RECTUS FEMORIS Why does rectus femoris, one of your quads, matter so much when it comes to back pain?Your quadriceps are comprised of four muscles, three of them, vastus medialis, intermedius and lateralis act exclusively to extend the knee - his is because the vastus group only cross the knee, a muscle that only crosses one joint is known as monoarticulate.The fourth quad, rectus femoris, is biarticulate, or it crosses both the hip and the knee and acts to extend the leg as well as being one of

The rectus femoris is a fusiform and biarticular long muscle located in the anterior aspect of the quadriceps muscle, these types of muscles are designed to execute movements that require significant length change or high shortening velocity. This biarticulate muscle is innervated by the femoral nerve and has two heads of origin: the direct or straight head, which arises from the anterior inferior iliac spine, and the indirect or reflected head, which arises from the superior acetabular ridge. T