Musculoskeletal Biomechanics research focuses on bone tissue and orthopaedic biomechanics. Interests include bone and skeletal mechanical loading states, mechanosensory systems, fluid flow, imaging and microarchitecture.
The following laboratories are within our Musculoskeletal Biomechanics focus area:
Multiscale Biomechanics and Functional Imaging Laboratory
Principal Investigator: Dr. Luis Cardoso
The Multiscale Biomechanics and Functional Imaging Laboratory aims to integrate biomechanics, bioinstrumentation, signal and image processing to develop theories, analytical models and diagnosis tools for diseases like arthritis, osteoporosis and atherosclerosis. Their theories explain different events of osteo-articular and cardiovascular disorders. Analytical and experimental multi-scale numerical models determine the biomechanical, functional relationship of such connective and cardiovasular tissues before and after onset of degeneration. The group has developed and applied several techniques to characterize the macro and microarchitecture of such tissues using micro CT. Related mechanical behavior of the tissue is analyzed using ultrasound and finite element modeling, in animal and human specimens. Bone research focuses on the characterization of cancellous bone microarchitecture using ultrasound, with an emphasis on the anisotropy of the bone structure. For osteo-articular tissues, the research focus is to develop micro-CT protocols to visualize the macroscopic morphology of cartilage using x-ray opaque agents. The cardiovascular research area focuses on analysis of the rupture of thin caps of atherosclerotic blood vessels due to cellular level micro-calcifications.
Tissue Mechanics Laboratory
Principal Investigator: Dr. Susannah Fritton
The focus of the Tissue Mechanics Laboratory is to understand the adaptive response of bone to altered physiological conditions. The lab uses a combined experimental and computational approach to investigate interstitial fluid flow around osteocytes, which is believed to play a role in the mechanism by which bone tissue detects external mechanical stimuli and deposits or resorbs bone, as needed. A major thrust of the current research effort is to understand how bone mechanotransduction is altered in postmenopausal and disuse osteoporosis. An ongoing project in collaboration with investigators at the Hospital for Special Surgery involves relating bone microstructure and cellular-level changes to alterations of interstitial fluid flow in osteoporotic bone. Another current project investigates whether reduced mechanical loading causes changes in the bone microporosities and osteocyte environment that diminish bone’s ability to detect mechanical loading. Techniques developed in the lab are also being applied to the field of cancer drug delivery in a project with collaborators at Memorial Sloan-Kettering Cancer Center that investigates the efficacy of applying mechanical loading to enhance delivery of therapeutic agents to bone tumors.
Bone and Joint Laboratory
Principal Investigator: Dr. Mitchell B. Schaffler
The Bone and Joint Laboratory’s major research emphasis is to understand the developmental, maintenance and repair mechanisms of skeletal tissues (bone, ligament, tendon, cartilage), which allow them to meet mechanical demands and changes through life. The laboratory focuses 1) on the local cellular and integrative processes that control the architectural features of bone and tendon and govern their normal responses to physical challenges in aging and disease states such as osteoporosis, genetic defects and diabetes, and 2) the mechanical failures that result when skeletal biological systems cannot maintain tissue material properties. Current research efforts focus on fatigue damage and repair in bone and tendon, with specific emphasis on how living cells in these tissue detect and repair wear and tear damage before it accumulates to the point of mechanical failure. Additionally, the influence of osteocytes on bone mechanical function is analyzed both directly by modulating local matrix composition, and indirectly by controlling local bone remodeling activities. In related studies, osteocyte function as a mechanical sensor allowing bone to perceive and react to mechanical loading is being examined. Experimental approaches include in vivo and tissue mechanical loading, microscopy, micro CT, and molecular biology.
Dr. Stephen Cowin studies the mechanics of materials, particularly in the determination of the influence of microstructure on the gross mechanical behavior of granular, composite, and biological materials. He is known for his analysis of static bin pressure induced by granular materials, his development of a continuum theory for granular materials, the creation of the continuum theory of materials with small voids, the development of models of granular material slip zones, basic theorems in anisotropic elasticity and the development of bone remodeling theories and computational algorithms.
Dr. Sheldon Weinbaum has worked with Dr. Cowin on developing a theoretical framework for fluid flow induced excitation of osteocytes in bone. In 1994 they published a landmark paper on fluid shear stimulation of osteocyte cell processes and in 2001, working also with Dr. Schaffler, they introduced a new hypothesis for strain amplification in the actin cytoskeleton of cell processes due to fluid drag on the tethering elements in the pericellular matrix. Drs. Cowin, Fritton and Weinbaum initiated the first International Bone Fluid Flow Workshop in 1997 and have organized three of the meetings.