Plantar Pressure Measurement System Research Articles

Equilibrio y carga plantar en diferentes técnicas de sentadilla

This research aims to analyze dynamic balance and plantar load in different squatting techniques, providing insights into the influence of these exercises in practitioners who incorporate weightlifting into their training routines. A sample of 21 subjects engaged in activities involving three squatting techniques: Back Squat (BS), Front Squat (FS), and Overhead Squat (OHS) was analyzed. Participants assumed a baseline posture and performed exercises with approximately 50% RM for each squatting technique. A plantar pressure measurement system was used to assess center of pressure (COP) displacement, peak pressure (PP), and plantar load in different regions of the foot. One-way Welch's ANOVA considering COP displacement, PP, and percentage of force for each foot region was measured. The results showed no significant effect of the squatting technique on COP trajectory during the exercises. However, a significant interaction was observed between the squatting technique and PP compared to the static balance situation. All three squats resulted in higher PP than static balance, with OHS exhibiting the highest values, followed by FS and BS. No significant differences were found between the squat techniques. These findings suggest that different squat techniques can influence plantar load, but do not affect the trajectory of the COP during the execution of the exercise. The heel region generated the greatest plantar load among the three squat techniques and should receive greater attention during the squat and its variations. This information can assist in prescribing exercises and developing more efficient training programs for weightlifters.

Donor-site morbidity following arthroscopic anterior cruciate ligament reconstruction using peroneus longus tendon autograft.

Peroneus longus has proved to be a promising graft for ACL reconstruction due to its high tensile strength, and ease of harvesting. While multiple studies have assessed the functional outcomes of the knee after ACL reconstruction using peroneus longus autograft, we aimed to evaluated donor site morbidity among the Indian population. This was a prospective, longitudinal, descriptive study conducted at a tertiary care hospital. Preoperative AOFAS and Karlsson-Peterson scores were obtained, and patients were followed up after surgery for a period of 6-months using the same scoring systems and strength testing with a hand-held Chatillon MSE-100-M dynamometer. Pedobarographs were done using Diers Pedoscan Plantar Pressure Measurement System on a subset of seven patients. 20 patients participated in the study. Mean AOFAS and Karlsson-Peterson scores pre-operatively were 99.7 ± 1.34 and 98.5 ± 4.62 respectively. On completing 6- months of follow-up these scores were found to be 95.6 ± 9.43 and 88.75 ± 18.42 respectively. Deterioration of mean evertor strength was noted at all follow-ups compared to the opposite side. Static pedobarographs showed significant decreased in total surface area of contact and pressure over the posterior aspect of the operated side by 3-months which improved later at 6-months. Dynamic pedobarographs showed decreased mean average plantar pressure while walking on the operated side and significant increase in mean surface area of contact of the operated side (191.886±22.678 cm2) at 6-months of follow-up compared to the opposite side (184.471 ± 22.218 cm2). Five patients showed deviation of the point of maximum pressure while walking on the operated foot making it lateral to the COP with increased lateral plantar/ medial plantar pressure ratio. While the use of peroneus longus tendon autografts in arthroscopic ACL reconstruction does not seem problematic on short-term subjective assessment, there is objective evidence in keeping with evertor weakness, weakness of first ray plantar flexion and possible ankle instability. Level lll.

Injury of flexor halluics longus tendon in amateur marathon runners results in abnormal plantar pressure distribution: observational study

ObjectiveTo analyze the changes of plantar pressure in amateur marathon runners with flexor halluics longus (FHL) tendon injury using the Medtrack-Gait plantar pressure measurement system, and to explore whether the plantar pressure data can be used as an index for the diagnosis of injury.MethodsA total of 39 healthy amateur marathon runners without any ankle joint symptoms were recruited. Dynamic and static plantar pressure data were measured using the pressure plate of Medtrack-Gait. According to MRI imaging findings, whether the FHL tendon was injured or not was judged, and the dynamic and static data were divided into the injury group and control group. The data with statistically significant differences between the two groups were used to make the receiver operating characteristic (ROC) curve.ResultThe maximum contact area (PA) of the first metatarsal(M1) region, the maximum load-bearing peak value (PW) and the time pressure integral (PMPTI) of the second metatarsal(M2) region in the injury group were lower than those in the control group, respectively (P < 0.05). The maximum contact area (PA) of the fifth metatarsal(M5) region was higher than that in the control group (P < 0.05). The area under curve (AUC) value of the ROC curve of the PA of M1 region, the PW and PMPTI of M2 region were statistically (P < 0.05).ConclusionFHL tendon injury resulted in decreased PA in M1, decreased PW and PMPTI in M2, and increased PA in the M5 region, suggesting that FHL tendon injury resulted in a force shift from the medial to the lateral side of the foot. The PA of M1, PW and PMPTI of M2 have certain diagnostic value for early FHL injury in amateur marathon runners.

