In Vivo 3D Analysis of Thoracic Kinematics: Changes in Size and Shape During Breathing and Their Implications for Respiratory Function in Recent Humans and Fossil Hominins

The human ribcage expands and contracts during respiration as a result of the interaction between the morphology of the ribs, the costo-vertebral articulations and respiratory muscles. Variations in these factors are said to produce differences in the kinematics of the upper thorax and the lower thorax, but the extent and nature of any such differences and their functional implications have not yet been quantified. Applying geometric morphometrics we measured 402 three-dimensional (3D) landmarks and semilandmarks of 3D models built from computed tomographic scans of thoraces of 20 healthy adult subjects in maximal forced inspiration (FI) and expiration (FE). We addressed the hypothesis that…