• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• 제17권2호
• /
• pp.131-143
• /
• 2007

The purpose of this study was to compare the ground reaction forces and plantar pressure variables among three different safety shoes (Type 1: ergonomically designed and high quality shoes, 2: curved and cushioned safety hoes, and 3: regular safety shoes) and to find the effect of insole during walking. Ten healthy subjects were recruited for this study. The ground reaction force was measured using a 3 dimensional motion analysis system. Plantar pressures were measured Pedar Mobile foot pressure scan system. The ground reaction force variables were not significantly different among three different shoe types and insole conditions. After insertion insole, plantar pressure distributions were improved. These results suggest that the type 1 safety shoes was superior than other safety shoes in the statistics, and applying insole could be a possible method to prevent fatigue of lower extremity and musculoskeletal disorders. Further studies are needed to find the effect of ergonomically designed safety shoes design and insole on practical value prevention of musculoskeletal disorder, fatigue and satisfaction of workers.

• Korean Journal of Applied Biomechanics
• /
• 제28권1호
• /
• pp.45-54
• /
• 2018

Objective: The purpose of this study was to investigate the effect of foot strengthening exercise program and functional insoles on joint angle and plantar pressure in elderly women. Thirteen elderly women who were enrolled in a university senior citizens academy of a metropolitan city in 2017 were divided into two groups: exercise group with functional insole (n=7) and exercise group without functional insole (n=6). Method: Three-dimensional motion analysis and Pedar-X were performed to compute the joint angle and the foot plantar pressure, respectively. Two-way repeated measure ANOVA was conducted to compare dependent variables within and between groups. The significance level was set at ${\alpha}=.05$. Results: The range of motion (ROM) of the ankle, knee, and hip joints in the exercise group with functional insole increased significantly more than the exercise group without functional insole. In both the experimental group and the comparison group, the maximum foot plantar pressure and the mean foot plantar pressure were decreased, but the comparison group without functional insole showed more decrease. Since the experimental group demonstrated greater pressure than the comparison group in the contact area (forefoot, midfoot), it was distributed over a greater area. Conclusion: The results of this study suggest that participation in foot strengthening exercises and using a functional insole has more positive effects than foot strengthening exercises alone on the joint angle and plantar pressure in elderly women. Increased foot plantar pressure led to an increased contact area (forefoot, midfoot) for distribution of the foot plantar pressure, but the effect of reducing the maximum and average plantar pressures was incomplete. However, wearing functional insoles along with exercise, could help in improving the stability of the joints, by increasing the range of motion, and could help the elderly in movement of the muscles more effectively, leading to an improvement in gait function.

• Physical Therapy Korea
• /
• 제8권3호
• /
• pp.35-41
• /
• 2001

In-shoe measurement systems allow the clinician and researcher to examine the pressure parameters within the shoe. The purpose of this study was to investigate the test-retest reliability of plantar pressures using the Parotec system over speeds and plantar regions. Seventeen healthy subjects were recruited for the study. Sampling rate was 100 Hz, and data of six variables (pressure on medial heel, lateral heel, 1st metatarsal head, 5th metatarsal head, and great toe and total impulse) were collected in four different gait speed (1.0 m/sec, 1.5 m/sec, 2.0 m/sec, and comfortable walking speed) in each day. The result indicates fair to excellent reliability between the two day test. Intraclass correlation coefficients (ICCs) ranged from .693 to .979, and range of reliability was similar depending on the speed and plantar region. In most cases, data recorded by the Parotec systems provide good evidence for the reliability.

• Korean Journal of Applied Biomechanics
• /
• 제30권4호
• /
• pp.321-335
• /
• 2020

Objective: The purpose of this study was to investigate the effect of neck traction and foot type on plantar pressure distribution during walking. Method: Total of 24 data were collected from women working with a computer for more than 6 hours every day. Three groups by foot type were divided: Pes Planus, normal foot, and Pes Cavus. Depending on the foot type and cervical traction, plantar pressure variables were measured; CA, MF, PP, and CT. Each variable was divided into 12 masks. MANOVA was performed for the difference of plantar pressure variables by foot type, and a paired t-test was performed for the cervical traction within groups. Results: The total CA decreased in the Pes Planus (p<.001) and Pes Cavus (p<.05) groups. MF increased in the big toe (p<.01) and 2nd toe (p<.05) of the normal foot, and MF-3rd metatarsal decreased (p<.01). The MF-2nd toe (p<.01) and 3rd toe (p<.05) of Pes Cavus decreased. The PP decreased in 2nd toe (p<.05), 3rd toe (p<.01), and 4th toe (p<.05) of the Pes Cavus. In normal foot, the PP-3rd metatarsal (p<.05) and PP-4th metatarsal (p<.01) reduced. In Pes Planus, PP decreased in the hindfoot (p<.05). In Pes Cavus group wearing a neck-tractor, the CT-hindfoot increased (p<.05). Conclusion: There was a significant change in the plantar pressure change by foot type after neck traction. When walking with a neck-tractor, the heel impact was alleviated in the Pes Planus, and the Pes Cavus showed the smooth and effective propulsion in the push-off. Overall, weight acceptance was effectively performed when walking with neck-traction. It was also found that the neck-tractor corrects the alignment of the neck, thereby creating a more stable gait pattern.

