Morphological and evolutionary insights into the keystone element of the human foot’s medial longitudinal arch

Rita Sorrentino, Kristian J. Carlson, Caley M. Orr, Annalisa Pietrobelli, Carla Figus, Shuyuan Li, Michele Conconi, Nicola Sancisi, Claudio Belvedere, Mingjie Zhu, Luca Fiorenza, Jean Jacques Hublin, Tea Jashashvili, Mario Novak, Biren A. Patel, Thomas C. Prang, Scott A. Williams, Jaap P.P. Saers, Jay T. Stock, Timothy RyanMark Myerson, Alberto Leardini, Jeremy DeSilva, Damiano Marchi, Maria Giovanna Belcastro, Stefano Benazzi

Research output: Contribution to journalArticlepeer-review

2 Scopus citations


The evolution of the medial longitudinal arch (MLA) is one of the most impactful adaptations in the hominin foot that emerged with bipedalism. When and how it evolved in the human lineage is still unresolved. Complicating the issue, clinical definitions of flatfoot in living Homo sapiens have not reached a consensus. Here we digitally investigate the navicular morphology of H. sapiens (living, archaeological, and fossil), great apes, and fossil hominins and its correlation with the MLA. A distinctive navicular shape characterises living H. sapiens with adult acquired flexible flatfoot, while the congenital flexible flatfoot exhibits a ‘normal’ navicular shape. All H. sapiens groups differentiate from great apes independently from variations in the MLA, likely because of bipedalism. Most australopith, H. naledi, and H. floresiensis navicular shapes are closer to those of great apes, which is inconsistent with a human-like MLA and instead might suggest a certain degree of arboreality. Navicular shape of OH 8 and fossil H. sapiens falls within the normal living H. sapiens spectrum of variation of the MLA (including congenital flexible flatfoot and individuals with a well-developed MLA). At the same time, H. neanderthalensis seem to be characterised by a different expression of the MLA.

Original languageEnglish (US)
Article number1061
JournalCommunications Biology
Issue number1
StatePublished - Dec 2023

All Science Journal Classification (ASJC) codes

  • Medicine (miscellaneous)
  • General Biochemistry, Genetics and Molecular Biology
  • General Agricultural and Biological Sciences

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