield
It forms the lateral edge of the femoral triangle and reaches the tibia with gracilis and semitendinosus at the pes anserinus. Its hip actions help position a bent leg across the opposite one.
Overview
Sartorius runs from the front of the pelvis toward the inner knee. Its oblique course crosses both joints, allowing it to assist hip and knee flexion while helping rotate the thigh outward.
Reference facts
- Origin
- Anterior superior iliac spine and adjacent notch
- Insertion
- Upper medial tibial shaft through the pes anserinus attachment
- Action
- Assists hip flexion, abduction and external rotation, plus knee flexion
- Innervation
- Anterior division of the femoral nerve, with L2-L3 commonly emphasized
- Blood supply
- Mainly muscular branches along the femoral artery, with additional regional collateral branches
Mnemonic
Trace a diagonal from the outer front of the pelvis to the inner upper tibia. At the tibia, add gracilis and semitendinosus to complete the three-tendon group.
Clinical correlation
The bursa beside the pes anserinus can become painful. Symptoms near the medial knee can resemble other problems, including a meniscal injury, so the site of pain alone does not identify the cause.
Frequently asked questions
What does the sartorius do?
The sartorius assists hip flexion, abduction and external rotation, plus knee flexion.
What nerve innervates the sartorius?
Anterior division of the femoral nerve, with L2-L3 commonly emphasized.
Where does the sartorius attach?
Origin: Anterior superior iliac spine and adjacent notch. Insertion: Upper medial tibial shaft through the pes anserinus attachment.
What is the blood supply of the sartorius?
Mainly muscular branches along the femoral artery, with additional regional collateral branches.