• Physical Therapy Korea
• /
• 제20권4호
• /
• pp.55-64
• /
• 2013

The first purpose was to identify the plantar pressure distributions (peak pressure, pressure integral time, and contact area) during level walking, and stair ascent and descent in asymptomatic flexible flatfoot (AFF). The second purpose was to investigate whether peak pressure data during level walking could be used to predict peak pressure during stair walking by identifying correlations between the peak pressures of level walking and stair walking. Twenty young adult subjects (8 males and 12 females, age $21.0{\pm}1.7$ years) with AFF were recruited. A distance greater than 10 mm in a navicular drop test was defined as flexible flatfoot. Each subject performed at least 10 steps during level walking, and stair ascent and descent. The plantar pressure distribution was measured in nine foot regions using a pressure measurement system. A two-way repeated analysis of variance was conducted to examine the differences in the three dependent variables with two within-subject factors (activity type and foot region). Linear regression analysis was conducted to predict peak pressure during stair walking using the peak pressure in the metatarsal regions during level walking. Significant interaction effects were observed between activity type and foot region for peak pressure (F=9.508, p<.001), pressure time integral (F=5.912, p=.003), and contact area (F=15.510, p<.001). The regression equations predicting peak pressure during stair walking accounted for variance in the range of 25.7% and 65.8%. The findings indicate that plantar pressures in AFF were influenced by both activity type and foot region. Furthermore the findings suggest that peak pressure data during level walking could be used to predict the peak pressure data during stair walking. These data collected for AFF can be useful for evaluating gait patterns and for predicting pressure data of flexible flatfoot subjects who have difficulty performing activities such as stair walking. Further studies should investigate plantar pressure distribution during various functional activities in symptomatic flexible flatfoot, and consider other predictors for regression analysis.

• Korean Journal of Applied Biomechanics
• /
• 제23권1호
• /
• pp.25-35
• /
• 2013

This study examined 24 right-handed amateur baseball players. Twelve who had played baseball for more than 6 years were grouped as skilled players, while 12 who had played for 1-3 years were the unskilled player group. The swing motion was divided into four event phases: stance, backswing, impact, and follow-through. The mean and maximum plantar pressure, center of pressure, and ground reaction force were measured during each event phase. The mean and standard deviations for each variables were calculated and differences were validated with the independent sample t-test. A p-value <0.05 was considered statistically significant. The results were as follows. 1)The ideal stance is a stable, balanced position with more than 65% of weight on the right foot. There was significant difference in mean left plantar pressure, while the maximal plantar pressure and mean right plantar pressure did not differ significant. 2)The effective backswing of a skilled player is comprised a rightward shift in weight to build maximum energy. More than 90% of the weight was on the right foot. There was a significant difference in the mean left plantar pressure, while the maximal plantar pressure and mean right plantar pressure did not differ significantly. 3) For an effective impact, a rapid shift in weight to the left foot is essential, so that a power hit is obtained. Significant difference in the mean and maximum plantar pressures of both feet were observed. 4)Follow-through requires wight balance, more on the right than the left, without leaning leftward. There was no significant difference in the mean or maximum plantar pressure. 5)The center of plantar pressure should move from the center of the foot to the toe. 6)The analyses of the ground reaction force suggest that a good swing involves a gradual shift in weight to the right side and a rapid leftward shift at impact. Good balance, with the center of gravity on the right side at follow-through, is also required.