Analysis of mechanical characteristics of walking and running foot functional units based on non-negative matrix factorization.

Objective: To explore the characteristics of Non-Negative Matrix Factorization (NNMF) in analyzing the mechanical characteristics of foot functional units during walking and running. Methods: Eighteen subjects (9 males and 9 females) were recruited, and the ground reaction force curves of each foot region during walking and running were collected using a plantar pressure measurement system. NNMF was used to extract the mechanical features of different foot regions and to determine the number of foot functional units. The differences between the base matrices of walking and running were compared by traditional t-tests, and the differences in coefficient matrices were compared by one-dimensional statistical parameter mapping. Results: 1) When the number of foot functional units for walking and running were both 2, the Variability Accounted For (VAF) by the matrix exceeded 0.90 (VAF walk = 0.96 ± 0.02, VAF run = 0.95 ± 0.04); 2) In foot functional unit 1, both walking and running exhibited buffering function, with the heel region being the main force-bearing area and the forefoot also participating in partial buffering; 3) In foot functional unit 2, both walking and running exhibited push-off function, with the middle part of the forefoot having a higher contribution weight; 4) In foot functional unit 1, compared to walking, the overall force characteristics of the running foot were greater during the support phase of the 0%-20% stage, with the third and fourth metatarsal areas having higher contribution weights and the lateral heel area having lower weights; 5) In foot functional unit 2, compared to walking, the overall force was higher during the beginning and 11%-69% stages of running, and lower during the 4%-5% and 73%-92% stages. During running, the thumb area, the first metatarsal area and the midfoot area had higher contribution weights than during walking; in the third and fourth metatarsal areas, the contribution weights were lower during running than during walking. Conclusion: Based on the mechanical characteristics of the foot, walking and running can both be decomposed into two foot functional units: buffering and push-off. The forefoot occupies a certain weight in both buffering and push-off functions, indicating that there may be a complex foot function transformation mechanism in the transverse arch of foot. Compared to walking, running completes push-off earlier, and the force region is more inclined towards the inner side of the foot, with the hallux area having a greater weight during push-off. This study suggests that NNMF is feasible for analyzing foot mechanical characteristics.

Gait phase recognition of multi-mode locomotion based on multi-layer perceptron for the plantar pressure measurement system

Gait phase recognition of multi-mode locomotion based on multi-layer perceptron for the plantar pressure measurement system

Evaluation of Different Pressure-Based Foot Contact Event Detection Algorithms across Different Slopes and Speeds.

If validated, in-shoe pressure measuring technology allows for the field-based quantification of running gait, including kinematic and kinetic measures. Different algorithmic methods have been proposed to determine foot contact events from in-shoe pressure insole systems, however, these methods have not been evaluated for accuracy, reliability against a gold standard using running data across different slopes, and speeds. Using data from a plantar pressure measurement system, seven different foot contact event detection algorithms based on pressure signals (pressure sum) were compared to vertical ground reaction force data collected from a force instrumented treadmill. Subjects ran on level ground at 2.6, 3.0, 3.4, and 3.8 m/s, six degrees (10.5%) inclined at 2.6, 2.8, and 3.0 m/s, and six degrees declined at 2.6, 2.8, 3.0, and 3.4 m/s. The best performing foot contact event detection algorithm showed maximal mean absolute errors of only 1.0 ms and 5.2 ms for foot contact and foot off, respectively, on level grade, when compared to a 40 N ascending and descending force threshold from the force treadmill data. Additionally, this algorithm was unaffected by grade and had similar levels of errors across all grades.

