Rick Lieber earned his Ph.D. in Biophysics from U.C. Davis developing a theory of light diffraction that was applied to mechanical studies of single muscle cells. He joined the faculty at the University of California, San Diego in 1985 where he spent the first 30 years of his academic career, achieving the rank of Professor and Vice-Chair of the Department of Orthopaedic Surgery. He received his M.B.A. in 2013 and is currently Chief Scientific Officer and Senior Vice President at the Rehabilitation Institute of Chicago.
Dr. Lieber’s work is characterized by its interdisciplinary nature—an approach that is relevant to those who study biomechanics and Orthopaedic Surgery. He has published over 250 articles in journals ranging from the very basic such as The Biophysical Journal and The Journal of Cell Biology to those more applied such as The Journal of Hand Surgery and Clinical Orthopaedics and Related Research. Dr. Lieber’s research focuses on design and plasticity of skeletal muscle. Currently, he is developing state-of-the-art approaches to understanding muscle contractures that result from cerebral palsy, stroke and spinal cord injury.
In recognition of the clinical impact of his basic science studies, Dr. Lieber has been honored by the American Academy of Orthopaedic Surgeons (Kappa Delta Award; twice), the American Bone and Joint Surgeons (Nicolas Andry Award) the American College of Sports Medicine (Fellow), and the Council for the International Exchange of Scholars (Fulbright Fellowship) and the American Society for Biomechanics (Borelli Award). He was also recently awarded the Senior Research Career Scientist from the Department of Veterans Affairs.
Optical Studies of Skeletal Muscle in Surgery and Disease
Richard L. Lieber, Ph.D.
Professor and Chief Scientific Officer
Rehabilitation Institute of Chicago
Department of Physical Medicine and Rehabilitation, Northwestern University
Chicago, IL 60611
Skeletal muscle has an impressively regular structure—almost crystalline. It is for this reason that muscle represents the classic biological example of a structure-function relationship. Its structure is intimately tied to its function. The molecular “machine” that powers muscle contraction is known as the sarcomere and this structure is composed of interdigitating protein filaments. The resulting structure has a periodic refractive index variation that makes muscle cells excellent diffraction gratings. We have exploited this property, creating surgical laser tools that measure sarcomere length precisely during surgery of hand, back and knee muscles. Sarcomere length is a critical parameter that quantitatively predicts muscle function. Thus, by measuring sarcomere length, we have uncovered several fascinating design features of human muscles and we have also created a tool that surgeons can use to optimize surgical transfer of muscles. This is important during surgical treatment of patients with stroke, head injuries, cerebral palsy, spinal cord injury and traumatic injury.
We have combined these intraoperative studies with biomechanical studies of isolated single muscle cells that reveal an increased passive modulus and decreased resting sarcomere length suggesting alterations in the cellular cytoskeletal proteins. Similar studies on small bundles of muscle fiber reveal an increase in the compliance of the extracellular matrix and a proliferation of endomysial connective tissue. To resolve these finer subcellular components, we have recently created optical frequency combs (OFC) to illuminate muscle across a range of wavelengths using fiber optics, which makes our device usable in the outpatient setting. We have achieved near-record signal-to-noise ratios based on the use of OFCs and sophisticated data processing. We are excited that this technology may revolutionize muscle measurements in injury and disease and may provide insights into nerve function as well.