• Annals of Rehabilitation Medicine
• /
• 제39권6호
• /
• pp.897-904
• /
• 2015

Objective To investigate differences in plantar pressure distribution between a normal gait and unpredictable slip events to predict the initiation of the slipping process. Methods Eleven male participants were enrolled. Subjects walked onto a wooden tile, and two layers of oily vinyl sheet were placed on the expected spot of the 4th step to induce a slip. An insole pressure-measuring system was used to monitor plantar pressure distribution. This system measured plantar pressure in four regions (the toes, metatarsal head, arch, and heel) for three events: the step during normal gait; the recovered step, when the subject recovered from a slip; and the uncorrected, harmful slipped step. Four variables were analyzed: peak pressure (PP), contact time (CT), the pressure-time integral (PTI), and the instant of peak pressure (IPP). Results The plantar pressure pattern in the heel was unique, as compared with other parts of the sole. In the heel, PP, CT, and PTI values were high in slipped and recovered steps compared with normal steps. The IPP differed markedly among the three steps. The IPPs in the heel for the three events were, in descending order (from latest to earliest), slipped, recovered, and normal steps, whereas in the other regions the order was normal, recovered, and slipped steps. Finally, the metatarsal head-to-heel IPP ratios for the normal, recovered, and slipped steps were $6.1{\pm}2.9$, $3.1{\pm}3.0$, and $2.2{\pm}2.5$, respectively. Conclusion A distinctive plantar pressure pattern in the heel might be useful for early detection of a slip event to prevent slip-related injuries.

• Korean Journal of Applied Biomechanics
• /
• 제31권3호
• /
• pp.189-198
• /
• 2021

Objective: The aim of this study is to investigate the effect of biomechanical variables on gait according to indoor and outdoor environmental conditions in elderly women at risk of falling. Method: 26 elderly women aged 70 years or older, and consisted of 13 elderly people with a walking speed of less 1.0 m/s and 13 people in the fall risk group as normal groups. Depending on the purpose of the study, physical examination and psychological questionnaire were prepared, and then walking was performed in an indoor/outdoor environment, and the gait pattern, muscle activity, and plantar pressure results were compared and analyzed in the elderly females through a 2 group × 2 environment 2-way repeted ANOVA analysis. Results: The gait variable showed an interaction effect the cadence. The muscle variables showed interaction effects in the rectus femoris and tibialis anterior muscles, and the interaction effects of the plantar pressure variables were confirmed in the forefoot and midfoot of the contact area, and the midfoot of the mean pressure. Conclusion: These results indicate that both groups are exposed to falls risk when gait in an outdoor environment, but the fall risk group has a higher risk of falls in both the gait pattern, muscle activity, and plantar pressure variables. The results of this study are considered to be helpful as basic data and development of exercise programs to prevent falls.

• Korean Journal of Applied Biomechanics
• /
• 제27권3호
• /
• pp.229-238
• /
• 2017

Objective: The purpose of this study was to identify the effects of taping therapy and inner arch support on pes planus lower extremity alignment and gait. Method: The study was conducted on 13 women in their 20s who had pes planus and no gait problems. Independent variables were the condition of wearing basic socks (S1) and the condition of wearing socks with taping therapy and inner arch support (S2). The dependent variables were resting calcaneal stance position (RCSP), plantar pressure distribution during gait, and underlying and medial longitudinal arch angle measured using radiography. Statistical analysis was performed using the Wilcoxon test with SPSS 23.0 for comparison of S1 and S2. Results: In the RCSP measurement, the angle range of S2 changed to normal. Meary's angle appeared to be less than the angle of S1, indicating alleviation of the degree of pes planus. The calcaneal pitch angle increased at S2 from that at S1. The plantar pressure distribution was divided into four areas (toe, forefoot, midfoot, and hindfoot). At S2, the maximum pressure increased in the toe and midfoot. The maximum force increased significantly in the toe and midfoot but decreased significantly in the forefoot and hindfoot. In addition, the contact area increased overall especially at the midfoot and hindfoot. Contact time decreased in the toe and forefoot, but increased in the midfoot and hindfoot. Conclusion: Taping therapy and inner arch support showed structural improvement of the pes planus. In addition, the force and pressure applied to the foot during walking are distributed evenly in the area of the sole, thus positively affecting walking.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• 제13권3호
• /
• pp.1153-1160
• /
• 2012

This study was intended to implement ankle joint dorsi flexion training against ankle muscule strength weakening that erodes stroke patients' gait performance to examine the effect of the training on stroke patients' plantar pressure and gait ability. In this study, 36 stroke patients diagnosed with stroke due to cerebral infarction or cerebral hemorrhage were divided to measure 10MWS which are stroke patients' gait variables maximum plantar pressure by area of the sole by collecting data using an F-scan system during gait. Given these results of the study, compared to other training groups, the ankle muscule strength reinforcing training group showed statistically significant increases of maximum plantar pressure in the great toe, the toe and the first metatasal areas too and thus it can be said that this training increases forward thrust during stroke patients' foot end taking off and positively affects stroke patients' ability to perform gait.