Vastus Medialis
Thigh
The 'teardrop' muscle above the knee — VMO weakness is linked to kneecap tracking problems.
Function
Extends knee, stabilizes patella
Origin
Intertrochanteric line, linea aspera (medial lip)
Insertion
Tibial tuberosity via patellar tendon
Innervation
Femoral nerve (L2-L4)