Perceived barriers to and facilitators of physical activity in people with knee osteoarthritis: development of the Evaluation of the Perception of Physical Activity questionnaire.

•The level of regular physical activity is low in the knee osteoarthritis population.•Health professionals lack tools to identify the barriers to and facilitators of regular practice of physical activity, particularly for people with knee osteoarthritis.•The Evaluation of the Perception of Physical Activity is a validated and easy-to-use questionnaire for identifying barriers to and facilitators of physical activity.