Template:Infobox Muscle WikiDoc Resources for Rectus femoris muscle Articles Most recent articles on Rectus femoris muscle Most cited articles on Rectus femoris muscle Review articles on Rectus femoris muscle Articles on Rectus femoris muscle in N Eng J Med, Lancet, BMJ Media Powerpoint slides on Rectus femoris muscle Images of Rectus femoris muscle Photos of Rectus femoris muscle Podcasts & MP3s on Rectus femoris muscle Videos on Rectus femoris muscle Evidence Based Medicine Cochrane Collaboration on Rectus femoris muscle Bandolier on Rectus femoris muscle TRIP on Rectus femoris muscle Clinical Trials Ongoing Trials on Rectus femoris muscle at Clinical Trials.gov Trial results on Rectus femoris muscle Clinical Trials on Rectus femoris muscle at Google Guidelines / Policies / Govt US National Guidelines Clearinghouse on Rectus femoris muscle NICE Guidance on Rectus femoris muscle NHS PRODIGY Guidance FDA on Rectus femoris muscle CDC on Rectus femoris muscle Books Books on Rectus femoris muscle News Rectus femoris muscle in the news Be alerted to news on Rectus femoris muscle News trends on Rectus femoris muscle Commentary Blogs on Rectus femoris muscle Definitions Definitions of Rectus femoris muscle Patient Resources / Community Patient resources on Rectus femoris muscle Discussion groups on Rectus femoris muscle Patient Handouts on Rectus femoris muscle Directions to Hospitals Treating Rectus femoris muscle Risk calculators and risk factors for Rectus femoris muscle Healthcare Provider Resources Symptoms of Rectus femoris muscle Causes & Risk Factors for Rectus femoris muscle Diagnostic studies for Rectus femoris muscle Treatment of Rectus femoris muscle Continuing Medical Education (CME) CME Programs on Rectus femoris muscle International Rectus femoris muscle en Espanol Rectus femoris muscle en Francais Business Rectus femoris muscle in the Marketplace Patents on Rectus femoris muscle Experimental / Informatics List of terms related to Rectus femoris muscle ## Contents * 1 Overview * 2 Origin and insertion * 3 Functions * 4 Additional images * 5 External links ## Overview[edit | edit source] The Rectus femoris muscle is one of the four quadriceps muscles of the human body. (The others are the vastus medialis, the vastus intermedius (deep to the rectus femoris), and the vastus lateralis. All four combine to form the quadriceps tendon, which inserts into the patella and continues as the patellar ligament.) The Rectus femoris is situated in the middle of the front of the thigh; it is fusiform in shape, and its superficial fibers are arranged in a bipenniform manner, the deep fibers running straight down to the deep aponeurosis. ## Origin and insertion[edit | edit source] It arises by two tendons: one, the anterior or straight, from the anterior inferior iliac spine; the other, the posterior or reflected, from a groove above the brim of the acetabulum. The two unite at an acute angle, and spread into an aponeurosis which is prolonged downward on the anterior surface of the muscle, and from this the muscular fibers arise. The muscle ends in a broad and thick aponeurosis which occupies the lower two-thirds of its posterior surface, and, gradually becoming narrowed into a flattened tendon, is inserted into the base of the patella. ## Functions[edit | edit source] * Hip Flexion * Knee Extension The rectus femoris is the only muscle in the quadriceps group that is involved in hip flexion, since it is the only one that originates in the pelvis and not the femur. The rectus femoris is a weaker hip flexor when the knee is extended because it is already shortened and thus suffers from active insufficiency. In essence: the action of raising a straightened leg will recruit more iliacus, psoas major, tensor fasciae latae, and the remaining hip flexors than it will the rectus femoris. Similarly, the rectus femoris is not dominant in knee extension when the hip is flexed since it is already shortened and thus suffers from active insufficiency. In essence: the action of extending a leg from a seated position is primarily driven by the vastus lateralis, vastus medialis, and vastus intermedius, and less by the rectus femoris. The rectus femoris is considered a direct antagonist to the hamstrings. The hamstrings oppkjuose the rectus femoris at the hip joint through extension and at the knee joint through flexion. Simultaneous contraction of the rectus femoris and hamstrings results in simultaneous hip and knee extension due to leverage (Lombard's Paradox.) ## Additional images[edit | edit source] * Structures surrounding right hip-joint. * Cross-section through the middle of the thigh. * The femoral artery. * Nerves of the right lower extremity. Front view. ## External links[edit | edit source] * Template:MuscleLoyola * Template:GPnotebook * Template:ViennaCrossSection * PTCentral Template:Gray's Template:Muscles of lower limb Template:WH Template:WS