Static Plantar Pressure Distribution and Position Correlations in Early and Mid-term Knee Osteoarthritis Patients

Background: Knee osteoarthritis (KOA) is the most common degenerative joint disease, and patients will develop abnormalities in the movement model. Plantar pressure distribution and body postural characteristics may differ in patients with KOA compared to healthy adults and may affect physical function in these patients. At present, most related studies focus on patients with advanced KOA, and there are few studies on patients in early and middle stages. This study aims to apply the plantar pressure detection and human joint point identification technology to explore the characteristics of body posture and plantar pressure distribution in the early and middle-term KOA patients. Materials and Methods: Data from 38 middle and early KOA patients (age =54.58 ± 7.32 years) and 28 healthy volunteers (age =54.93 ± 7.90 years including), lower limb weight bearing, peak foot pressure distribution, pressure center (center of pressure [CoP]) offset, offset area, Q angle, pelvic position, spine offset, and other data were compared by statistical analysis of independent sample t-test and Pearson’s Chi-square test. Result: The results showed that the foot pressure in the early and mid-term KOA patients tended to be distributed in the medial heel, and the body CoP swing range was smaller than that in the control group (P < 0.05). In addition, patients in the KOA group had a larger left Q angle than the control group and had a smaller rate of right pelvis bias (P < 0.05). There was no statistical difference in lower limb weight bearing and spinal posture between the two groups. Conclusion: In standing conditions, patients in the KOA group have exhibited abnormal postural patterns and foot pressure distribution in the early and middle stages compared with healthy volunteers. Assessment of plantar pressure distribution, pelvic position, and positioning of lower limb joints may be important for evaluating patients with KOA. Keywords: Knee osteoarthritis, Plantar pressure, Posture