Rectus femoris muscle
Encyclopedia
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 parts of the quadriceps muscle attach to the patella (knee cap) via the quadriceps tendon.
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
.
.
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.
The rectus femoris and sartorius
are the only muscles in the quadriceps group that are involved in flexion of the hip, since they are the only ones that originate in the pelvis
and not the femur
. By crossing the pelvic femoral joint they can act as a lever to flex the leg at the hip.
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.
In the other extreme, the muscle's ability to flex the hip and extend can be compromised in a position of full hip extension and knee flexion, due to passive insufficiency.
The rectus femoris is considered a direct antagonist
to the hamstring
s. The hamstrings oppose the rectus femoris at the hip joint through extension and at the knee joint through flexion. The rectus femoris can be torn which can be very painful.
Human body
The human body is the entire structure of a human organism, and consists of a head, neck, torso, two arms and two legs.By the time the human reaches adulthood, the body consists of close to 100 trillion cells, the basic unit of life...
. The others are the vastus medialis
Vastus medialis
The vastus medialis , often called the 'teardrop' muscle, is a medially located muscle of the quadriceps.-Function:The vasti appear to act largely in a co-ordinated manner throughout the control of knee extension...
, the vastus intermedius
Vastus intermedius muscle
The Vastus intermedius arises from the front and lateral surfaces of the body of the femur in its upper two-thirds, sitting under Rectus Femoris and from the lower part of the lateral intermuscular septum...
(deep to the rectus femoris), and the vastus lateralis
Vastus lateralis muscle
The Vastus lateralis is the largest part of the Quadriceps femoris. It arises by a broad aponeurosis, which is attached to the upper part of the intertrochanteric line, to the anterior and inferior borders of the greater trochanter, to the lateral lip of the gluteal tuberosity, and to the upper...
. All four parts of the quadriceps muscle attach to the patella (knee cap) via the quadriceps tendon.
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
Bipennate muscle
A modification of the unipennate condition is found where oblique fibers converge to both sides of a central tendon; these are called bipennate. Bipennate muscle is stronger than unipennate - it shortens less than unipennate muscles but develops greater tension when it does...
manner, the deep fibers running straight down to the deep aponeurosis
Aponeurosis
Aponeuroses are layers of flat broad tendons. They have a shiny, whitish-silvery color, are histologically similar to tendons, and are very sparingly supplied with blood vessels and nerves. When dissected, aponeuroses are papery, and peel off by sections...
.
Origin and insertion
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 acetabulumAcetabulum
The acetabulum is a concave surface of the pelvis. The head of the femur meets with the pelvis at the acetabulum, forming the hip joint.-Structure:...
.
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.
The rectus femoris and sartorius
Sartorius muscle
The Sartorius muscle – the longest muscle in the human body – is a long thin muscle that runs down the length of the thigh. Its upper portion forms the lateral border of the femoral triangle.-Origin and insertion:...
are the only muscles in the quadriceps group that are involved in flexion of the hip, since they are the only ones that originate in the pelvis
Pelvis
In human anatomy, the pelvis is the lower part of the trunk, between the abdomen and the lower limbs .The pelvis includes several structures:...
and not the femur
Femur
The femur , or thigh bone, is the most proximal bone of the leg in tetrapod vertebrates capable of walking or jumping, such as most land mammals, birds, many reptiles such as lizards, and amphibians such as frogs. In vertebrates with four legs such as dogs and horses, the femur is found only in...
. By crossing the pelvic femoral joint they can act as a lever to flex the leg at the hip.
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
Iliacus muscle
The iliacus is a flat, triangular muscle which fills the iliac fossa.- Course :The iliacus arises from the iliac fossa on the interior side of the hip bone, and also from the region of the anterior inferior iliac spine...
, psoas major
Psoas major muscle
-External links: - "Posterior Abdominal Wall: Muscles of the Posterior Abdominal Wall"* *...
, tensor fasciae latae, and the remaining hip flexors
Hip flexors
In human anatomy, the hip flexors are a group of skeletal muscles that act to flex the femur onto the lumbo-pelvic complex, i.e., pull the knee upward....
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 lateralis muscle
The Vastus lateralis is the largest part of the Quadriceps femoris. It arises by a broad aponeurosis, which is attached to the upper part of the intertrochanteric line, to the anterior and inferior borders of the greater trochanter, to the lateral lip of the gluteal tuberosity, and to the upper...
, vastus medialis
Vastus medialis
The vastus medialis , often called the 'teardrop' muscle, is a medially located muscle of the quadriceps.-Function:The vasti appear to act largely in a co-ordinated manner throughout the control of knee extension...
, and vastus intermedius
Vastus intermedius muscle
The Vastus intermedius arises from the front and lateral surfaces of the body of the femur in its upper two-thirds, sitting under Rectus Femoris and from the lower part of the lateral intermuscular septum...
, and less by the rectus femoris.
In the other extreme, the muscle's ability to flex the hip and extend can be compromised in a position of full hip extension and knee flexion, due to passive insufficiency.
The rectus femoris is considered a direct antagonist
Antagonist (muscle)
Most muscles work in pairs, and when a muscle works it needs to have an agonist and an antagonist, unless the muscle's natural state is opposite to that which is produced by the muscle, example Sphincter ani externus muscle....
to the hamstring
Hamstring
In human anatomy, the hamstring refers to any one of the three posterior thigh muscles, or to the tendons that make up the borders of the space behind the knee. In modern anatomical contexts, however, they usually refer to the posterior thigh muscles, or the tendons of the semitendinosus, the...
s. The hamstrings oppose the rectus femoris at the hip joint through extension and at the knee joint through flexion. The rectus femoris can be torn which can be very painful.