Characterization of the Kinetyx SI Wireless Pressure-Measuring Insole during Benchtop Testing and Running Gait.

This study characterized the absolute pressure measurement error and reliability of a new fully integrated (Kinetyx, SI) plantar-pressure measurement system (PPMS) versus an industry-standard PPMS (F-Scan, Tekscan) during an established benchtop testing protocol as well as via a research-grade, instrumented treadmill (Bertec) during a running protocol. Benchtop testing results showed that both SI and F-Scan had strong positive linearity (Pearson's correlation coefficient, PCC = 0.86-0.97, PCC = 0.87-0.92; RMSE = 15.96 ± 9.49) and mean root mean squared error RMSE (9.17 ± 2.02) compared to the F-Scan on a progressive loading step test. The SI and F-Scan had comparable results for linearity and hysteresis on a sinusoidal loading test (PCC = 0.92-0.99; 5.04 ± 1.41; PCC = 0.94-0.99; 6.15 ± 1.39, respectively). SI had less mean RMSE (6.19 ± 1.38) than the F-Scan (8.66 ±2.31) on the sinusoidal test and less absolute error (4.08 ± 3.26) than the F-Scan (16.38 ± 12.43) on a static test. Both the SI and F-Scan had near-perfect between-day reliability interclass correlation coefficient, ICC = 0.97-1.00) to the F-Scan (ICC = 0.96-1.00). During running, the SI pressure output had a near-perfect linearity and low RMSE compared to the force measurement from the Bertec treadmill. However, the SI pressure output had a mean hysteresis of 7.67% with a 28.47% maximum hysteresis, which may have implications for the accurate quantification of kinetic gait measures during running.

Fiber Bragg Gratings based smart insole to measure plantar pressure and temperature

Various foot complications can be easily avoided by continuous monitoring of foot plantar temperature and pressure. In this work, the design, characterization, and implementation of a Fiber Bragg Gratings (FBG) based smart insole capable of simultaneously measuring plantar pressure and temperature has been reported. The instrumented insole was tested and verified during static and gait exercises. The paper also provides a comparison of the developed optoelectronic-based solution with a commercially available and widely used plantar pressure measurement and analysis system and a lab-made, electronic sensor-based smart insole that can measure both plantar temperature and pressure. It was shown that even though the commercially available expensive system is very robust and highly precise due to many sensing units on the insole, the developed insole with a smaller number of sensors can provide both plantar temperature and pressure with reasonable precision while displaying both foot pressure and temperature maps, and gait cycle plots in real-time. The FBG-based solution is comfortable and safer than the other systems being compared. Thus, confirming the effectiveness of the proposed solution as an addition to the research area for detecting foot complications non-invasively using foot insoles.

Development of Intraoperative Plantar Pressure Measurement System Considering Weight Bearing Axis and Center of Pressure

To prevent postoperative complications in corrective surgery for foot deformities such as hallux valgus and pes planus, it is critical to quantitatively predict the postoperative standing-position plantar pressure distribution during the operation. The authors have previously proposed an intraoperative plantar pressure measurement system (IPPM) that allows for the measurement of a supine patient’s plantar pressure distribution that is equivalent to that in the standing position. This system consists of an IPPM device comprising of a force plate and pressure distribution sensor, an optical three-dimensional position measurement device, a navigation monitor, and a PC. The plantar pressure distribution in the standing position is reproduced by navigating the operator, as he or she presses the IPPM device against the patient’s sole so that the weight-bearing axis (floor reaction force vector) and femoral head center are as close to each other as possible. However, in our previous study, the reproducibility of the standing position plantar pressure distribution was insufficient. Therefore, in the present study, we add a navigational function that can be used to bring the centers of pressure in the standing position and under measurement, as well as to correct the IPPM’s self-weight in the measured force. The improved device was used in an experiment with nine healthy subjects, and the similarity of the plantar pressure distribution in the standing and supine positions was evaluated using normalized cross-correlation, yielding an average of 0.90. Furthermore, in an evaluation experiment with ten orthopedic surgeons, it was observed that using the system reproduced the plantar pressure distribution significantly better than when the system was not used. These results indicate that the present system can predict the plantar pressure distribution in the standing position. We believe that this system can contribute to reducing complications after foot surgery.

