• 한국산업보건학회지
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• 제19권1호
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• pp.25-29
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• 2009

The purpose of this study was to investigate the effect of two different lifting posture on the plantar foot pressure, force and COP(center of pressure) trajectory path during object lifting. Fourteen healthy adults who had no musculoskeletal disorders were instructed to lift with two postures(stoop and squat) and two object weights(empty box and 10 kg box). Plantar foot pressures, forces and COP trajectory path were recorded by the F-mat system(Tekscan, Boston, USA) during object lifting with barefoot. Plantar foot surface was defined as seven regions for pressure measurement; two toe regions, three forefoot regions, one midfoot region and one heel region. Paired t-test was used to compare the outcomes of peak pressure and maximum force with different two lifting postures and two object weights. Plantar peak pressure and maximum force under hallux was significantly greater in squat posture than stoop posture during the two different boxes lifting(p<.05). During the empty box lifting, maximum force under lessor toes was significantly less and plantar peak pressure under second metatarsal region was significantly greater in squat than stoop(p<.05). Maximum force under heel was significantly less in squat than stoop posture during 10kg box lifting(p<.05). Finally, COP trajectory path was significantly greater in squat than stoop(p<.05). These findings confirm that there are significantly change in the structure and function of the foot during the object lifting with different posture. Future studies should focus on the contribution of both structural and functional change to the development of common foot problems in adults.

• 한국운동역학회지
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• 제15권1호
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• pp.75-89
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• 2005

D. K. LEE, J. S. LEE, B. J. LEE, H. S. LEE, Y. J. KIM, S. B. PARK, J. P. JOO. Plantar foot pressure analysis during golf swing motion using plantar foot pressure measurement system. Korean Journal of Sport Biomechanics, Vol. 15, No. 1, pp. 75-89, 2005. In this study, weight carrying pattern analysis and comparison method of four foot region were suggested. We used three types of club(driver, iron7, pitching wedge). This analysis method can compare between top class golfer and beginner. And the comparison data can be used to correct the swing pose of trainee. If motion analysis system, which can measure the swing speed and instantaneous acceleration at the point of hitting a ball, is combined with this plantar foot force analysis method, new design development of golf shoes to increase comfort and ball flight distance will be available. 1. Address acting, forces concentrated in rare foot regions and lateral foot of right foot. Back swing top acting, relatively high force occurred in medial forefoot region of left foot and forefoot region of right foot. Impact acting, high force value observed in the lateral rarefoot region of left foot and medial forefoot region of right foot. Finish acting, force concentration observed on the lateral region and rarefoot region of left foot. 2. Forces were increased in address of right foot with clubs length increased. All clubs, back swing top acting, high force value observed in the lateral forefoot region of right foot. All clubs, in impact, high force value observed in the lateral rarefoot region of left foot and medial forefoot region of right foot. Finish acting, force concentration observed on the rarefoot region in driver and lateral foot region in iron on left foot. 3. Right foot forces distribution were increased in address, back swing top and left foot force distribution were increased in impact, finnish

• 한국운동역학회지
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• 제15권2호
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• pp.41-55
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• 2005

In this study, weight carrying pattern analysis and comparison method of four foot region were suggested. We used three types of club(driver, iron7, pitching wedge). This analysis method can compare between top class golfer and beginner. And the comparison data can be used to correct the swing pose of trainee. If motion analysis system, which can measure the swing speed and instantaneous acceleration at the point of hitting a ball, is combined with this plantar foot force analysis method, new design development of golf shoes to increase comfort and ball flight distance will be available. 1. Regional change of force acting, in address, is evenly distributed on both feet. In back swing top, 76% on right foot, 75% on left foot as impact, and 86% on left foot as finish. As regional force acting, in address, pros get high marks on rare and inside of right foot and rare and outside for amateurs. In back swing top, it is higher as fore and inside of left foot, pros as rare part of right foot and amateurs as forefoot. In impact, it is higher for pros and amateurs in outside and rare part of left foot and fore and inside of right foot. In finish, for both pros and amateurs, it is higher for outside and rare parts of left foot. 2. For each club, forces are evenly distributed on both feet in address. In back swing top, the shorter a club is, the higher impact on right foot and the higher finish distribution on left foot. For all the clubs used, in each region, pros get higher on rare and inside of right foot and as amateurs on rare and outside of left foot in address. In back swing top, for all clubs, pros get higher on rare and outside of right foot as fore and outside for amateurs. In impact acting, for all clubs, rare and outside of left foot get higher. In finish, force concentrates on rarefoot. 3. On both feet force, right foot forces of amateurs is higher than those of pros in back swing top. In impact and finish, pros get higher on left foot.

