Upper Leg Anatomy

Semimembranosus Anatomy: Origin, Insertion, Action, Innervation

Semimembranosus Anatomy Study Origin: Upper outer quadrant of the posterior surface of the ischial tuberosity, deep to the conjoined tendon of the semitendinosus and the long head of the biceps femoris. Insertion: The posterior aspect of the medial condyle of tibia, below the joint line, sending fibers into the fascia over popliteal ligament. Action: Extension…

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Semitendinosus Anatomy: Origin, Insertion, Action, Innervation

Semitendinosus Anatomy Study Origin: Upper inner quadrant of the posterior surface of the ischial tuberosity, conjoined with the long head of biceps femoris Insertion: Upper part of the medial surface of the tibia, behind the attachment of the sartorius and distal and slightly anterior to the attachment of the gracilis. Action: Extension of the thigh at the hip,…

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Tensor Fasciae Latae Anatomy: Origin, Insertion, Action, Innervation

Tensor Fasciae Latae Anatomy Study Origin: Outer surface of the anterior iliac crest, between the tubercle of the iliac spine. A thick fascia covers the outer surface of the muscle, making it appear to be sandwiched between the layers of fasciae latae. Insertion:  By the iliotibial band anterior surface of the lateral condyle of the…

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Adductor Brevis Anatomy: Origin, Insertion, Action, Innervation

Adductor Brevis Anatomy Study Origin: Inferior ramus and body of the pubis, between gracilis and obturator externus. Insertion: Along a line from the lesser trochanter to the linea aspera, the upper third of the linea aspera, downward along the upper third of the linea aspera, immediately behind the pectineus and the upper part of adductor…

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Adductor Longus Anatomy: Origin, Insertion, Action, Innervation

Adductor Longus Anatomy Study Origin: Anterior surface of the pubis, in the angle between the crest and pubic symphysis. Insertion: Lower two-thirds of the medial lip of the linea aspera on the posterior surface. Action: Adduction of the thigh at the hip, assists with internal rotation of the thigh at the hip, assists with flexion of the thigh…

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Pectineus Anatomy: Origin, Insertion, Action, Innervation

Pectineus Anatomy Study Origin: Pectineal line of the pubis and a narrow area of the superior pubic ramus below it. Insertion: A vertical line from the lesser trochanter to the linea aspera Action: Assists with flexion of the thigh at the hip, assists with adduction of the thigh at the hip Innervation: Anterior division of…

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Rectus Femoris Anatomy: Origin, Insertion, Action, Innervation

 Rectus Femoris Anatomy Study: Origin, Insertion, Action and Innervation Origin: Straight head: from the anterior inferior iliac spine Reflected head: on a curved line along the upper part of the acetabulum at the ilium Insertion: The quadriceps tendon along with the three vasti muscles, enveloping the patella then by the patellar ligament into the tibial tuberosity.…

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Vastus Lateralis Anatomy: Origin, Insertion, Action, Innervation

Vastus Lateralis Anatomy Study Origin: Upper aspect of the intertrochanteric line, base of the greater trochanter and onto its anterior surface, from the proximal portion of the lateral lip of the linea aspera, lateral intermuscular septum Insertion: Into the lateral side of the quadriceps tendon, joining with rectus femoris and the other vasti muscles, enveloping the…

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Biceps Femoris Anatomy: Origin, Insertion, Action, Innervation

Biceps Femoris Anatomy Study Long head of Biceps Femoris:  Origin: Upper and inner surface of the posterior side of the ischial tuberosity, conjoined with semitendinosus Insertion: The main attachment is to the styloid process of the fibula, forming a semicircle around the lateral collateral ligament. The remainder splits into three laminae: the intermediate lamina fuses with the lateral…

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Vastus Medialis Anatomy: Origin, Insertion, Action, Innervation

Vastus Medialis Anatomy Study: Origin, Insertion, Action and Innervation Origin: Lower part of the intertrochanteric line, along the spiral line to the medial lip of the linea aspera and the medial intermuscular septum and the aponeurosis of adductor magnus. Insertion: Into the medial side of the quadriceps tendon joining with the rectus femoris and the other…

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Vastus Intermedius Anatomy: Origin, Insertion, Action, Innervation

Vastus Intermedius Anatomy Origin: Anterior and lateral aspects of the upper two-thirds of the femoral shaft and the lower part of the lateral intermuscular septum of the femur. Insertion: Into the quadriceps tendon along with rectus femoris and the other vasti muscles, enveloping the patella, then by the patellar ligament into the tibial tuberosity. Action:…

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Adductor Magnus Muscle Anatomy: Origin, Insertion, Action, Innervation

Adductor Magnus Muscle Anatomy Study Origin: Anterior: Inferior pubic ramus and the ramus of the ischium Posterior: Inferolateral aspect of the ischial tuberosity Insertion: Anterior: Medial margin of the gluteal tuberosity of the femur, medial to gluteus maximus. Posterior: By a broad attachment into the linea aspera and the proximal part of the medial supracondylar…

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Sartorius Muscle Anatomy: Origin, Insertion, Action, Innervation

Sartorius Muscle Anatomy Study Origin: Inferior portion of the anterior superior iliac spine Insertion: Upper medial surface of tibial shaft at the tibial flare Action: Assists with hip flexion, knee flexion, medial rotation of the knee, lateral rotation of the hip Innervation: Anterior division of the femoral nerve (L3- 4) Blood Supply: Branches from the…

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Gracilis Muscle Anatomy: Origin, Insertion, Actions and Innervation

Gracilis Muscle Anatomy Study Origin: Lower half of the body of the pubis, the inferior pubic ramus, and the adjoining part of the ischial ramus. Insertion: Upper part of the medial flare of the tibia, just below the medial condyle, proximal and slightly anterior to the attachment of the semitendinosus, and posterior and somewhat inferior to the attachment…

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