Muscle Fatigability and Trip-specific Fall Risk in Adults With Knee Osteoarthritis

Inclusion Criteria: For adults with knee osteoarthritis: * presence of occasional to frequent knee pain * knee pain that is primarily in the medial knee joint compartment * minimal morning joint stiffness For all participants: * able to walk continuously for 30 minutes without an assistive device Exclusion Criteria: * fracture or surgery within 1 year * history of joint replacement * lower-extremity joint injections within 3 months * history of stroke or other neurological condition * cardiovascular or pulmonary conditions that limit daily activity or that preclude participation in exercise * history of major lower extremity or back injury or pain (except for knee osteoarthritis) * history of lower extremity amputation * use an orthotic or prosthetic to walk * use of beta blockers or other medications that affect fatigue * use of medications that affect balance * diabetic neuropathy * acute illness or the presence of lesions on the torso or lower extremities * BMI greater than 35 * body weight over 265 lbs