[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Anatomy](https://durgical.com/en/anatomy/) › [Lower limb](https://durgical.com/en/anatomy/region/lower-limb/) › Rectus femoris [Muscular system](https://durgical.com/en/anatomy/system/muscular-system/) · [Lower limb](https://durgical.com/en/anatomy/region/lower-limb/) # Rectus femoris The rectus femoris is the middle muscle of the quadriceps at the front of the thigh; it straightens the knee and lifts the thigh. Official name: Rectus femoris muscle [See in 3D →](https://durgical.app/?from=durgipedia&lang=en#region=lower_limb&select=rectus_femoris&side=r) Opens in the Durgical app, no sign-up needed. ## What it is The middle of the four quadriceps muscles at the front of the thigh. It is the only one that starts on the [pelvis](https://durgical.com/en/anatomy/region/pelvis/), so it crosses both the hip and the knee. ## What it does Straightens the knee and helps lift the thigh (bend the hip), as in kicking. ## Key points - The only quadriceps head that crosses the hip, so hip extension with the knee bent stretches it fully: the basis of the Ely test - The quadriceps head most often strained; in adolescents the same sudden pull can avulse the apophysis of the anterior inferior iliac [spine](https://durgical.com/en/anatomy/region/spine/) - It emerges between the sartorius and the tensor fasciae latae below the anterior superior iliac spine (ASIS); the deep interval of the anterior hip approach lies between it and the [gluteus medius](https://durgical.com/en/anatomy/gluteus-medius-muscle/) ## Key facts **Origin** Straight head: anterior inferior iliac spine; reflected head: ilium above acetabulum **Insertion** Base of patella, then tibial tuberosity via [patellar ligament](https://durgical.com/en/anatomy/patellar-ligament/) **Action** Extends knee; flexes hip **Nerve** [Femoral nerve](https://durgical.com/en/anatomy/femoral-nerve/) (L2–L4) **Blood supply** Lateral circumflex femoral artery (descending branch) ## Relations **Superficial** At the top, the [sartorius](https://durgical.com/en/anatomy/sartorius-muscle/) and the [tensor fasciae latae](https://durgical.com/en/anatomy/tensor-fasciae-latae/), with the muscle appearing in the V between them; lower down only [fascia lata](https://durgical.com/en/anatomy/fascia-lata/) and [skin](https://durgical.com/en/anatomy/skin/) **Deep** [Vastus intermedius](https://durgical.com/en/anatomy/vastus-intermedius-muscle/) over most of its length; at its origin, the front of the hip [joint capsule](https://durgical.com/en/anatomy/articular-capsule-of-knee-joint/); the descending branch of the lateral circumflex [femoral artery](https://durgical.com/en/anatomy/femoral-artery/) runs under its lateral edge **Medial** [Vastus medialis](https://durgical.com/en/anatomy/vastus-medialis-muscle/) **Lateral** [Vastus lateralis](https://durgical.com/en/anatomy/vastus-lateralis-muscle/) **Below** Joins the vasti in the [quadriceps tendon](https://durgical.com/en/anatomy/tendon-of-quadriceps-femoris-muscle/) above the [patella](https://durgical.com/en/anatomy/patella/), where it forms the most superficial layer ## How to find it Lying supine, the person lifts the straightened leg a little off the couch: the spindle-shaped belly stands out down the middle of the front of the thigh, from the V between the sartorius and the tensor fasciae latae to the upper border of the patella. ## Examination - Ely test: prone, the examiner bends the knee passively; if the hip flexes and the buttock rises from the couch, the rectus femoris is tight - Modified Thomas test: with the opposite knee held to the [chest](https://durgical.com/en/anatomy/region/chest/) and the tested thigh resting on the couch, the knee swings into extension instead of staying bent near a right angle when the rectus femoris is short ## On imaging Ultrasound or MRI show the tendon of the reflected head running down inside the muscle belly; many strains centre on this intramuscular tendon, which is described when the injury is reported. ## Common problems - Strains (pulled muscle) from sprinting or kicking; bruising from a direct blow. - Weakness and shrinking after knee injury or surgery, which rehabilitation works to rebuild. ## How it is diagnosed Physical exam; ultrasound or MRI for significant injuries. ## Treatment - Rest, ice, then progressive strengthening with a physical therapist. ## Clinical notes - Smith-Petersen (anterior) approach to the hip: superficial interval between sartorius