Limits...
Morphometric and statistical analysis of the palmaris longus muscle in human and non-human primates.

Aversi-Ferreira RA, Bretas RV, Maior RS, Davaasuren M, Paraguassú-Chaves CA, Nishijo H, Aversi-Ferreira TA - Biomed Res Int (2014)

Bottom Line: The palmaris longus is considered a phylogenetic degenerate metacarpophalangeal joint flexor muscle in humans, a small vestigial forearm muscle; it is the most variable muscle in humans, showing variation in position, duplication, slips and could be reverted.It is frequently studied in papers about human anatomical variations in cadavers and in vivo, its variation has importance in medical clinic, surgery, radiological analysis, in studies about high-performance athletes, in genetics and anthropologic studies.Hypothetically, the comparison of the relative length of tendons and belly could indicate the pathway of the degeneration of this muscle, that is, the degeneration could be associated to increased tendon length and decreased belly from more primitive primates to those most derivate, that is, great apes to modern humans.

View Article: PubMed Central - PubMed

Affiliation: Department of Anatomy, Howard University College of Medicine, 520 W Street NW, Numa Adams Building, Washington, DC 20059, USA ; Laboratory of Primate Anthropology, Biochemistry, Neurosciences and Behavior, Federal University of Tocantins, NS 15 Avenue, Block 109 Norte, Plano Diretor Norte, 77001-090 Palmas, TO, Brazil ; Graduate School of Animal Biology, Institute of Biology, University of Brasilia, Darcy Ribeiro Campus, 70910-900 Brasília, DF, Brazil ; Department of Physiology, Laboratory of Neuroscience and Behavior, University of Brasilia, Darcy Ribeiro Campus, 70910-900 Brasília, DF, Brazil.

ABSTRACT
The palmaris longus is considered a phylogenetic degenerate metacarpophalangeal joint flexor muscle in humans, a small vestigial forearm muscle; it is the most variable muscle in humans, showing variation in position, duplication, slips and could be reverted. It is frequently studied in papers about human anatomical variations in cadavers and in vivo, its variation has importance in medical clinic, surgery, radiological analysis, in studies about high-performance athletes, in genetics and anthropologic studies. Most studies about palmaris longus in humans are associated to frequency or case studies, but comparative anatomy in primates and comparative morphometry were not found in scientific literature. Comparative anatomy associated to morphometry of palmaris longus could explain the degeneration observed in this muscle in two of three of the great apes. Hypothetically, the comparison of the relative length of tendons and belly could indicate the pathway of the degeneration of this muscle, that is, the degeneration could be associated to increased tendon length and decreased belly from more primitive primates to those most derivate, that is, great apes to modern humans. In conclusion, in primates, the tendon of the palmaris longus increase from Lemuriformes to modern humans, that is, from arboreal to terrestrial primates and the muscle became weaker and tending to be missing.

Show MeSH

Related in: MedlinePlus

Photos of the forearms of (a) Propithecus sp. (0.45x, left); (b) Lemur catta (0.52x, left); (c) Sapajus libidinosus (0.34x, right); (d) Ateles sp. (0.1x, right); (e) Callithrix sp. (0.3x, right); (f) Aotus sp. (0.8x, right); (g) Macaca fuscata (0.34x, right); (h) Pongo sp. (0.79x, left); (i) Pan sp. (0.23x, left). From (a) to (f), muscles are pennate and from (g) to (i) are fusiform. ∗ indicates the palmaris longus.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4016873&req=5

fig1: Photos of the forearms of (a) Propithecus sp. (0.45x, left); (b) Lemur catta (0.52x, left); (c) Sapajus libidinosus (0.34x, right); (d) Ateles sp. (0.1x, right); (e) Callithrix sp. (0.3x, right); (f) Aotus sp. (0.8x, right); (g) Macaca fuscata (0.34x, right); (h) Pongo sp. (0.79x, left); (i) Pan sp. (0.23x, left). From (a) to (f), muscles are pennate and from (g) to (i) are fusiform. ∗ indicates the palmaris longus.

Mentions: In all primates studied here, the PL tendon, originated from medial humeral epicondyle and inserted into the palmar fascia, was innervated by the median nerve. A close relationship between the palmaris longus tendon and the fascia of the forearm was observed, which is similar to other flexor muscles of the forearm. The belly of palmaris longus was easily distinguished from the other muscles of the forearm in all studied species, except for the only exemplar of Ateles sp., in which the flexor muscles formed one group of bellies from the elbow with a separation of tendons close to the wrist (Figure 1).


