The rectus femoris muscle originates from the anterior superior iliac spine and inserts into the tibial tuberosity. Predict its main actions with only this information.

Video transcript

Hi, everyone. Let's take a look at this practice problem together. Which of the following quadriceps, femoris muscles crosses the hip joint. The answer options are a vastus medialis, B, Rectus, Voris C, vastus lateralis and D vastus intermedius. So recall that the quadriceps for Morris muscles is made up of four muscles and those are the ones that are listed in our answer options. Now, the function of the quadriceps for Morris is knee extension and hip flexion and all four muscles of the quadriceps for Morris are involved in knee extension. However, only one is responsible for hip flexion and that's because it crosses the hip joint. So which muscle is that? Well? Option. A vastus medialis. This originates from the medial side of the femur. Option C vastus lateralis is the muscle that originates from the lateral side of the femur. Option D vastus intermedius. This muscle lies between vastus medialis and vastus lateralis. So it originates on the front of the femur. The only muscle that crosses the hip joint is the rectus femoris. The rectus femoris originates on the ilium and thus crosses that hip joint. So the correct answer is option B, rectus for Morris. All right, everyone. I hope you found this helpful and I'll see you soon for the next practice problem.