Effect of Walking Speeds on Complexity of Plantar Pressure Patterns

Ben-Yi Liau,Fu-Lien Wu,Ayman A Mohamed,Yameng Li,Yih-Kuen Jan,Chi-Wen Lung,Dan Selişteanu

doi:10.1155/2021/6571336

Abstract

Various walking speeds may induce different responses on the plantar pressure patterns. Current methods used to analyze plantar pressure patterns are linear and ignore nonlinear features. The purpose of this study was to analyze the complexity of plantar pressure images after walking at various speeds using nonlinear bidimensional multiscale entropy (MSE2D). Twelve participants (age: 27.1 ± 5.8 years; height: 170.3 ± 10.0 cm; and weight: 63.5 ± 13.5 kg) were recruited for walking at three speeds (slow at 1.8 mph, moderate at 3.6 mph, and fast at 5.4 mph) for 20 minutes. A plantar pressure measurement system was used to measure plantar pressure patterns. Complexity index (CI), a summation of MSE2D from all time scales, was used to quantify the changes of complexity of plantar pressure images. The analysis of variance with repeated measures and Fisher’s least significant difference correction were used to examine the results of this study. The results showed that CI of plantar pressure images of 1.8 mph (1.780) was significantly lower compared with 3.6 (1.790) and 5.4 mph (1.792). The results also showed that CI significantly increased from the 1st min (1.780) to the 10th min (1.791) and 20th min (1.791) with slow walking (1.8 mph). Our results indicate that slow walking at 1.8 mph may not be good for postural control compared with moderate walking (3.6 mph) and fast walking (5.4 mph). This study demonstrates that bidimensional multiscale entropy is able to quantify complexity changes of plantar pressure images after different walking speeds.

Highlights

Postural control is a complex process for maintaining the orientation and balance of human body during upright position and movements in activities of daily living [1,2,3]
We examined the change of complexity of plantar pressure images in response to different walking speeds by using bidimensional multiscale entropy (MSE2D). e study aimed to examine the hypothesis of fast walking speeds at 3.6 and 5.4 mph which would reduce complexity of plantar pressure images compared with slow walking speed at 1.8 mph. e findings from bidimensional multiscale entropy could help understand the effect of various walking speeds on plantar pressure and postural control
During the walking speed of 1.8 mph, complexity index (CI) values significantly increased with walking speed (p < 0.05). ere was a trend that CI increased with time at 1st min, 10th min, and 20th min

Summary

Introduction

Postural control is a complex process for maintaining the orientation and balance of human body during upright position and movements in activities of daily living [1,2,3]. Various methods have been used to evaluate human postural control, including center of mass, center of gravity, center of pressure, ground reaction force, and plantar pressure patterns [1,2,3]. Common analyses of plantar pressure patterns include average pressure, peak pressure, force value, and contact area [6, 7]. Researchers have indicated that these traditional methods may not fully characterize abnormal changes of postural control associated with aging or agingrelated conditions [4, 5]. Research findings showed that using nonlinear analyses (e.g., irregularity and complexity) may be more effective than linear analyses to detect pathological changes of biological signals [8,9,10]. Costa et al proposed a new nonlinear algorithm multiscale entropy

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Results

Discussion

Conclusion