“Pollical palmar interosseous muscle” (musculus adductor pollicis accessorius): Attachments, innervation, variations, phylogeny, and implications for human evolution and medicine

Abstract

Most atlases and textbooks dealing with human anatomy do not refer to the "pollical palmar interosseous" (PPI) muscle of Henle. In order to undertake a fresh and detailed study of this muscle and to thus better understand human comparative anatomy and evolution, we: 1) analyze the frequency of the PPI in a large sample of human hands; 2) describe the attachments, innervation and varieties of the PPI in these hands; 3) compare the data obtained with the information available in the literature; and 4) discuss the phylogenetic origin of the PPI and the implications of our observations and comparisons for medicine and for the understanding of human evolutionary history. Within the 72 hands dissected by us, the PPI is present in 67 hands (93%), commonly having a single muscular branch, originating from the medial side of the base of metacarpal I only, inserting onto the medial side of the base of the pollical proximal phalanx and/or surrounding structures (e.g., ulnar sesamoid bone, wing tendon of extensor apparatus), and passing at least partially, and usually mainly, medial to the princeps pollicis artery. A careful study of the human PPI, as well as a detailed comparison with other mammals, strongly suggest that the muscle is evolutionarily derived from the adductor pollicis, and namely from its oblique head. Therefore, we propose that PPI should be designated by the name musculus adductor pollicis accessorius, which indicates that the muscle is most likely a de novo structure derived from the adductor pollicis.

Comparative Anatomy, Evolution, and Homologies of Tetrapod Hindlimb Muscles, Comparison with Forelimb Muscles, and Deconstruction of the Forelimb‐Hindlimb Serial Homology Hypothesis

“… 4A As explained by Diogo et al (), in the human foot the adductor pollicis accessorius (“volaris primus of Henle”: Diogo et al, ; Bello‐Hellegouarch et al, ) is mirrored by the “interosseus plantaris hallucis” sensu Cihak (), which as the “volaris primus of Henle” is probably derived from the contrahentes layer and namely from the adductor hallucis in this specific case, but could alternatively be derived from the flexores breves profundi layer. It should also be noted that both the transverse and oblique heads of the adductor pollicis are mainly derived ontogenetically from the anlage of contrahens 1, while in the foot the oblique head of the adductor hallucis is derived from the anlage of contrahens 1 but the transverse head is derived from a different, neomorphic anlage of the contrahens layer (e.g.…”

Anatomical Network Comparison of Human Upper and Lower, Newborn and Adult, and Normal and Abnormal Limbs, with Notes on Development, Pathology and Limb Serial Homology vs. Homoplasy

“…As our ape ancestors also used the LLs to move on the trees (e.g. grasp tree branches, that is why apes are often called 'quadrumana'), they also had a highly mobile big toe, as extant apes do [ 66 ], and the human LL anatomical network organization revealed by AnNA might reflect that evolutionary history. Therefore, further comparative studies of other primates are needed, for instance to analyze whether there is effectively a similar modular configuration of the big toe in the LL of other primates and particularly apes.…”

“…We have compared the network partition in modules of each limb with functional and developmental null hypotheses. We elaborated detailed tables dividing the structures seen in the normal human ULs and LLs in functional and developmental groups ( S5 Methods ; S6 Methods ), based on previous comparative, evolutionary and developmental work and our review of the literature [ 28 , 50 , 51 , 66 , 70 , 83 , 84 ]. By doing this, we can directly compare, for each system, the overall modular organization of the network with those functional vs .…”

Anatomical variations of the deep head of Cruveilhier of the flexor pollicis brevis and its significance for the evolution of the precision grip

“…Finally, Day and Napier [ 34 ] undertook a systematic dissection of 65 Human hands followed in 1963 by the dissection of 27 different primate genera (41 hands [ 35 ]). Before and during the intervening years several studies on the thumb muscles clearly established the constant incidence of the interosseous palmaris I of Henle [ 36 – 40 ]. Additionally, phylogenetic and ontogenetic investigations have continued to advance our knowledge of the human thumb [ 12 – 14 , 41 – 46 ].…”