Final answer:
The Tensor fasciae latae muscle originates from the iliac crest and inserts onto the iliotibial tract. Its action is to flex and abduct the thigh and stabilize the lateral aspect of the knee.
Step-by-step explanation:
The Tensor fasciae latae muscle originates from the iliac crest and the anterior superior iliac spine of the pelvis. It inserts onto the iliotibial tract, a thick band of connective tissue on the lateral aspect of the thigh that extends to the tibia.
The action of the Tensor fasciae latae is to flex and abduct the thigh, working in synergy with the gluteus medius and iliopsoas muscles. It also helps to stabilize the lateral aspect of the knee by pulling on the iliotibial tract, making it taut.