and tensor fasciae latae, deep interval between rectus femoris and gluteus medius; the reflected head may be released to reach the capsule - A pedicled rectus femoris flap, based on the descending branch of the lateral circumflex femoral artery, can cover groin and lower abdominal wall defects - With a femoral nerve lesion, knee extension fails: the knee gives way on stairs and slopes, and the patellar reflex is reduced ## Anatomical variants - A single straight head without a reflected head, and accessory slips toward the vastus lateralis, are described ## Development Like the rest of the quadriceps it comes from the dorsal muscle mass of the limb bud, hence its femoral nerve supply; the medial rotation of the [lower limb](https://durgical.com/en/anatomy/region/lower-limb/) in the seventh week turns this group to the front of the thigh. ## Related conditions - [Myoadenylate deaminase deficiency (AMP deaminase deficiency)](https://durgical.com/en/conditions/myoadenylate-deaminase-deficiency/) - [Marasmus](https://durgical.com/en/conditions/marasmus/) - [Falls in older adults](https://durgical.com/en/conditions/falls-in-older-adults/) - [Frailty syndrome](https://durgical.com/en/conditions/frailty-syndrome/) - [Sarcopenia](https://durgical.com/en/conditions/sarcopenia/) - [Soft tissue sarcomas (liposarcoma, leiomyosarcoma, rhabdomyosarcoma)](https://durgical.com/en/conditions/soft-tissue-sarcomas/) - [Inflammatory myopathies (dermatomyositis, polymyositis)](https://durgical.com/en/conditions/inflammatory-myopathies/) - [Patellar fracture](https://durgical.com/en/conditions/patellar-fracture/) ## Test yourself Think of the answer, then tap the question to see it. ## What makes the rectus femoris different from the other three quadriceps heads? It is the only quadriceps head that crosses the hip: its straight head arises from the anterior inferior iliac spine, so it flexes the hip as well as extending the knee. ## Which nerve supplies the rectus femoris, and from which roots? The femoral nerve (L2–L4). A femoral nerve lesion makes knee extension fail, so the knee gives way on stairs, and the patellar reflex is reduced. ## What does a positive Ely test show about the rectus femoris? Tightness of the rectus femoris: prone, the knee is bent passively and the hip flexes so the buttock rises, because the muscle crosses both hip and knee. ## Which avulsion can a sudden rectus femoris pull cause in an adolescent? Avulsion of the apophysis of the anterior inferior iliac spine, the origin of the straight head of the rectus femoris. ## In the Smith-Petersen anterior approach to the hip, which interval does the rectus femoris form? The deep interval, between the rectus femoris and the gluteus medius; the superficial interval lies between the sartorius and the tensor fasciae latae. [Add to my cards (5)](https://durgical.app/estudiar/?add=/en/anatomy/rectus-femoris-muscle/) Educational information, not medical advice. For any symptom, see a health professional. ## Its names **Official Latin (TA2)** musculus rectus femoris TA2 2614 **Official Spanish (DeCS)** Músculo recto femoral DeCS D052097 **English (TA2)** Rectus femoris muscle ## Related - [Vastus intermedius](https://durgical.com/en/anatomy/vastus-intermedius-muscle/) - [Femoral nerve](https://durgical.com/en/anatomy/femoral-nerve/) - [Femoral artery](https://durgical.com/en/anatomy/femoral-artery/) - [Circumflex femoral arteries](https://durgical.com/en/anatomy/medial-circumflex-femoral-artery/) - [Rectus femoris tendon](https://durgical.com/en/anatomy/tendon-of-rectus-femoris/) - [Hip bone](https://durgical.com/en/anatomy/hip-bone/) - [Patella](https://durgical.com/en/anatomy/patella/) - [Patellar tendon](https://durgical.com/en/anatomy/patellar-ligament/) Sources: Terminologia Anatomica (TA2); [DeCS](https://decs.bvsalud.org/es/ths/resource/?id=50351&filter=ths_termall&q=M%C3%BAsculo%20Cu%C3%A1driceps); [Anatomy, Abdomen and Pelvis, Rectus Femoris Muscle](https://www.ncbi.nlm.nih.gov/books/NBK539897/); [Anatomy, Bony Pelvis and Lower Limb: Thigh Quadriceps Muscle](https://www.ncbi.nlm.nih.gov/books/NBK513334/); [8.5 Development of the Appendicular Skeleton](https://openstax.org/books/anatomy-and-physiology-2e/pages/8-5-development-of-the-appendicular-skeleton) (OpenStax (Rice University), 2022) · adapted, [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/anatomy/rectus-femoris-muscle/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/anatomy/rectus-femoris-muscle/