• 대한인간공학회지
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• 제11권2호
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• pp.23-33
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• 1992

The distribution of the pressure between the sole of a feet and a supporting surface can reveal the information about the structure and fonction of the foot and the posural control of the whole body. In particular, the measurement of the vertical contact forces between the plantar surface of the foot and the shoe insole is of great importance to reveal the loading distributio patterns incurred from a particular shoe midsole design. In order to investigate the plantar surface pressure distribution, an insole-type sensor with a piezoelectric material is developed and tested. The present paper describes a new method to completely reduce both the shear force and pyroelectric effects that are normally caused from piezoelectric materials.

• 한국산업보건학회지
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• 제17권2호
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• pp.131-143
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• 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.

• 한국운동역학회지
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• 제18권2호
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• pp.1-9
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• 2008

본 연구는 장애물을 넘는 동안 장애물의 높이 변화가 보행 시 족저압에 미치는 영향을 알아보기 위해 실시하였으며 이를 위해 족저 최고 족저압과 최대 힘, 압력 중심의 이동 경로를 중심으로 자료를 수집하여 분석하였다. 근골격계에 문제가 없는 열여섯 명의 건강한 젊은 성인이 이 연구에 참여하여 맨발로 각각 평지, 10cm, 20cm 그리고 30cm의 장애물을 넘는 동안 입각기 발의 족저 최고 족저압과 최대 힘, 압력중심 이동경로를 측정하였다. 측정은 Tekscan사의 Footmat system을 이용하였으며, 대상자의 발을 일곱 개의 영역(두 개의 발가락 영역, 세 개의 전족부 영역, 한 개의 중족부와 후족부 영역)으로 나누어 수집한 자료를 일원배치분산분석을 이용하여 분석하였다. 본 연구를 통해 높이가 다른 여러 가지 장애물을 넘을 때, 입각기 동안 족저의 영역별 최고 족저압과 최대 힘은 발가락부위에서 유의하게 증가하는 것을 알 수 있었고 후족부위에서는 감소하였다. 그리고 장애물의 높이가 높아질수록 압력중심 이동경로가 짧아지면서 전족부에서 외전하는 경향을 볼 수 있었다. 따라서 본 연구에서는 장애물 보행 시 장애물의 높이가 발의 구조와 기능에 영향을 미친다는 것을 확인할 수 있었다.

• 한국전문물리치료학회지
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• 제23권1호
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• pp.72-79
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• 2016

Background: Increased foot pronation causes biomedchanical changes at the lower limbs, which may result in musculoskeletal injuries at the proximal joints. Pronation rear-foot leads to plantar fasciitis, Achilles tendonitis, and posterior tibial tendonitis pathologically. According to the recent meta-analysis, They showed that therapeutic adhesive taping is more effective than foot orthoses and motion control footwear, low-Dye (LD) taping has become the most popular method used by physiotherapists. Objects: The purpose of this study was to determine the immediate effects of LD taping results in different ankle motion and ground reaction force (GRF) as before and after applied LD taping on pronated rear-foot during gait. Methods: Twenty-four participants were recruited for this study. The gait data were recorded using an 8-camera motion capture system and two force platforms. At first, the experiments were carried out that participants walked barefoot without LD taping. And then they walked both feet was applied LD taping. Results: The ankle inversion minimum was significantly greater after LD taping than before LD taping (p=.04); however, in the GRF, there were no significant differences in the inversion maximum or total motion of the stance phase (p=.33, p=.07), or in the vertical (p=.33), posterior (p=.22), and lateral (p=.14) peak forces. Conclusion: The application of taping to pronation rear-foot assists in increased ankle inversion.

