Which muscle has a long head origin at the ischial tuberosity and a short head origin at the lateral lip of linea aspera?

• A. Vastus Medialis
• B. Vastus Lateralis
• C. Biceps Femoris Long Head
• D. Biceps Femoris Short Head

Answer: (C)

The two-headed structure described is what defines the biceps femoris. One head (the long head) originates from the ischial tuberosity, while the other head (the short head) originates from the lateral lip of the linea aspera on the femur. These heads merge to insert at the fibular head and work together to flex the knee; the long head also helps extend the hip. So the muscle described is the biceps femoris as a whole, with its long and short heads arising from those two distinct sites. This distinguishes it from the quadriceps muscles like the vastus medialis and vastus lateralis, which originate from different parts of the femur and act to extend the knee, not flex it.