title: Challenges.
authors.forename: Kim
authors.initials: K
authors.lastname: Burton
authors.forename: Paul
authors.initials: P
authors.lastname: Brinckmann
mesh_terms: D005080:Exercise Test / Q000379:methods*; D005684:Gait; D020233:Gait Disorders, Neurologic / Q000175:diagnosis* / Q000503:physiopathology*; D006801:Humans; D010003:Osteoarthritis / Q000175:diagnosis* / Q000503:physiopathology*; D005082:Physical Exertion