 Knee osteoarthritis OA accounts for a significant proportion of mobility limitations and is one of the most disabling problems facing the growing population of older adults. The long-term objective of this research is to reduce disablement of older adults with symptomatic knee OA. The principle of specificity of training indicates that exercises that closely approximate the goal functional activity are most effective in improving physical performance during that activity. Based on this principle, the specific aim of this pilot study is to design a patient-specific gait training intervention using analysis of compensatory joint moments and energy expenditure. Successful completion will inform rehabilitation for maintaining or improving mobility as well as explore the mechanism of effect. 