Editing Human leg (section)

==== Thigh ====
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|+ Function of knee muscles<ref>Platzer (2004), p. 252</ref>
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! Movement !! Muscles<br />(in order of<br />importance)
|-
|Extension
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•[[Quadriceps|Quadriceps femoris]]<br />•[[Tensor fasciae latae muscle|Tensor fasciae latae]]*
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|Flexion
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•[[Semimembranosus muscle|Semimembranosus]]<br />•[[Semitendinosus muscle|Semitendinosus]]<br />•[[Biceps femoris muscle|Biceps femoris]]<br />•[[Gracilis muscle|Gracilis]]<br />•[[Sartorius muscle|Sartorius]]<br />•[[Popliteus muscle|Popliteus]]<br />•[[Gastrocnemius muscle|Gastrocnemius]]
|-
|Medial<br />rotation
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•Semimembranosus<br />•Semitendinosus<br />•Gracilis<br />•Sartorius<br />•Popliteus
|-
| Lateral<br />rotation
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•Biceps femoris<br />•Tensor fasciae latae*
|-
|colspan="2"|*Insignificant assistance.
|}
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 the adductors except gracilis insert on the femur and act on the hip joint, and so functionally qualify as hip muscles. The majority of the thigh muscles, the "true" thigh muscles, insert on the leg (either the tibia or the fibula) and act primarily on the knee joint. Generally, the extensors lie on anterior of the thigh and flexors lie on the posterior. Even though the sartorius flexes the knee, it is [[Ontogeny|ontogenetically]] considered an extensor since its displacement is secondary.<ref name="Platzer-232" />

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| footer = Anterior and posterior thigh muscles.
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Of the anterior thigh muscles the largest are the four muscles of the [[Quadriceps femoris muscle|quadriceps femoris]]: the central [[Rectus femoris muscle|rectus femoris]], which is surrounded by the three vasti, the [[Vastus intermedius muscle|vastus intermedius]], [[Vastus medialis muscle|medialis]], and [[Vastus lateralis muscle|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 [[Lateral retinaculum|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 muscle|sartorius]] runs superficially and obliquely down on the anterior side of the thigh, from the [[anterior superior iliac spine]] to the [[pes anserinus (leg)|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.<ref>Platzer (2004), p. 248</ref>

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 [[Semitendinosus muscle|semitendinosus]] and the [[Semimembranosus muscle|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.<ref>Platzer (2004), p. 250</ref> Posteriorly below the knee joint, the [[Popliteus muscle|popliteus]] stretches obliquely from the [[lateral epicondyle of the femur|lateral femoral epicondyle]] down to the posterior surface of the tibia. The [[subpopliteal recess|subpopliteal bursa]] is located deep to the muscle. Popliteus flexes the knee joint and medially rotates the leg.<ref name="Platzer 2004, p 264">Platzer (2004), p. 264</ref>
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