Biomechanical characteristics of stair ambulation in patients with knee OA: A systematic review with meta-analysis toward a better definition of clinical hallmarks

Background: Stair climbing was suggested to be the first affected task in individuals with knee osteoarthritis (OA). Research question: This review aimed to identify consistent kinematic, kinetic, and spatiotemporal alterations of stair climbing exhibited by individuals with knee OA. Methods: A literature search published until September 2017 was conducted in PubMed, PEDro, CINAHL, and Cochrane CENTRAL. Reviewer extracted data in accordance with the Cochrane Handbook. Where possible, data were combined into a meta-analysis; the pooled standardized mean differences between individuals with knee OA and healthy adults were calculated using the random-effect model. Results: In total, 585 potentially relevant articles were selected, of which 12 (695 participants, mean age: 58.4 years) met the inclusion criteria. Meta-analysis revealed that kinematic and kinetic alterations during stair climbing associated with knee OA were lower external knee flexion moment in conjunction with a larger trunk/hip flexion angles and smaller knee flexion/ankle dorsiflexion angles. Individuals with knee OA showed a delayed quadriceps activation during stair ascent. A lack of evidence was detected for alterations in external knee adduction moment during stair climbing. Effect estimate in each meta-analysis was judged "very low" on the GRADE approach. Significance: No strong conclusion can be drawn because of the low quality of evidence; however, individuals with knee OA may exhibit altered kinematics and kinetics changes in sagittal plane during stair climbing, and have delayed quadriceps muscle activity. Further studies with adequate adjustment for confounders are warranted to facilitate clinical hallmarks of the knee OA, particularly in early stages of the disease.