While it is recognized that bone health is influenced by physical activity, it remains unclear whether it is the intensity, duration, or frequency of activity that has the most positive impact on skeletal integrity. This research investigates how the skeleton of primates (such as humans) adapts to physical activity through examination of the differential impact of diverse forms of locomotor behavior on multiple measures of bone anatomy. The integrated approach requires a study population for which the requisite behavioral, biomechanical, and bone structure data are accessible; the bone samples examined therefore come from a population of seven African primate species for which locomotor behavior and activity patterns have been under study for over 15 years, providing a unique and broad spectrum of behavioral variation from which to investigate how bones respond to different activity regimens. Through examination of these interrelationships, the research will improve understanding of the influence of physiological activity (e.g., intensity and frequency of running) on bone structure and adaptation, and thereby identify the types of activity that influence the integrity of limb bones.
The study combines consideration of bone quantity (size) with quality (stiffness) to calculate measures of bone structural integrity. Bone quality is determined through the technique of microindentation, a method that measures small-scale variation in bone stiffness throughout bones to permit detailed understanding of bone strength, including fracture risk. In addition, how different types of locomotor activity (walking, running, jumping) and activity levels (amount of time spent per day in locomotion) influence bone adaptation is assessed through the different perspectives of kinetics (the measurement of forces on the skeleton) and remodeling (the process by which bone repairs itself). Through this comparative and multifaceted approach, this research seeks to establish what aspects of physical activity are influential in either positively or negatively affecting bone strength.
The overarching intellectual merit of this study is that in determining the association between bone anatomy and locomotor behavior, the kinds of activity that can positively influence bone adaptation may be identified. Such results should find application to clinical contexts for human populations in establishing more definitive links between behavior and anatomy, and through refined assessments of bone quality that can be used as an index of bone health and function. In addition, several impacts of societal importance emerge from this research activity. These include interdisciplinary training in anthropology, engineering, and the health sciences for both undergraduate and graduate US students; inclusion of underrepresented groups in engineering and anthropological research; contributions to the conservation of threatened primate populations; and improvement of educational infrastructure at the university level across three US institutions.
