Editing Hamstring (section)

==Structure==
The three muscles of the posterior thigh (semitendinosus, semimembranosus, biceps femoris) [[Flexion|flex]] (bend) the knee, while all but the biceps femoris [[Extension (kinesiology)|extend]] (straighten) the hip. The three 'true' hamstrings cross both the hip and the knee joint and are therefore involved in knee flexion and hip extension. The short head of the biceps femoris crosses only one joint (knee) and is therefore not involved in hip extension. With its divergent origin and innervation, it is sometimes excluded from the 'hamstring' characterization.<ref name="norman">{{NormanAnatomy|postthigh}}</ref>

{| class="wikitable"
|-
| '''Muscle''' || '''Origin''' || '''Insertion''' || '''Nerve'''
|-
| [[semitendinosus]] || [[ischial tuberosity]] || medial surface of [[tibia]] || tibial part of [[sciatic nerve|sciatic]]
|-
| [[semimembranosus]] || ischial tuberosity || [[medial tibial condyle]] || tibial part of [[sciatic nerve|sciatic]]
|- 	
| [[biceps femoris]] - long head || ischial tuberosity || lateral side of the [[head of the fibula]] || tibial part of [[sciatic nerve|sciatic]]
|-
| [[biceps femoris]] -  short head || [[linea aspera]] and [[lateral supracondylar line of femur]] ||  lateral side of the [[head of the fibula]] (common tendon with the long head) || [[common peroneal nerve|common peroneal]]
|}

A portion of the [[adductor magnus]] is sometimes considered a part of the hamstrings.<ref name="norman" />
[[File:Gray434.png|thumb|150px|Biceps femoris, semitendinosus and semimembranosus muscles of the right leg]]