Rectus Femoris
Thigh
The only quad that crosses both hip and knee — that's why it's vulnerable to 'rec fem' strains in soccer players.
Function
Extends knee, flexes hip
Origin
Anterior inferior iliac spine (AIIS) and superior acetabular rim
Insertion
Tibial tuberosity via patellar tendon
Innervation
Femoral nerve (L2-L4)