We hypothesize that individuals exercising with the device will achieve better outcomes in pain, stiffness, strength, and functional measures than a control group or a group exercising according to printed material from arthritis advocacy groups. We will randomly assign study participants meeting eligibility criteria to the exercise device group, exercise according to printed material group, or control group. We will conduct measures in all groups during a clinic visit at baseline, 2, 4, 6, and 8 weeks. As subjects in the exercise device group strengthen their leg muscles, a physical therapist will likely need to adjust upward the target force for different leg positions during every clinic visit, 2 weeks apart.