Glamour Girl With Beautiful Long Legs

- Thigh
The muscles of the thigh can be classified into three groups according to their location: anterior and posterior muscles and the adductors (on the medial side). All adductors except gracilis insert on the femur and therefore act only on the hip joint. The majority of the thigh muscles, the "true" thigh muscles, are insert on the leg (either the tibia or the fibula) and thus act primarily on the knee joint. Functionally, the extensors lie anteriorly on the thigh and are distinguished from flexors on the posterior side. Even though the sartorius flexes the knee, it is ontogenetically considered an extensor since its displacement is secondarily. Most of the adductors act exclusively on the hip joint, so functionally they qualify as hip muscles.
Of the anterior thigh muscles the largest are the four muscles of the quadriceps femoris: the central rectus femoris, which is surrounded by the three vasti, the vastus intermedius, medialis, and lateralis. Rectus femoris is attached to the pelvis with two tendons, while the vasti are inserted to the femur. All four muscles unite in a common tendon inserted into the patella from where the patellar ligament extends it down to the tibial tuberosity. Fibers from the medial and lateral vasti form two retinacula that stretch past the patella on either sides down to the condyles of the tibia. The quadriceps is the knee extensor, but the rectus femoris additionally flexes the hip joint, and articular muscle of the knee protects the articular capsule of the knee joint from being nipped during extension. The sartorius runs superficially and obliquely down on the anterior side of the thigh, from the anterior superior iliac spine to the pes anserinus on the medial side of the knee, from where it is further extended into the crural fascia. The sartorius acts as a flexor on both the hip and knee, but, due to its oblique course, also contributes to medial rotation of the leg as one of the pes anserinus muscles (with the knee flexed), and to lateral rotation of the hip joint.
There are four posterior thigh muscles. The biceps femoris has two heads: The long head has its origin on the ischial tuberosity together with the semitendinosus and acts on two joints. The short head originates from the middle third of the linea aspera on the shaft of the femur and the lateral intermuscular septum of thigh, and acts on only one joint. These two heads unite to form the biceps which inserts on the head of the fibula. The biceps flexes the knee joint and rotates the flexed leg laterally — it is the only lateral rotator of the knee and thus has to oppose all medial rotator. Additionally, the long head extends the hip joint. The semitendiosus and the semimembranosus share their origin with the long head of the biceps, and both attaches on the medial side of the proximal head of the tibia together with the gracilis and sartorius to form the pes anserinus. The semitendinosus acts on two joints; extension of the hip, flexion of the knee, and medial rotation of the leg. Distally, the semimembranosus' tendon is divided into three parts referred to as the pes anserinus profondus. Functionally, the semimembranosus is similar to the semitendinosus, and thus produces extension at the hip joint and flexion and medial rotation at the knee. Posteriorly below the knee joint, the popliteus stretches obliquely from the lateral femoral epicondyle down to the posterior surface of the tibia. The subpopliteal bursa is located deep to the muscle. Popliteus flexes the knee joint and medially rotates the leg.