The iliacus is stretched with extension of the thigh at the hip joint.
Note: If the knee in back is excessively flexed, then the stretch will move over to the rectus femoris of the quadriceps femoris group.
![The iliacus is stretched with extension of the thigh at the hip joint.](https://learnmuscles.com/wp-content/uploads/2017/10/f07-19-A05170-1024x981.jpg)
The iliacus is stretched with extension of the thigh at the hip joint.