In the two cycles of T32 support we have had to date, for our Comprehensive Musculoskeletal Training Program, (CMTP) we have successfully trained 15 predoc, 14 postdoc, and 19 summer medical students, for careers in musculoskeletal science. Most of those trainees have gone on to secure their own independent or semi-independent funding, and all have remained in the MSK field in one form or another (faculty, government labs, pharma/industry, or other MSK training opportunities for those who are still junior). We propose in this renewal application to maintain the number of predoctoral trainee positions and short-term medical student positions at four each, but reduce our postdoctoral slots from 4 to 3, to reflect the nationwide postdoctoral fellow shortage affecting most programs. We will continue our highly successful strategy to dedicate of one postdoctoral slot to a one-year research rotation for a resident in orthopaedic surgery, to bolster the orthopaedic physician-scientist footprint in MSK research. Since the last submission, we have devised several new developments that strengthen the training program, making it more multi-disciplinary, and providing greater opportunities for cross talk between basic, translational, and clinical training and research. These include a "flipped" seminar series (trainee driven); a formal, nationally administered mentor training program (to improve mentoring quality); two trainee exchange/internship programs; trainee involvement in the incoming BioEngineering Institute, (launches in late 2024); a "hands-on" grant review training program for postdocs; a wide selection of newly developed and approved MSK-focused courses as part of the new Musculoskeletal PhD program; access to a newly hired, MSK-dedicated informatics/big data integration faculty member; and many new skeletal muscle (and bone) biologists/trainers on faculty. Continued assets for MSK training at IU include the Indiana Center for Musculoskeletal Health (ICMH) (with a full-time Director), the creation of the ICMH MSK Clinical Research Core through an NIH P30 grant award, and the nation's only Musculoskeletal Biology PhD program. The goals of the CMTP are to (1) expand and integrate current musculoskeletal research and teaching programs in the basic, clinical, and engineering sciences; (2) train young scientists at both the predoctoral and postdoctoral levels for research careers as basic scientists, bioengineers, clinical and translational investigators pursuing the causes of, and solutions to, musculoskeletal disease; and (3) train both predoctoral and postdoctoral students/fellows, according to the 6 Core Competencies outlined by the National Postdoctoral Association. Key activities will include the development of a discipline-specific knowledge base, research skill development, and enhancement of communication skills, professionalism, leadership and management skills, and training in the Responsible Conduct of Research. The program includes 30 tra...