From Surf Wiki (app.surf) — the open knowledge base

Third trochanter

Common but unusual feature of the human femur

Field	Value
Name	Third trochanter
Latin	trochanter tertius
Image	Third trochanter-tweaked.png
Caption	Human femoral bones featuring third trochanters
Image2	Superior_epiphysis_-_posterior_view.jpg
Caption2	Human right femur. Posterior view, featuring third trochanter

In human anatomy, the third trochanter is a bony projection occasionally present on the proximal femur near the superior border of the gluteal tuberosity. When present, it is oblong, rounded, or conical in shape and sometimes continuous with the gluteal ridge. It generally occurs bilaterally without significant side to side dimorphism. A structure of minor importance in humans, the incidence of the third trochanter varies from 17 to 72% between ethnic groups and it is frequently reported as more common in females than in males. Structures analogous to the third trochanter are present in other mammals, including some primates, but also in horses. It is called the third trochanter in reference to the greater and lesser trochanters that are always present on the femur.

Function

Its function is to provide an attachment for the ascending tendon of the gluteus maximus muscle. It may function as (1) a reinforcement mechanism for the proximal femoral diaphysis in response to increased ground reaction force and (2) to increase the attachment surface area for the gluteal musculature and thereby providing greater efficiency of contracture. Mechanical load from the gluteus maximus may, on the other hand, affect the morphology of the proximal femur, similar to how quadriceps determines the size and shape of the tibial tuberosity, and thereby the shape of the third trochanter. However, no certain conclusions regarding the biomechanical role of the third trochanter can be made.

Anthropology

The third trochanter is associated with short, robust femora, and is frequently present and well developed in Neanderthals (that were shorter and more robust than anatomically modern humans) but generally absent in higher primates.

Studying fossils of Ardipithecus ramidus (a chimpanzee–human last common ancestor candidate), noted that in this species—as well as in Proconsul, Nacholapithecus, and Dryopithecus (Miocene primates)—homologs to the third trochanter and the hypotrochanteric fossa are present while both traits are absent in extant apes. They concluded that the hominid morphotype is primitive and the femoral shape of apes is derived contrary to what was previously thought.

Notes

References

{{cite journal
{{cite journal
{{cite journal

References

{{harvnb. Lozanoff. Sciulli. Schneider. 1985
{{harvnb. Bolanowski. Śmiszkiewicz-Skwarska. Polguj. Jędrzejewski. 2005
[[:de:Hermann_Braus. Hermann Braus]], [[:de:Curt_Elze. Curt Elze]]: ''Anatomie des Menschen. Ein Lehrbuch für Studierende und Ärzte. Erster Band. Bewegungsapparat''. 3. Auflage. Julius Springer, Berlin 1954. [https://digi.ub.uni-heidelberg.de/diglit/braus1921bd1 Digitalisat der Universität Heidelberg]. S. 464.
(2018). "Trochanter tertius incidence in a Bulgarian population". Science & Technologies.
In modern humans, the gluteal tuberosity is occasionally replaced by a shallow groove known as the hypotrochanteric fossa. In some cases, this fossa coexists with the third trochanter.
{{harvnb. Lovejoy. Suwa. Spurlock. Asfaw. 2009

Info: Wikipedia Source

This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page.

bones-of-the-lower-limb femur

Want to explore this topic further?

Ask Mako anything about Third trochanter — get instant answers, deeper analysis, and related topics.

Research with Mako

Free with your Surf account

Content sourced from Wikipedia, available under CC BY-SA 4.0.

This content may have been generated or modified by AI. CloudSurf Software LLC is not responsible for the accuracy, completeness, or reliability of AI-generated content. Always verify important information from primary sources.

Report