The objective of this study was to objectively measure daily physical activity and spatiotemporal gait pattern, as well as improvements in self reported symptoms and quality of life, before and six weeks after an intra-articular corticosteroids injection in patients suffering from knee osteoarthritis. Fourteen patients with unilateral knee osteoarthritis were recruited. The intra-articular corticosteroid injection was given at the end of the second week. Physical activity was objectively measured by an accelerometer worn by the participants for eight weeks. In addition, the Western Ontario and McMaster Universities Arthritis Index (WOMAC), the Medical Outcome Study Short Form-36 (MOS-SF36) and gait trials were completed every two weeks to assess symptoms, quality of life and spatiotemporal parameters of gait.