Baby steps towards linking calcaneal trabecular bone ontogeny and the development of bipedal human gait

Abstract

Trabecular bone structure in adulthood is a product of a process of modelling during ontogeny and remodelling throughout life. Insight into ontogeny is essential to understand the functional significance of trabecular bone structural variation observed in adults. The complex shape and loading of the human calcaneus provides a natural experiment to test the relationship between trabecular morphology and locomotor development. We investigated the relationship between calcaneal trabecular bone structure and predicted changes in loading related to development of gait and body size in growing children. We sampled three main trabecular regions of the calcanei using micro‐computed tomography scans of 35 individuals aged between neonate to adult from the Norris Farms #36 site (1300 AD, USA) and from Cambridge (1200–1500 AD, UK). Trabecular properties were calculated in volumes of interest placed beneath the calcaneocuboid joint, plantar ligaments, and posterior talar facet. At birth, thin trabecular struts are arranged in a dense and relatively isotropic structure. Bone volume fraction strongly decreases in the first year of life, whereas anisotropy and mean trabecular thickness increase. Dorsal compressive trabecular bands appear around the onset of bipedal walking, although plantar tensile bands develop prior to predicted propulsive toe‐off. Bone volume fraction and anisotropy increase until the age of 8, when gait has largely matured. Connectivity density gradually reduces, whereas trabeculae gradually thicken from birth until adulthood. This study demonstrates that three different regions of the calcaneus develop into distinct adult morphologies through varying developmental trajectories. These results are similar to previous reports of ontogeny in human long bones and are suggestive of a relationship between the mechanical environment and trabecular bone architecture in the human calcaneus during growth. However, controlled experiments combined with more detailed biomechanical models of gait maturation are necessary to establish skeletal markers linking growth to loading. This has the potential to be a novel source of information for understanding loading levels, activity patterns, and perhaps life history in the fossil record.

Biomechanical Analysis of a Novel Double-Point Fixation Method for Displaced Intra-Articular Calcaneal Fractures

“…The principal compressive trabeculae play a major role in resisting the stresses contributed by muscle forces and body weight. It sits on the posterior half of the calcaneus and extends from the posterior facet joint toward the calcaneal tuberosity ( Saers et al, 2020 ), which is the point of fixation in DPF. Inserting the DPF along with the trabecular orientation could maintain the alignment and structure of the principal compressive trabeculae and, thus, could facilitate fracture union and functional recovery.…”

Combinations of trabecular and cortical bone properties distinguish various loading modalities between athletes and controls

“…The low resolution pQCT scanning used to assess trabecular BMD cannot quantify aspects of trabecular microstructure such as the degree of anisotropy and primary direction of material stiffness, which are known to correspond to joint specific loading conditions (Barak et al, 2011; Saers et al, 2016; Saers, Ryan, & Stock, 2019b; Tsegai, Skinner, Pahr, Hublin, & Kivell, 2018). As such, BMD does not reflect the full potential of functional adaptation of trabecular bone to loading conditions associated with different types of sports.…”

Assessing biases in the analysis of trabecular bone microarchitecture of non-adult individuals

“…Also, we suggest that intra-individual variability can be interpreted by comparing a series of VOIs between themselves. In studies interested in developmental processes, multiplication of VOIs permits detection of structural organisation heterogeneity and growth dynamics (Colombo, 2014;Saers et al, 2020).…”

“…We consider as important to be mentioned, because trabecular bone analysis during development is quite rare (e.g. Colombo et al, 2019;Ryan and Krovitz, 2006;Ryan et al, 2017;Saers et al, 2020) in both biomedical (e.g., mainly studied for senescence and fracture healing) and anthropological literature.…”