The purpose of this investigation is to determine the impact of prosthetic device use on self-assessed functional limitations, disability and return to work status among individuals undergoing amputation for severe lower extremity trauma. The findings of this study will help prosthetists and other health and rehabilitation professionals to identify types of prosthetic users who may be at risk for poor outcomes and who might benefit from increased training and rehabilitation. Additional objectives include: (1) identify a typology of prosthetic users according to: a) number of hours device used per day; b) number of days deice used per week, c) how often device used inside home; d) how often deice used outside home; e) functional activities able to do with prothesis on; f) what other assistive devices used in conjunction or instead of prosthetic device; (2) assessing the impact of prosthetic device used on self-assessed functional limitations, disability and turn to work status; and (3) identifying characteristics of patients and their environment that mediate the quality of functional outcomes and return to work status. The data for this study come from the Lower Extremity Assessment Project (LEAP), a multi-center, prospective study of 607 patients with high energy lower extremity trauma or HELET. Those patients eligible for the LEAP study and who agreed to participate are being followed prospectively at 3, 6, 12 and 24 months post surgery. At each follow-up assessment patients undergo: (1) an evaluation by the orthopedist to determine the occurrence of complications, status of the involved limb(s) and subjective assessment of cosmetic appearance, clinical recovery and functional recovery; (2) an evaluation by a physical therapist to determine the level of physical impairment, functional limitation and need for rehabilitation services; and (3) an interview to measure of services and perceived need for additional services. In addition to the sources of data listed above, patients undergoing amputation were also asked a series of questions regarding the use of an satisfaction with their prosthetic device(s). These patients also asked permission to contact their prosthetist and extensive information about the type and cost of the device obtained. Data for the study proposed in the NRSA application includes only LEAP patients undergoing amputation by 12 month follow-up and will be obtained from baseline and 12 month patient and prosthetist questionnaires.