Hamstring 232867 224473763 2008-07-09T00:19:04Z Bobo192 97951 Reverted edits by [[Special:Contributions/86.142.97.23|86.142.97.23]] ([[User talk:86.142.97.23|talk]]) to last version by 79.66.136.77 {{Infobox Muscle | Name = {{PAGENAME}} | Latin = | GraySubject = 128 | GrayPage = 478 | Image = Gray1239.png | Caption = Back of left lower extremity. | Caption2 = Interior muscular view of the three muscles that make up the hamstring| Origin = [[tuberosity of the ischium]], [[linea aspera]] | Insertion = [[tibia]], [[fibula]] | Blood = [[inferior gluteal artery]], [[profunda femoris artery]] | Nerve = [[sciatic nerve]], [[tibial nerve]]<ref>[http://www.gla.ac.uk/ibls/fab/tutorial/anatomy/knee1.html University of Glasgow :: Biomedical & Life Sciences :: Biomedical & Life Sciences<!-- Bot generated title -->]</ref> | Action = [[flexion]] of [[knee]] | Antagonist = [[Rectus femoris muscle]] | DorlandsPre = h_02 | DorlandsSuf = 12407578 | }} In [[human anatomy]], a '''hamstring''' refers to one of the [[tendon]]s that make up the borders of the space behind the knee. In modern anatomical contexts, however, they usually refer to the tendons of the [[semitendinosus]], the [[semimembranosus]], and the [[biceps femoris]]. In quadrupeds, it refers to the single large tendon found behind the knee or comparable area. As shown in the diagram, the human hamstring occupies the posterior of the body of the [[femur]]. == Etymology == The word ''ham'' originally referred to the fat and muscle behind the [[knee]]. ''String'' refers to tendons, and thus, the hamstrings are the string-like tendons felt on either side of the back of the knee, the long muscle. The three muscles of the posterior [[thigh]] (semitendinosus, semimembranosus, biceps femoris) [[Flexion|flex]] (bend) the knee, while three of the four [[Extension (kinesiology)|extend]] (straighten) the hip. The short head of the biceps femoris, with its divergent origin and innervation, is not involved in hip extension, and thus is sometimes excluded from the 'hamstring' characterization. <ref>{{NormanAnatomy|postthigh}}</ref> {| class="wikitable" | '''Muscle''' || '''Origin''' || '''Insertion''' || '''Nerve''' |- | [[semitendinosus]] || [[ischial tuberosity]] || medial surface of [[tibia]] || [[tibial nerve|tibial]] |- | [[semimembranosus]] || ischial tuberosity || [[medial tibial condyle]] || [[tibial nerve|tibial]] |- | [[biceps femoris]] - long head || ischial tuberosity || lateral side of the [[head of the fibula]] || [[tibial nerve|tibial]] |- | [[biceps femoris]] - short head || [[linea aspera]] near the [[head of the femur]] || lateral side of the [[head of the fibula]] (common tendon with the long head) || [[common fibular nerve|common fibular]] |} A portion of the [[adductor magnus]] is sometimes considered a part of the hamstrings.<ref>{{NormanAnatomy|postthigh}}</ref> ==Functions== The hamstrings cross and act upon two joints - the [[hip]] and the [[knee]]. Semitendinosus and semimembranosus extend the hip when the trunk is fixed or extend the trunk when the hip is fixed; they also flex the knee and medially (inwardly) rotate the lower leg when the knee is bent. The long head of the biceps femoris extends the hip as when beginning to walk; both short and long heads flex the knee and laterally (outwardly) rotates the lower leg when the knee is bent.a push from the hamstring will help you jump higher The hamstrings play a crucial role in many daily activities, such as, walking, running, jumping, and controlling some movement in the trunk. In walking, they are most important as an [[antagonist (muscle)|antagonist]] to the [[quadriceps]] in the deceleration of knee extension. ==Injuries== [[Muscle strain|Straining]] of the hamstring, also known as a [[pulled hamstring]], is defined as an excessive stretch or tear of muscle fibers and related tissues. ==Use in surgery== The distal semitendinosis tendon is one of the tendons that can be used in the [[surgery|surgical procedure]] [[anterior cruciate ligament reconstruction|ACL reconstruction]]. In this procedure, a piece of it is used to replace the [[anterior cruciate ligament]] (ACL). The ACL is one of the four major ligaments in the knee. == See also == * [[Popliteal fossa]] * [[Lombard's Paradox]] == References == {{reflist}} == External links == * [http://www.harkema.ucla.edu/hamstring.jpg Illustration at ucla.edu] * {{eMedicineDictionary|Hamstring}} {{Muscles of lower limb}} [[Category:Muscular system]] [[he:שרירי מיתר הברך]] [[nl:Hamstrings]] [[zh:腿後腱]]