The candidate for this Mentored Research Scientist Development Award, Sharon M. Henry, Ph.D. PT, is a physical therapist. Her clinical work covers the rehabilitation of persons with neurological and musculoskeletal impairments particularly low back pain (LBP). She has assisted with several clinical studies of LBP patients conducted through the Rehabilitation Engineering Center (REC) for LBP at the University of Vermont (UVM). Being interested in the role of somatosensory information in motor control, Dr. Henry proceeded to earn her Ph.D. in the Anatomy and Neurobiology Department at UVM, and completed her post- doctoral fellowship with Dr. Fay Horak in Portland OR. During this time, Dr. Henry received three post-doctoral awards and completed studies examining postural responses in healthy and spinal cord injured subjects. Her long term goals include examining motor control issues in patients with musculoskeletal impairments, specifically LBP. As a researcher and clinician, Dr. Henry wishes to contribute to the field of medical to the field of medical rehabilitation and conduct research that will impact on the way physical therapists and other rehabilitation specialists treat patients. Dr. Henry has a position as assistant professor in the Physical Therapy Department at UVM. The Department has committed to starting a new 2100 square foot state-of-the-art Motion Analysis Laboratory and has committed to fostering Dr. Henry's career as an independent investigator. Within the Department, there are several other faculty members who are involved in motor control and LBP research. In addition, there is an active scientific community on campus through the REC that has been conducting LBP research since 1982. The studies proposed in this application reflect a merging of Dr. Henry's background and interests. It has long been thought that poor neuromuscular control of trunk muscles may lead to injury by causing local mechanical damage to spinal structures, and thus, LBP. However, little is known about the function of specific trunk muscles in normal subjects during various activities of daily living (Specific aim 1), and the precise muscle dysfunction associated with LBP has not been satisfactorily characterized (Specific aim 2). Therefore, a better understanding is needed of when trunk muscles in active spinal and postural stabilization in healthy and in selected groups of persons with LBP. This goal will be achieved by characterizing muscle, kinematic, and force strategies used to control truck/spine in postural responses to multi-directional, multi-velocity surface translations. By having a better understanding of trunk motor coordination, evaluation and treatment strategies can be more specific and more effective in the rehabilitation of persons with LBP.