​​Which of the following muscles flexes the thigh, but also laterally flexes the vertebral column when its origin and insertion switch?

a. Sartorius muscle

b. Psoas major muscle

c. Iliacus muscle

d. Rectus abdominis muscle

Video transcript

Hi, everyone. Let's take a look at this practice problem together. The psoas major is a muscle of the. The answer options are a anterior abdominal wall, b, posterior abdominal wall c, accessory muscle of respiration and d anterior arm. To answer this question, let's recall both the origin and insertion of the. So a major recall that the psoas major originates from vertebrae T 12 through L five. So its origin is in the lumbar spine region. It then runs downward and joins the iliacus muscle in the thigh to form Ileos soas its insertion is on the lesser tranter of the femur. It's a long muscle that spans from the lumbar spine to the femur. So it has many actions and those actions include hip flexion, core stabilization, trunk, bending, and lateral spine rotation. So, out of our answer options, it's not an anterior abdominal wall muscle, it's not a respiratory accessory muscle and it is not located on the anterior arm. So answers AC and D are incorrect. The psoas major is a muscle of the posterior abdominal wall. The correct answer is option B, posterior abdominal wall. All right, everyone. I hope you found this helpful and I'll see you soon for the next practice problem.