State the origins, insertion, and primary actions of the gluteus maximus.

• A. Origins: anterior ilium; sacrum; coccyx; insertion: gluteal tuberosity of the femur and IT band. Action: extends and laterally rotates the thigh; some fibers assist in abduction/adduction.
• B. Origins: posterior ilium, sacrum, and coccyx; sacrotuberous and iliotibial band. Insertion: gluteal tuberosity of the femur and IT band. Action: extends and laterally rotates the thigh; some fibers assist in abduction/adduction.
• C. Origins: external surface of the ilium. Insertion: greater trochanter. Action: abducts the thigh.
• D. Origins: sacrum; Insertion: lesser trochanter; Action: flexes thigh.

Answer: (B)