1. Eduardo Saldías Vergara Assumpció Malgosa Morera Albert Isidro Llorens
Implications of Cuboid facet of Navicular bone in biomechanics of the Midtarsal foot in contemporary Spanish collections. Preliminary results.
Eduardo Saldías Vergara
Assumpció Malgosa Morera
Albert Isidro Llorens

2. As a result of full bipedalism, modern humans changed an opposable hallux to a hallux resistant to charge and gait.
Navicular: Some of the its most recognizable changes were the reduction of its tuberosity and the presence of a clear cuboid facet.
The cuboid facet of the navicular bone is not present in whole the modern individuals but do not exist a clear register between populations.

3. Prang (2016) “Reevaluating the functional implications of Australopitecus afarensis navicular morphology”. Journal of Human Evolution. 97,

6. Antecedents

7. Objectives
To study a contemporary Spanish collection (known sex and age) to check the development of this surface.
To formulate a hypothesis about its existence
To measure a series of navicular dimensions to check a relationship between them and the presence of the cuboid facet.

8. Maximum width of navicular (WMAX)
Maximum height of navicular (HMAX)
Maximum length of the talar facet (LMAXTAL)
Sagital length of the talar facet (LSAGTAL)
Maximum length of the cuneiform surface (LMAXCUN)
Maximum sagital length of the second cuneiform facet (LSAGCUN)
Width of the navicular tuberosity (WTUBER)
Sagital length of navicular (LSAGNAV)
Saldías, Malgosa, Jordana & Isidro (2016) “Sex estimation from the navicular bone in spanish contemporary collections”. Forensic Science International e1-229e6.

9. Materials and methods
Individuals
Age
Male
Female
Total
Mean
Min
Max
S.D
UCM 63 62
125
65.2 20 94
17,1
UAB 41 31 72
74.6 32 97
12.3
UGr 39 70
69.0 22 90
12,5
135
132
267
The human remains were obtained from the UAB collection; Facultad de Medicina collection from Universidad Complutense de Madrid, and Universidad de Granada collection.
Error inter-intra: Relative TEM

10. Results
No intra-inter error to determinate to cuboid facet (morphology).
Low rate of error (RTEM <1,3%) in the intra-observer analysis and acceptable error (<3,7%) in the inter-observer analysis (morphometry).
Majority of individuals developed cuboid facet (52,5% vs 47,8%).
Cuboid facet is more frequent in women.

11. Frequency of cuboid facet

12. Frequency of cuboid facet by population

13. Results
Mann-Whitney U test. Measurements grouped under “Surface” variable, divided by sex.
Sex
WMAX
HMAX
LMAXTAL
LMAXCUN
LSAGCUN
WTUBER
LSAGNAV
LSAGTAL 1
Mann-Whitney U
1329,000
1283,000
1331,500
1115,000
1382,000
1189,500
Wilcoxon test
2410,000
3236,000
2321,500
3058,500
2900,000
2945,000 Z
-, 182
-,901
-,211
-1,149
-,955
-1,703
-,467
-,959
Sig. Asint. (bilateral)
,856
,368
,833
,251
,340
,089
,641
,338 2
1163,500
1363,000
1286,000
1225,000
1311,500
1467,000
1009,500
3116,500
3443,000
3497,000
3784,000
3370,000
2257,500
2457,000
1955,500
-,321
-,290
-,846
-,355
-,510
-,281
-,311
-2,595
,748
,771
,398
,723
,610
,779
,756
,009

14. Discussion
To understand the cuboid facet function in humans is neccesary to review the other primates anatomy.
Chopart joint developed a “locking” during the push-off.
How mobile is our midfoot?
D. Gebo, “Musculo skeletal system,” in Primate comparative anatomy, 1st ed., Baltimore: John Hopkins University Press, 2014, pp. 57–59.

15. Discussion
No one variable is relate with the presence of cuboid facet. It is not depend of navicular form.
The frequency of cuboid facet is similar with that of Pfitzner but different with Gruber, Manners-Smith and Gomberg.
Sociocultural factors, type of ground etc, can have influence in the final results.
New approach in the study: Cinematoradiography in the gait and measurements in the cuboid and talus.

16. previously reviewed through to TAC
Cinematoradiology
10 patients from Sagrat Cor Hospital from Barcelona, with and without cuboid facet
previously reviewed through to TAC

17. Conclusions
52,5% of the contemporary Spanish population collections utilized in this analysis demonstrated cuboid facet.
Cuboid facet frequency: Women > Men
Cuboid facet is not related with the form of the navicular.
New approaches to check the presence.
Cuboid facet is important in other primates to carry out supination movements. In humans, its absence is related with tendency to pronation and its develop is probably linked with a constant but mild supination movement in the feet.

18. Acknowledgements
We would like to thank to: For the access of documented collections of Madrid, Barcelona and Granada: José Antonio Sanchez (UCM) Alfonso Rodriguez (UAB) Miguel Botella and Inmaculada Alemán (UGr) For the financial support: CONICYT PAI/ (ES) (Gobierno de Chile) For their academic support: Dominika Nociarová (UAB) Manuela Uras (Universitá de Sassari of Italy)

19. THANKS