Knee osteoarthritis (KOA) is a common condition characterized by chronic joint pain and stiffness, leading to the limitation of daily living activities and physical function. Foot characteristics and mechanics, including static foot posture and dynamic foot function may significantly contribute to musculoskeletal conditions of the lower limb. Therefore the aim of this systematic review was to provide an overview of the foot characteristics and mechanics that have been evaluated in the literature in people with KOA, and investigate whether foot characteristics and mechanics vary between people with and without KOA.
Five electronic databases were searched for studies including the terms ‘foot’ and ‘knee osteoarthritis’. A total of 10,899 studies were retrieved and after review of the literature, 39 articles found to have evaluated foot characteristics and/or mechanics in individuals with KOA.
The 39 included studies included a total of 2260 participants, and of the studies 25 were observational studies and 14 were intervention studies. The majority of studies (64%) were categorised as low study quality using the STROBE checklist.
Two measures, foot progression ankle and peak rearfoot eversion angle were reported in a way allowed for combined analysis of data through meta-analysis. These results indicated no significant difference between people with and without KOA. Foot posture was reported differently in six different studies, making meta-analysis not possible. However, the studies indicated more pronated foot posture in people with KOA compared to people without. As the measurement of foot posture occurred at a single point in time, it is not possible to determine whether foot posture was a cause or effect of KOA. However, the findings highlight the importance of the kinetic chain and biomechanical influence of one joint on another.
There were limitations with the systematic review. Foot measures were only reported in one or two studies with a small sample of participants, which may limit their generalisability to the wider KOA population. Further, it was identified that the quality of the studies were mostly low.
Overall, this systematic review provided a useful snapshot of our current understanding of the link between the foot and KOA.
You can read the full study here.