Influence of using knee sleeve and lateral wedge insole on knee loading among healthy individuals during stair negotiation

Background: For individuals with knee osteoarthritis (OA), stair negotiation is a challenging task and the first task during which they report pain due to the high knee loading required. The use of lateral wedge insole (LWI) has been found to reduce loading in patients with OA but not to reduce pain, whereas the use of knee sleeve has been shown to result in good pain reduction. Understanding the effect of combining LWI and knee sleeve use on healthy individuals before testing on individuals with knee OA is an important step. Research question: The current study aimed to evaluate the effect of combining the use of LWI and knee sleeve and compare the results with the application of each treatment separately and with the control condition. Methods: This randomised cross-over study included 17 healthy participants who underwent 3D gait analysis. Participants performed ascending and descending stair activities with the following four treatment conditions: five-degree LWI, off-the-shelf knee sleeve, both LWI and knee sleeve and control condition. External knee adduction moment (EKAM) and knee frontal plane range of motion (ROM) were evaluated as primary outcomes. Repeated measure ANOVA or the Friedman test was selected based on meeting the assumption followed by multiple pairwise comparisons with Bonferroni correction. Results: In general, the use of LWI reduced the first peak EKAM significantly (p < 0.001) compared to the control condition in stir ascending (12% reduction) but not in stair descending (p > 0.05). Interestingly, knee sleeve use did not result in any reduction in the first peak EKAM compared to the control or any other condition. However, knee sleeve use led to a significant reduction in the knee frontal plane ROM during stair descending. The combined treatment was not superior to the LWI use when compared to control in the EKAM reduction. Significance: Combined knee sleeve and LWI use was not superior to LWI use alone in reducing the knee loading, but it may be beneficial for individuals with knee OA since it helped in reduction of the knee frontal plane ROM during stair descending. Importantly, the effect of LWI use or any other treatment must be investigated for each different activity, and the results found in one activity must not be generalised across other activities.