• 한국운동역학회지
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• 제26권2호
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• pp.153-159
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• 2016

Objective: The purpose of this study was to investigate the effects of joint mobilization on foot pressure, ankle moment, and vertical ground reaction force in subjects with ankle instability. Method: Twenty male subjects (age, $25.38{\pm}3.62yr$; height, $170.92{\pm}5.41cm$; weight, $60.74{\pm}9.63kg$; body mass index (BMI), $19.20{\pm}1.67kg/m^2$) participated and underwent ankle joint mobilization. Weight-bearing distribution, ankle dorsi/plantar flexion moment, and vertical ground reaction force were measured using a GPS 400 and a VICON Motion System (Oxford, UK), and subsequently analyzed. SPSS 20.0 for Windows was used for data processing and paired t-tests were used to compare pre- and post-mobilization measurements. The significance level was set at ${\alpha}$ = .05. Results: The results indicated changes in weight-bearing, ankle dorsi/plantar flexion moment, and vertical ground reaction force. The findings showed changes in weight-bearing distribution on the left (pre $29.51{\pm}6.31kg$, post $29.57{\pm}5.02kg$) and right foot (pre $32.40{\pm}6.30kg$, post $31.18{\pm}5.47kg$). There were significant differences in dorsi/plantar flexion moment (p < .01), and there were significant increases in vertical ground reaction forces at initial stance (Fz1) and terminal stance (Fz2, p < .05). Additionally, there was a significant reduction in vertical ground reaction force at midstance (Fz2, p < .001). Conclusion: Joint mobilization appears to alter weight-bearing distribution in subjects with ankle instability, with resultant improvements in stability.

• 한국정밀공학회지
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• 제24권1호
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• pp.85-92
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• 2007

In the present study, three-dimensional motion analyses were performed to determine biomechanics of the lower extremity in unexpected missing foot steps for ten healthy young volunteers. In unexpected missing foot steps, the whole plantar surface of the foot or the heel contacted to the ground. A rapid ankle dorsiflexion was found right after missing foot steps and an increased plantarflexion moment was noted during loading response. After the unexpected situation, the breaking force increased rapidly. At this time, both tibialis anterior and soleus were simultaneously activated. Moreover, the range of motion at ankle, knee and hip significantly decreased during stance. In pre-swing, rectus femoris and biceps femoris prevented the collapse of the lower limbs. During late stance, propulsive forces decreased and thus, both plantarflexion moment and power generation were significantly reduced. On the opposite side, hip extension and pelvic upward motion during terminal swing were significant. Due to the shortened pre-swing, the energy generation at the ankle to push sufficiently off the ground was greatly reduced. This preliminary study would be helpful to understand the biomechanics of unexpected dynamic perturbations and valuable to prevent frequent falling of the elderly and patients with gait disorders.

• 한국운동역학회지
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• 제14권2호
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• pp.105-119
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• 2004

To enhance our understanding of the loads on the foot during treadmill running, we have used a pressure-sensitive insole system to determine pressure, rate of loading and impulse distributions on the plantar surface during treadmill running, both in minimally cushioned footwear and in cushioned shoes. This report includes pressure, rate of loading, impulse and contact time data from a study of ten subjects running on a treadmill at 4.0m/s. Among heel-toe runners, the highest peak pressures and highest rates of loading were observed under the centre of the heel and in the medial forefoot. The arch regions were only lightly loaded. Contact time was greater in the forefoot than in the heel. Two-thirds of the impulse recorded during the step was the result of forces applied through the forefoot, mostly in the region of the metatarsal heads. The distribution of loads in the shoe suggests that the load distributing properties of the cushioning system are most important in the centre of the heel, under the metatarsal heads and great toe. Shock attenuation is primarily required under the centre of the heel and to lesser extent under the metatarsal heads. Some energy dissipation may be desirable in the heel region because it causes shock to be absorbed with less force. All the 'propulsive' effort is applied through the forefoot. Therefore, this region should as resilient as possible.