Dr. Marshall has a strong focus on epidemiologic and statistical methods that can be applied to research on many different types of health outcomes.  Her research is collaborative, involving not only epidemiologic methods and statistical analysis, but also disciplines that guide investigation of biologic mechanisms and clinical relevance.  With her colleagues in the Department of Orthopaedics and Rehabilitation, she studies spine conditions associated with low back pain and outcomes of knee injury.  With colleagues in the Department of Biochemistry and Molecular Biology, she is studying the role of age-related connective tissue breakdown in loss of muscle mass.  Finally, as an investigator with the multidisciplinary MrOS Research group, she studies conditions of aging in older men, including lower urinary tract symptoms, bone metabolism, loss of muscle mass and strength, and fracture.