Morphometric and statistical analysis of the palmaris longus muscle in human and non-human primates.

Aversi-Ferreira RA, Bretas RV, Maior RS, Davaasuren M, Paraguassú-Chaves CA, Nishijo H, Aversi-Ferreira TA - Biomed Res Int (2014)

Photos of the forearms of (a) Propithecus sp. (0.45x, left); (b) Lemur catta (0.52x, left); (c) Sapajus libidinosus (0.34x, right); (d) Ateles sp. (0.1x, right); (e) Callithrix sp. (0.3x, right); (f) Aotus sp. (0.8x, right); (g) Macaca fuscata (0.34x, right); (h) Pongo sp. (0.79x, left); (i) Pan sp. (0.23x, left). From (a) to (f), muscles are pennate and from (g) to (i) are fusiform. ∗ indicates the palmaris longus.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4016873&req=5

fig1: Photos of the forearms of (a) Propithecus sp. (0.45x, left); (b) Lemur catta (0.52x, left); (c) Sapajus libidinosus (0.34x, right); (d) Ateles sp. (0.1x, right); (e) Callithrix sp. (0.3x, right); (f) Aotus sp. (0.8x, right); (g) Macaca fuscata (0.34x, right); (h) Pongo sp. (0.79x, left); (i) Pan sp. (0.23x, left). From (a) to (f), muscles are pennate and from (g) to (i) are fusiform. ∗ indicates the palmaris longus.
Mentions: In all primates studied here, the PL tendon, originated from medial humeral epicondyle and inserted into the palmar fascia, was innervated by the median nerve. A close relationship between the palmaris longus tendon and the fascia of the forearm was observed, which is similar to other flexor muscles of the forearm. The belly of palmaris longus was easily distinguished from the other muscles of the forearm in all studied species, except for the only exemplar of Ateles sp., in which the flexor muscles formed one group of bellies from the elbow with a separation of tendons close to the wrist (Figure 1).

Bottom Line: The palmaris longus is considered a phylogenetic degenerate metacarpophalangeal joint flexor muscle in humans, a small vestigial forearm muscle; it is the most variable muscle in humans, showing variation in position, duplication, slips and could be reverted.It is frequently studied in papers about human anatomical variations in cadavers and in vivo, its variation has importance in medical clinic, surgery, radiological analysis, in studies about high-performance athletes, in genetics and anthropologic studies.Hypothetically, the comparison of the relative length of tendons and belly could indicate the pathway of the degeneration of this muscle, that is, the degeneration could be associated to increased tendon length and decreased belly from more primitive primates to those most derivate, that is, great apes to modern humans.

View Article: PubMed Central - PubMed

Affiliation: Department of Anatomy, Howard University College of Medicine, 520 W Street NW, Numa Adams Building, Washington, DC 20059, USA ; Laboratory of Primate Anthropology, Biochemistry, Neurosciences and Behavior, Federal University of Tocantins, NS 15 Avenue, Block 109 Norte, Plano Diretor Norte, 77001-090 Palmas, TO, Brazil ; Graduate School of Animal Biology, Institute of Biology, University of Brasilia, Darcy Ribeiro Campus, 70910-900 Brasília, DF, Brazil ; Department of Physiology, Laboratory of Neuroscience and Behavior, University of Brasilia, Darcy Ribeiro Campus, 70910-900 Brasília, DF, Brazil.

ABSTRACT
The palmaris longus is considered a phylogenetic degenerate metacarpophalangeal joint flexor muscle in humans, a small vestigial forearm muscle; it is the most variable muscle in humans, showing variation in position, duplication, slips and could be reverted. It is frequently studied in papers about human anatomical variations in cadavers and in vivo, its variation has importance in medical clinic, surgery, radiological analysis, in studies about high-performance athletes, in genetics and anthropologic studies. Most studies about palmaris longus in humans are associated to frequency or case studies, but comparative anatomy in primates and comparative morphometry were not found in scientific literature. Comparative anatomy associated to morphometry of palmaris longus could explain the degeneration observed in this muscle in two of three of the great apes. Hypothetically, the comparison of the relative length of tendons and belly could indicate the pathway of the degeneration of this muscle, that is, the degeneration could be associated to increased tendon length and decreased belly from more primitive primates to those most derivate, that is, great apes to modern humans. In conclusion, in primates, the tendon of the palmaris longus increase from Lemuriformes to modern humans, that is, from arboreal to terrestrial primates and the muscle became weaker and tending to be missing.

Show MeSH
Related in: MedlinePlus