MUSCLES-QUADRICEPS FEMORIS

SUMMARY

1. RECTUS FEMORIS - spindle-shaped muscle (bipenniform) that arises from the ileum by 2 heads. Reflected head - from above the acetabulum. Straight head - from the AIIS. Above the patella it flattens to form the anterior lamina of the quadriceps tendon. 

2. VASTUS LATERALIS - arises from the upper 1/2 of the intertrochanteric line + lateral lip of the linea aspera + upper 2/3 of the lateral supracondylar line + lateral intermuscular spetum. It spirals down to be inserted into the quadriceps tendon. 

3. VASTUS INTERMEDIUS - arises from the anterolateral surface of the upper 2/3 of the femur. It continues into the quadriceps tendon. 

4. VASTUS MEDIALIS - arises from the spiral line + medial lip of the linea aspera + tendon of the ADDUCTOR MAGNUS. Its lowest fibers are inserted into the medial border of the patella, important for patellar stability (VM obliquus mechanism). The rest combines with other muscles into the quadriceps tendon. 

5. All are supplied by the posterior branches of the femoral nerve. 

Reference(s)

R.M.H McMinn (1998). Last’s anatomy: regional and applied. Edinburgh: Churchill Livingstone.
Gray, H., Carter, H.V. and Davidson, G. (2017). Gray’s anatomy. London: Arcturus.