Impact of Crutch Type on Gait and Functional Outcomes Post-knee Surgery

Inclusion Criteria: * Subjects 45-75 years old planning to get their first total knee replacement * Subjects 18-45 years old planning to get their first anterior cruciate ligament reconstruction Exclusion Criteria: * Previous injury to shoulder, elbow, or wrist * Current pain in shoulder, elbow, or wrist * Inflammatory arthritis (i.e. rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis), * History of cerebral palsy, stroke, significant cognitive impairment, or significant visual impairment * Problems with the heart or lungs * Currently using a crutch or crutches, walker, or other gait aid * History of using a crutch or crutches for 4 or more weeks * Inability to communicate in English * Current smoker * Currently pregnant