Project Summary/Abstract More than 1.6 million persons in the United States are living with the loss of at least one limb.[1] This number is projected to more than double by the year of 2050 due to the aging population. While recent developments in technology have led to sophisticated prostheses, the science underlying learning of prosthetic skills and recovery of mobility after limb loss is not well understood, resulting in large variations in amputee patient care.[2] Specifically, the principles and evidence of motor learning are not available to guide the process of prosthetic skill training in this population.[3, 4] Recovery of mobility after lower limb loss remains a major challenge especially for amputees who are older and with sensorimotor impairments from chronic diabetes.[5-7] In the last 20 years, mounting evidence demonstrated that direction of attentional focus during execution of motor tasks affects effectiveness of motor learning.[8] Specifically, directing one?s attention externally to the movement outcome has been consistently shown to promote learning, when compared to an internal focus on the body movements.[8-10] Manipulation of attentional focus has obvious implications in the clinical context of learning prosthetic skills. If prosthetic motor skill learning can be improved through practice with an external focus of attention, there would be a dramatic transformation in how patients with limb loss are rehabilitated. This K01 Career Development Award will serve to develop my abilities as an independent researcher in the field of motor learning as pertaining to amputee rehabilitation. My goals for this plan are to: 1) advance my knowledge in motor learning science, and 2) obtain training in conducting clinical research in populations with and at risk of limb loss. This plan is a logical extension of my background in clinical biomechanics and my passion for translational research pertaining to amputee rehabilitation. The research projects I propose here will advance our understanding of fundamental principles of motor skill acquisition in individuals with and at risk of limb loss. This will lead to future development of evidence-based amputee rehabilitation strategies. My home institution, the University of Nevada, Las Vegas (UNLV), is committed to advancing collaborative research and educational activities in the health sciences. UNLV Department of Physical Therapy is currently the meeting site for the Southern Nevada group of Amputee Coalition, with which I have active involvement. Key UNLV faculty members who will serve on my Mentoring Committee include Robert Gregor (Professor Emeritus, Georgia Institute of Technology; Research Consultant, UNLV School of Allied Health Sciences) and Gabriele Wulf (Professor, UNLV Department of Kinesiology and Nutrition Sciences). Mentors external to UNLV include Carolee Winstein (Professor, University of Southern California) and Robert Gailey (Professor, University of Miami). Furthermore, the Medical Director of the Amputee Care Clinic in the Department of Rehabilitation at the VA Southern Nevada Healthcare System, Dr. Eric Aguila, has agreed to assist this career development and research plan by providing access to his patient population for the proposed research studies. 3