The ultimate goal of this research is to reduce the risk and prevalence of upper extremity work related musculoskeletal disorders (WMSDs) among residential construction workers. The prevalence and cost of WMSDs in construction illustrate the need for effective interventions to control and prevent their development. Research has indicated significant inter-individual variation of work strategies. These differences may explain why some workers are more susceptible to injury that others. Further, as WMSDs develop over prolonged periods of time, increased exposures to risk factors for WMSDs early in a persons work life due to inexperience or inefficient work strategies may increase risk for injury development. Engineering controls can have only a limited role in construction as this work is mainly manual and fundamental changes are unlikely in the foreseeable future. It can be hypothesized that survival in construction tasks is due, at least, in part to these `experts' having identified efficient work strategies that reduce exposures to risk factors and injury risk. It is hence assumed in this proposal that expert work practices differ from novices and are directly observable and/or measurable. Carpenters have been selected for evaluation based on injury rates and to scope the research a laboratory study has been developed to quantify differences between expert and novice participants during simulation of actual construction tasks. ? ? There are two objectives to this research: (1) characterize and contrast work strategies of expert and novice residential construction workers using laboratory-based simulation, (2) assess ergonomic risks associated with these differing strategies. The longer term goal would be assess the efficacy of using expert strategies for training methods to reduce incidence rates. Successful completion of this work will provide important information on individual differences in performance methods, and toward long- term control of work related injuries among residential construction workers. ? ? ?