The Development of a Built-In Shoe Plantar Pressure Measurement System for Children.

There is a rapid increase in plantar pressure from the infant to toddler stage, yet little is known about the reasons for this change. More information about plantar pressure distribution can help clinicians identify early-stage foot-related diseases that may occur during transitions from childhood to adulthood. This information also helps designers create shoes that adapt to different needs. This research describes the development of a low-cost, built-in shoe plantar pressure measurement system that determines foot pressure distribution in toddlers. The study aimed to improve and provide data on pressure distribution during foot growth. This was accomplished by implementing a plantar pressure capacitive measurement system within shoes. The capacitive sensors were laminated using a copper tape sheet on plastic backing with adhesive, elastomer layers, and a combination of conductive and non-conductive fabrics. Constructed sensors were characterized using compression tests with repeated loads. Results demonstrated that the sensors exhibited rate-independent hysteresis in the estimation of pressure. This enabled a calibration model to be developed. The system can mimic more expensive plantar pressure measurement systems at lower fidelity. This emerging technology could be utilized to aid clinicians, researchers, and footwear designers interested in how pressure distribution changes from infants to toddlers.

Plantar Pressure Distribution Measurement System Based on PVDF Piezoelectric Senors

During people’s normal movement, the sole of foot is the only part of human body that contacts with the ground. The pressure information of sole directly reflects the physiological health and movement posture of human. A plantar pressure measurement system was designed with an insole type for measuring plantar pressure during normal movement. The insole embedded five PVDF piezoelectric film sensors, and then places the insole in the measured sports shoes. In order to obtain better pressure response effect, two small raised blocks were pasted under each piezoelectric film sensor to increase the sensitivity of the sensor. The plantar pressure data was sent to PC by wireless serial port. An intuitive and easy-to-use GUI interface was designed by the MATLAB software. The interface can display the pressure distribution at each point of the sole of both feet.

Effects of walking speeds and durations on the plantar pressure gradient and pressure gradient angle

BackgroundWalking exercise has been demonstrated to improve health in people with diabetes. However, it is largely unknown the influences of various walking intensities such as walking speeds and durations on dynamic plantar pressure distributions in non-diabetics and diabetics. Traditional methods ignoring time-series changes of plantar pressure patterns may not fully capture the effect of walking intensities on plantar tissues. The purpose of this study was to investigate the effect of various walking intensities on the dynamic plantar pressure distributions. In this study, we introduced the peak pressure gradient (PPG) and its dynamic patterns defined as the pressure gradient angle (PGA) to quantify dynamic changes of plantar pressure distributions during walking at various intensities.MethodsTwelve healthy participants (5 males and 7 females) were recruited in this study. The demographic data were: age, 27.1 ± 5.8 years; height, 1.7 ± 0.1 m; and weight, 63.5 ± 13.5 kg (mean ± standard deviation). An insole plantar pressure measurement system was used to measure plantar pressures during walking at three walking speeds (slow walking 1.8 mph, brisk walking 3.6 mph, and slow running 5.4 mph) for two durations (10 and 20 min). The gradient at a location is defined as the unique vector field in the two-dimensional Cartesian coordinate system with a Euclidean metric. PGA was calculated by quantifying the directional variation of the instantaneous peak gradient vector during stance phase of walking. PPG and PGA were calculated in the plantar regions of the first toe, first metatarsal head, second metatarsal head, and heel at higher risk for foot ulcers. Two-way ANOVA with Fisher’s post-hoc analysis was used to examine the speed and duration factors on PPG and PGA.ResultsThe results showed that the walking speeds significantly affect PPG (P < 0.05) and PGA (P < 0.05), and the walking durations does not. No interaction between the walking duration and speed was observed. PPG in the first toe region after 5.4 mph for either 10 or 20 min was significantly higher than 1.8 mph. Meanwhile, after 3.6 mph for 20 min, PPG in the heel region was significantly higher than 1.8 mph. Results also indicate that PGA in the forefoot region after 3.6 mph for 20 min was significantly narrower than 1.8 mph.ConclusionsOur findings indicate that people may walk at a slow speed at 1.8 mph for reducing PPG and preventing PGA concentrated over a small area compared to brisk walking at 3.6 mph and slow running at 5.4 mph.

