Popliteus muscle
| Popliteus muscle |
|---|
|
| Human calf muscles (popliteus muscle is the top muscle) |
| origin |
| Condylus lateralis femoris (outer joint head of the femur ) |
| approach |
| Upper posterior surface of the tibia |
| function |
| Knee flexion / extension, retraction of the lateral meniscus in the flexed knee, internal rotation of the lower leg or external rotation of the thigh |
| Innervation |
| Tibial nerve |
| Spinal segments |
| L4, L5 |
The popliteus muscle ( Latin for "popliteal muscle") is a skeletal muscle and lies in the deep flexor compartment of the lower leg . It is a small muscle that lies against the joint capsule from behind.
In some species, a sesamoid bone ( Os sesamoideum musculi poplitei ), which is also known as cyamella , is embedded in the tendon of origin of the muscle . This always occurs in cats , wet-nosed monkeys and marmosets , in dogs in around 80% of individuals and rarely in humans and other primates.
function
Although the popliteus muscle lies in the flexor box of the lower leg, it actually only has a flexing effect on the knee when the joint is already strongly flexed. In doing so, it pulls the posterior horn of the lateral meniscus backwards and protects it from entrapment. When the knee is almost straight, it has a weakly stretching effect on the joint due to its relationship to the flexion axis. Its most important function, however, is to cancel the final rotation of the knee by rotating the shinbone ( tibia ) inwards, or with the leg upright, the femur outwards against the tibia. The collateral ligaments are thus relaxed (relative to the situation with the knee extended) and the femoral head is reduced into the articular surface of the tibia, which enables the knee to flex.
See also
Individual evidence
- ^ PH McCarthy, AK Wood: Anatomical and radiological observations of the sesamoid bone of the popliteus muscle in the adult dog and cat. In: Anat Histol Embryol . 1989 Mar; 18 (1), pp. 58-65. PMID 2712335 .
- ^ JM Le Minor: Brief communication: the popliteal sesamoid bone (cyamella) in primates. In: Am J Phys Anthropol. 1992 Jan; 87 (1), pp. 107-110. PMID 1736668
- ↑ K. Franz: Fuss: An analysis of the popliteus muscle in man, dog, and pig with reconsideration of the general problems of muscle function . In: Anat Rec . 225, pp. 251-245 (1989).