Personalized training and orthopedic inserts bring significant benefits in the posturographic assessment of patients with early gonarthrosis – a randomized controlled trial

Knee osteoarthritis (KOA) results from cartilage degeneration and abnormal load distribution, leading to impaired biomechanics and postural control. Foot abnormalities such as hypermobility, flat feet, and pronation-common in KOA-may contribute to the degeneration process of the knee joint structures. Stabilization and proprioceptive exercises, as well as orthopedic inserts, can modify these factors by improving muscle function and redistributing load. However, studies directly comparing their effectiveness using objective assessment methods are lacking. Postural control plays a key role in KOA because it reflects the integration of balance systems. The aim of the study was to evaluate the effect of these interventions and their combination on postural balance in centre of pressure (COP) and clinical outcomes (KOOS - knee injury and osteoarthritis outcome score) in patients with early KOA. Participants were randomly divided into four groups: "Exercises" (n = 43), "Orthopaedic insoles" (n = 43), "Mixed" (n = 39), "Control" (n = 41). During the qualification process, a posturographic examination was performed on a force platform with eyes open and closed in a standing position. Participants were also assessed using the KOOS questionnaire. The obtained data were analyzed in Statistica 13 using the Wilcoxon signed-rank test and the Kruskal-Wallis ANOVA test. A significance level of p = 0.05 was used. Posturographic parameters such as sways length and mean speed with eyes open and closed improved, and the ellipse area of the center of gravity decreased in the mixed group (p = 0.001). The largest clinical effects were observed for sways length with eyes open (d = 2.512) between the control and exercise groups and for sways length with eyes closed (d = 2.172), ellipse area with eyes open (d = 1.361), and mean speed with eyes closed (d = 2.193) between the control and mixed groups. Quality of life (QoL) and functioning improved statistically, and significant between-group differences were found for pain, symptoms, physical activities of daily living (ADL), sports/recreation, and QoL (p < 0.001). However, there were no significant differences between the exercise group and the orthopedic insole group in terms of symptoms, ADL, sports/recreation, and QoL. A significant clinical effect was observed on the KOOS pain score between the insoles and exercise groups (d = 1.122). The combined use of orthopedic insoles and exercises is the most effective method of rehabilitation.Trial registration: The study was registered in the international Research Registry database (https://www.researchregistry.com/) under registration number researchregistry11661.