Sarcopenia: Body Composition and Gait Analysis

BackgroundAge-induced sarcopenia negatively affects walking stability and increases the risk of falls, which is the leading cause of accidental death in the elderly.ObjectiveThis study aimed to analyze and contrast body composition and gait characteristics in those with sarcopenia in relation to healthy controls to shed some light on the prevention of falls in elderly patients with sarcopenia.Materials and MethodsIn this study, 68 community dwellers were scanned by the Hologic QDR-4500A Dual-energy X-ray absorptiometry (DXA). The appendicular lean mass index (ALMI) results were used to distinguish the normal participants from those with sarcopenia: 24 in the sarcopenia group, and 44 into the normal group. The participants were asked to undergo gait analysis on a plantar pressure measurement system. Statistical analysis was conducted to contrast both groups' gait and butterfly parameters from their gait test, and then a gait forward dynamics method was performed to quantify the analysis for both groups.ResultsThe ALMI of the female was not related to their age (r = 0.06) while that of the male was weakly related (r = 0.17). Body mass index (BMI) from both groups was normal, although with a statistically greater BMI from the normal group compared with sarcopenia (p < 0.001). Greater values and significant differences were found in step length and stride length from the normal elderly group (p < 0.01), and so was the length of the gait line and single support line (p < 0.05). Gait forward dynamics analysis results showed no motor neural or musculoskeletal disorders in their gait performance from the sarcopenia group.ConclusionFor the elderly, age did not largely affect the ALMI, BMI, or T-score, but BMI and ALMI were strongly correlated. In this study, significant differences were found in certain gait parameters between the elderly with sarcopenia and the normal elderly, which were related to absolute muscle strength, suggesting that sarcopenia was a disease mainly caused by decreased muscle mass. In addition, when abnormities were identified in step length, stride length, length of gait line, or length of single support line, it is proposed to take a DXA scan to confirm whether the elderly suffer from sarcopenia.

A Low-Cost Approach of Plantar Pressure Measurement for Mobility Assistance in Paraplegia

This paper is aimed to develop a low-cost foot plantar pressure measurement system for mobility assistance in paraplegic patients. Force sensing foot is used to measure plantar pressure, which gives the interaction of human foot and ground of the waver while sit to stand, stand to sit, and analyze. For the purpose of determining the location of the most intense pressure points on the sole of the foot, research was undertaken on healthy individuals of varying weights. The proposed method is compared to an existing process that uses force-sensitive resistors (FSRs) placed below the foot for detecting the user intent of the motion. Because of the recent rise in the usage of lower-limb exoskeletons, plantar pressure has emerged as a viable parameter for gait rehabilitation. Foot sensors developed in the study for the control of exoskeleton are inserted into the shoe. The design of a low-cost plantar pressure measurement system to support the paraplegic patients is presented.

Design and performance evaluation of multifunctional midsole using functionally gradient wave springs produced using multijet fusion additive manufacturing process

Additive manufacturing (AM) is getting more attention and is considered a better choice of fabrication in almost every industry due to its unlimited design freedom, optimization, light-weight and customization. Currently, manufacturing constraints, limited design freedom and customization issues restrict manufacturers from designing specific shoes for each particular application e.g., walking, running, hiking, sports, etc. However, AM can design and fabricate a multifunctional, usable single shoe-midsole for all aforementioned applications. This study aims to design a multifunctional shoe midsole incorporated with functionally gradient wave springs (FGWS) at the critical areas of foot pressure (heel, forefoot and toe) measured using the F-scan system (insole plantar pressure measurement system). The non-critical areas were designed by a gradient cellular structure with graded unit cells as per load requirement. The designed midsole with FGWS was printed by an HP MultiJet Fusion printer using PA 12 (polyamide). A LISA printer (selective laser sintering) using TPU (thermoplastic polyurethane) material was also used to check its manufacturability. Compression testing, each spring up to 80% of its compressible distance studied the load-bearing capacity, energy absorption, stiffness and cushioning properties. The load-bearing capacity of FGWS was decreased and energy absorption was enhanced by compressing each spring with EVA (Ethylene-vinyl acetate) foam while traditionally manufactured non-contact metal wave springs showed a lower load-bearing capacity than AM (contact) wave springs. Moreover, the fatigue properties of both were compared after 100 cycles of compression, which found a good response of AM wave springs. Experimental compression results revealed a gradual smooth response of load against compression, i.e., cushioning and more energy absorption, validated by finite element analysis (FEA) with very little deviation.

