Knee osteoarthritis at the early stage: The four-week effect of lateral wedge insole on pain and risk of falls.

Background: Knee osteoarthritis (KOA) is associated with a decrease in function, increase in pain and risk of falls. Lateral wedge insole (LWI) is commonly prescribed in KOA to improve pain and function. Our study aimed to 1) evaluate the clinical symptoms and risk of falls in early KOA and compare with controls; 2) evaluate the immediate and four-week effect of LWI. Methods: A sample of 20 Persian dwelling individuals with early KOA and 19 matched controls were recruited. Pain with Visual Analogue Scale (VAS), Quality of life (QOL) with the knee injury and osteoarthritis outcome score, risk of falls with the Timed Up and Go (TUG) and static One-leg Balance (OLB) tests were assessed. The four-week effect of 5º LWI was considered for individuals with KOA. Independent t-test was done to report the between-group differences, and paired t-test was used to report the four-week effect of LWI. Results: At baseline, statistically significant higher scores for pain, lower scores for QOL, and higher risk of falls were observed in KOA compared to controls (p< 0.001). A significant statistical decrease was observed in pain, and risk of falls, and an increase in QOL in KOA after four-week effect of LWI compared to baseline (p< 0.001). Conclusion: People with early KOA showed higher pain and lower level of QOL that were associated with higher risk of falls. LWI may have the potential to improve clinical symptoms and reduce the risk of falls at the early stage of KOA.

Fatigue Effect on Linear Center of Pressure Measures during Gait in People with Flat Feet.

BACKGROUND: Flat foot, as one of the common foot deformities can affect gait biomechanics and risk of lower extremity injury. Fatigue, as a high load task, can also change biomechanical parameters of locomotion. Studying normal and flat footed individuals under high load tasks such as fatigue can elucidate their differences more easily. OBJECTIVES: In this study, center of pressure (CoP) changes were studied between individuals with flat and normal feet after fatigue. CoP is one of the important gait measures which can show various biomechanical behaviors of different foot shapes. METHODS: Seventeen subjects with normal feet and 17 with flat feet walked across two force plates before and after a functional fatigue protocol. Standard deviation of CoP in mediolateral direction (SD of CoPx) and in anteroposterior direction (SD of CoPy), overall mean velocity of CoP and length of CoP construction line of both groups were analyzed. The values of SD of CoPy and length of CoP construction line were normalized to individual foot lengths prior to statistical analyses. RESULTS: There were no significant between-subject effects for all CoP measures. The only significant finding was the within-subject effect for the SD of CoPy (P = 0.008) with a large effect size (partial eta squared = 0.21). Fatigue resulted in lower SD of CoPy in both groups. CONCLUSIONS: Lower SD of CoPy indicates less fluctuation of CoPy and a probable less center of mass movement which could reduce the risk of injury. Furthermore, the similar fatigue response in both groups of individuals with normal and flat feet indicates a similar biomechanical behavior despite their different foot arch height.