Where does the piriformis insert?

Where does the piriformis insert?

• A. Greater trochanter
• B. Lesser trochanter
• C. Head of femur
• D. Intertrochanteric line

Answer: (A)

The main idea is where the piriformis attaches to the femur. The piriformis originates on the anterior surface of the sacrum, passes through the greater sciatic foramen, and inserts on the superior border of the greater trochanter. That placement on the upper edge of the greater trochanter is why the greater trochanter is the correct insertion site. The lesser trochanter is where the iliopsoas attaches, the head of the femur is the ball of the hip joint, and the intertrochanteric line is a bony ridge on the femur—not a muscle attachment for this muscle.

The main idea is where the piriformis attaches to the femur. The piriformis originates on the anterior surface of the sacrum, passes through the greater sciatic foramen, and inserts on the superior border of the greater trochanter. That placement on the upper edge of the greater trochanter is why the greater trochanter is the correct insertion site. The lesser trochanter is where the iliopsoas attaches, the head of the femur is the ball of the hip joint, and the intertrochanteric line is a bony ridge on the femur—not a muscle attachment for this muscle.