Plantar pressure measurement system based on piezoelectric sensor: a review

PurposePlantar force is the interface pressure existing between the foot plantar surface and the shoe sole during static or dynamic gait. Plantar force derived from gait and posture plays a critical role for rehabilitation, footwear design, clinical diagnostics and sports activities, and so on. This paper aims to review plantar force measurement technologies based on piezoelectric materials, which can make the reader understand preliminary works systematically and provide convenience for researchers to further study.Design/methodology/approachThe review introduces working principle of piezoelectric sensor, structures and hardware design of plantar force measurement systems based on piezoelectric materials. The structures of sensors in plantar force measurement systems can be divided into four kinds, including monolayered sensor, multilayered sensor, tri-axial sensor and other sensor. The previous studies about plantar force measurement system based on piezoelectric technology are reviewed in detail, and their characteristics and performances are compared.FindingsA good deal of measurement technologies have been studied by researchers to detect and analyze the plantar force. Among these measurement technologies, taking advantage of easy fabrication and high sensitivity, piezoelectric sensor is an ideal candidate sensing element. However, the number and arrangement of the sensors will influence the characteristics and performances of plantar force measurement systems. Therefore, it is necessary to further study plantar force measurement system for better performances.Originality/valueSo far, many plantar force measurement systems have been proposed, and several reviews already introduced plantar force measurement systems in the aspect of types of pressure sensors, experimental setups for foot pressure measurement analysis and the technologies used in plantar shear stress measurements. However, this paper reviews plantar force measurement systems based on piezoelectric materials. The structures of piezoelectric sensors in the measurement systems are discussed. Hardware design applied to measurement system is summarized. Moreover, the main point of further study is presented in this paper.

A fundamental study of a wearable foot plantar pressure measurement system for diagnosing vestibular disorders

A fundamental study of a wearable foot plantar pressure measurement system for diagnosing vestibular disorders

Development of Plantar Pressure Measurement System and Personal Classification Study based on Plantar Pressure Image

Development of Plantar Pressure Measurement System and Personal Classification Study based on Plantar Pressure Image

Estimation of Various Walking Intensities Based on Wearable Plantar Pressure Sensors Using Artificial Neural Networks.

Walking has been demonstrated to improve health in people with diabetes and peripheral arterial disease. However, continuous walking can produce repeated stress on the plantar foot and cause a high risk of foot ulcers. In addition, a higher walking intensity (i.e., including different speeds and durations) will increase the risk. Therefore, quantifying the walking intensity is essential for rehabilitation interventions to indicate suitable walking exercise. This study proposed a machine learning model to classify the walking speed and duration using plantar region pressure images. A wearable plantar pressure measurement system was used to measure plantar pressures during walking. An Artificial Neural Network (ANN) was adopted to develop a model for walking intensity classification using different plantar region pressure images, including the first toe (T1), the first metatarsal head (M1), the second metatarsal head (M2), and the heel (HL). The classification consisted of three walking speeds (i.e., slow at 0.8 m/s, moderate at 1.6 m/s, and fast at 2.4 m/s) and two walking durations (i.e., 10 min and 20 min). Of the 12 participants, 10 participants (720 images) were randomly selected to train the classification model, and 2 participants (144 images) were utilized to evaluate the model performance. Experimental evaluation indicated that the ANN model effectively classified different walking speeds and durations based on the plantar region pressure images. Each plantar region pressure image (i.e., T1, M1, M2, and HL) generates different accuracies of the classification model. Higher performance was achieved when classifying walking speeds (0.8 m/s, 1.6 m/s, and 2.4 m/s) and 10 min walking duration in the T1 region, evidenced by an F1-score of 0.94. The dataset T1 could be an essential variable in machine learning to classify the walking intensity at different speeds and durations.

Effect of Walking Speeds on Complexity of Plantar Pressure Patterns

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.