The 84th Annual Meeting of the American Association of Physical Anthropologists (2015)


Effects of the relative position of the fibula on the cross-sectional geometric properties of the tibia

ALICE E. FAZLOLLAH1, BENJAMIN M. AUERBACH1 and COLIN N. SHAW2.

1Department of Anthropology, University of Tennessee, 2Department of Archaeology and Anthropology, University of Cambridge

March 27, 2015 , Archview Ballroom Add to calendar

Previous studies indicate that the fibula acts as a lateral strut for the ankle and a support for the distribution of forces acting on the shank. The position of the lower limb in the frontal plane and relative mobility of the fibula may influence the strength of the relationship between the tibia and fibula during load sharing among hominoids. In humans, fibular rigidity is increased in athletes versus controls, indicating an increased importance in load sharing with greater activity.

While these studies demonstrate the utility in studying the fibula as a load bearing bone and in assessing load-bearing patterns related to behavior, the geometric relationships that relate to static mechanical properties are unknown. This study is the first to document the spatial relationships of the tibia and fibula and the effects these relationships have on cross-sectional geometric (CSG) properties in a sample of living subjects whose activity patterns are documented (n = 83). Based on prior evidence, tibial strength properties and cross-sectional shape are expected to relate to the relative anteroposterior location of the fibula, and the distance between the centroids of the two bones.

Preliminary results show that fibular location is related to CSG properties of the tibia. Fibular CSG properties relating to strength and rigidity are greater when the centroid of the fibula is more proximal to the centroid of the tibia. Tibiae are stronger in a mediolateral plane when corresponding centroids of fibulae are more posterior. These trends are compared among individuals habitually practicing different activities.