Climbing stairs is an important activity of daily living. For patients with muscle weakness or arthritis, ascending and descending stairs can be very difficult, if not impossible. Being able to negotiate stairs could dramatically improve the quality of life of these individuals with physical impairments. In the HPB Lab, we are currently investigating how different surgical techniques and joint replacements effect how patients negotiate a simple set of stairs. We are also interested in how volunteers with knee arthritis climb stairs with the help of an assistive walking device.