Beginners Rectus Femoris Muscle in the Quadriceps By Elizabeth Quinn Elizabeth Quinn Elizabeth Quinn is an exercise physiologist, sports medicine writer, and fitness consultant for corporate wellness and rehabilitation clinics. Learn about our editorial process Updated on June 30, 2020 Medically reviewed by Erin Pereira, PT, DPT Medically reviewed by Erin Pereira, PT, DPT on June 17, 2020 LinkedIn Erin Pereira, PT, DPT, is a board-certified clinical specialist in orthopedic physical therapy. Learn about our Medical Review Board Print MedicalRF.com / Getty Images Table of Contents View All Table of Contents Anatomy What It Does Injuries Exercises The rectus femoris muscle is one of the four quadriceps muscles. It is located in the middle of the front of the thigh. It is responsible for knee extension and hip and thigh flexion. It is the main muscle that can flex the hip. Anatomy The rectus femoris attaches from the pelvis to just below the knee joint (the patellar tendon). The other muscles of the quadriceps include the vastus medialis, the vastus intermedius, and the vastus lateralis. The rectus femoris muscle has two heads. The straight (direct) head has its origin on the anterior inferior iliac spine. The reflected head has its origin on the ilium, above the acetabulum. It has its insertion into the patellar tendon at the patella of the knee. It is fed by a descending branch of the lateral femoral circumflex artery. It is innervated by the femoral nerve. What It Does In sports, the rectus femoris is used powerfully when you kick a football or soccer ball. It is also used in cycling. It is considered one of the muscles that make up the hip flexors; a group of muscles that bring the legs and trunk together in a flexion movement. The muscles that make up the hip flexors include: Psoas major Illiacus Rectus femoris Pectineus Sartorius It also extends the leg at the knee. It can extend the knee powerfully when the hip is extended. But if the hip is flexed, such as when you are sitting, it is weaker in extending the knee and the other quads have to do the work. The same is true if the knee is extended; in that case, it can only flex the hip weakly and the other hip flexors have to go to work. The synergist muscles for the rectus femoris are the gluteus maximus, piriformis, obturator externus, obturator internus, and the superior and inferior gemelli. The hamstrings are the antagonist muscles to the rectus femoris. They produce the opposite action. Injuries You can have a strain by overuse of the rectus femoris in sprinting or kicking, and you may feel pain in the groin. You may also feel pain when walking downstairs. Acute tears or strains can happen in activities such as jumping, sprinting or kicking, and these usually happen at the patellar tendon. You might feel a sharp pain extending to the knee or be unable to fully straighten the knee. Sitting too much can tighten and shorten the hip flexors, as can wearing high heel shoes. Enjoying running and fitness walking develops the hamstrings, the antagonist muscles to the rectus femoris, and you can have a relative imbalance if those are your chief physical activities. Exercises for the Rectus Femoris Squats and lunges, both simply with your body weight or with barbell or dumbbells will exercise the rectus femoris. Machine exercises include the leg extension and upright leg press. If your chief cardio activities are walking or running, it is good to include exercises for the quads in the rest of your fitness program. Was this page helpful? Thanks for your feedback! Get exercise tips to make your workouts less work and more fun. Sign Up You're in! Thank you, {{form.email}}, for signing up. There was an error. Please try again. What are your concerns? Other Inaccurate Hard to Understand Submit 9 Sources Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Landin D, Thompson M, Reid M. Actions of Two Bi-Articular Muscles of the Lower Extremity: A Review. J Clin Med Res. 2016;8(7):489-94. doi:10.14740/jocmr2478w Grob K, Manestar M, Filgueira L, Ackland T, Gilbey H, Kuster MS. New insight in the architecture of the quadriceps tendon. J Exp Orthop. 2016;3(1):32. doi:10.1186/s40634-016-0068-y Ryan JM, Harris JD, Graham WC, Virk SS, Ellis TJ. Origin of the direct and reflected head of the rectus femoris: an anatomic study. Arthroscopy. 2014;30(7):796-802. doi:10.1016/j.arthro.2014.03.003 Page BJ, Mrowczynski OD, Payne RA, et al. The Relative Location of the Major Femoral Nerve Motor Branches in the Thigh. Cureus. 2019;11(1):e3882. doi:10.7759/cureus.3882 Suehiro T, Mizutani M, Okamoto M, et al. Influence of Hip Joint Position on Muscle Activity during Prone Hip Extension with Knee Flexion. J Phys Ther Sci. 2014;26(12):1895-8. doi:10.1589/jpts.26.1895 Yoo S, Dedova I, Pather N. An appraisal of the short lateral rotators of the hip joint. Clin Anat. 2015;28(6):800-12. doi:10.1002/ca.22568 American Academy of Orthopedic Surgeons. Patellar Tendon Tear. Daly C, Persson UM, Twycross-lewis R, Woledge RC, Morrissey D. The biomechanics of running in athletes with previous hamstring injury: A case-control study. Scand J Med Sci Sports. 2016;26(4):413-20. doi:10.1111/sms.12464 Ema R, Sakaguchi M, Akagi R, Kawakami Y. Unique activation of the quadriceps femoris during single- and multi-joint exercises. Eur J Appl Physiol. 2016;116(5):1031-41. doi:10.1007/s00421-016-3363-5 Additional Reading Zhu XF, Zhang XC. Clinical anatomy and mechanical tensile properties of the rectus femoris tendon. 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