• Korean Journal of Applied Biomechanics
• /
• v.20 no.2
• /
• pp.167-174
• /
• 2010

This study aims to quantitatively compare and analyze kinetic variables in the motion of male and female professional golfers to suggest basic scientific materials for golf iron swing. Five male and five female professional golfers participated in this experiment. Ground reaction force and foot pressure were measured during performing 10 swings for each participants using an iron club. The result of the ground reaction force indicates that the force occurs at the left foot toward right(-) direction in the mid-downswing(E3) and impact(E4) events in X-axis, while it occurs at the right foot toward anterior(-) direction in Y-axis for both male and female, showing a big difference between them. Also, in Z-axis, large force occurs at the left foot in most events. The analyzed result on foot pressure indicates that men have the highest pressure and area at the left foot, and women have the highest ones at the right foot in the mid-downswing(E3) and impact(E4) events in the max foot pressure, ground contact area and average pressure. It is considered that there is difference of central movement methods between men and women. Thus, different education and training on golf swing should be necessary by gender due to their different patterns of golf iron swing.

• Journal of the Korean Society of Physical Medicine
• /
• v.5 no.1
• /
• pp.43-51
• /
• 2010

Purpose : The purpose of this study was to compare plantar pressure distribution between affected side and unaffected side and to analyze plantar pressure distribution of affected side according to the extent of hemineglect in the adult hemiplegia. Methods : Twenty-five hemiplegia participated in this study. The analysis of plantar pressure distribution was conducted by the F-scan system, and the extent of hemineglect was evaluated with line-bisection test. While the subject walked about 10 meters in their comfortable speed the plantar pressure was evaluated and stored. Results : Total contact area, AP CoP trajectory, contact pressure of mid-foot of the affected side were significantly different from the unaffected side. Total contact area, AP CoP trajectory and contact pressure of mid-foot were smaller than those of unaffected side. In the comparison among the group according to the extent of hemineglect, AP CoP trajectory of subject who has severe hemineglect was significantly different from the patient that has no hemineglect and it was shorter than that of no hemineglect. Conclusion : The plantar pressure distribution was generally different between affected side and unaffected side and the hemineglect affected negatively the patient to move CoP forwardly while walking. Accordingly, it will help the clinician to understand the hemineglect which has an effect on abnormal walking and to intervent the hemiplegia who has a neglection to the affected side.

• The Journal of the Korea Contents Association
• /
• v.10 no.2
• /
• pp.268-276
• /
• 2010

This study was to investigate the knee joint flexion angle and the foot pressure during climbing with different slope. The 24 healthy subjects were participated. And foot pressure was investigated using Parotec system. The knee joint flexion angle were filmed to using a video camera on each slope($0^{\circ},\;3^{\circ},\;6{\circ},\;9^{\circ}$). And knee joint angle was investigated by Dartfish. The data were analyzed ANOVAs. In conclusion, there was significantly different that knee joint flexion angle related on each slope angle. In foot pressure, there was significantly different in lateral heel area(1 cell), medial midfoot area(9 cell), medial forefoot area(15, 16 cell) of left foot, and in lateral heel area(3 cell) of right foot. There was significantly different of foot pressure in lateral and medial heel when knee joint flexion angle is between $10^{\circ}$ and $20^{\circ}$. There was change of gait cycle according to walking slop angle increasing, and the initial contact phase was shorter, the foot pressure in lateral heel was lower.

• Journal of Korean Foot and Ankle Society
• /
• v.10 no.2
• /
• pp.125-132
• /
• 2006

Purpose: The purpose of this study was to evaluate pressure distribution on the foot with the use of custom made foot orthosis and evaluate influential factors in young people using custom orthosis. Materials and Methods: 22 individuals comprised of young males and females were evaluated by radiograph, pedobarograph, and satisfaction rate and VAS score. The data was analyzed statistically to find influential factors for satisfaction after wearing the foot orthosis. Results: Around 50% of participants were satisfied in wearing the custom made foot orthosis. Initial VAS score of satisfaction of $36.2{\pm}19.7$ improved to $73.1{\pm}15.6$ after application of foot orthosis. There was a statistically significant difference. Talo-second metatarsal angle on AP radiograph after orthosis application was significantly related to satisfaction. On analysis of pedobarograph data, total contact area was increased and weight distribution was transferred medially on ambulation with the orthosis applied. Conclusion: Before designing the foot orthosis, individual foot factors such as foot anatomy and foot pressure distribution should be evaluated for foot comfort and better patient satisfaction.

• Korean Journal of Applied Biomechanics
• /
• v.20 no.3
• /
• pp.345-353
• /
• 2010

The purpose of this study was to compare and biomechanical evaluate the effects of three varying functional insoles on the kinematics of the lower extremities and foot pressure distribution during gait. For this 12 subjects participated in this study and each worn the 3 functional insoles during gait which kinematics, kinetics, electromyography and foot pressures were recorded. The function on the first insole was to absorb shock and increase the dynamic stability, the second was a gel type to absorb shock, and the third was to massage the center regions of the foot sole. the results were as follows; the first insole reduced the joints range of motion and reduced muscular fatigue, the second insole reduce the maximum, total and average foot pressures. Finally, the third insole produced larger values for the contact times and contact area.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.36 no.8
• /
• pp.913-920
• /
• 2012

An efficient 3D finite element walking model that considers the detailed shapes of muscles, ligaments, bones, skin, and soles was developed based on a real computed tomography (CT) scan image of a foot, and nonlinear contact analyses were performed to investigate pressure changes. The highest pressure occurs at the rear bottom of the foot when standing and walking. The pressure on the outsole with a curved foot bottom surface is lessened and distributed over a wider area than in the case of a flat outsole. The result shows that a shoe sole shape optimized for diabetes patients can relieve the foot pressure concentration and prevent further worsening of symptoms.

• The Journal of Korean Physical Therapy
• /
• v.23 no.6
• /
• pp.15-22
• /
• 2011

Purpose: This research investigated falls due to obstacles that occur among elderly people by assessing changes in the values of plantar foot force, peak force, and plantar foot pressure in elderly subjects while they were stepping over obstacles of different heights. Methods: The subjects were 20 elderly people aged 70-80 years; Pressure was measured on flat ground(0 cm), and after installing obstacles of 8 cm and 12 cm using the F-scan system, which is a resistance-type pressure sensor. A one-way analysis of variance was performed to compare pressure on each part of the foot according to various heights after collecting data using the Tekscan program. The least significant difference test was used for the post-hoc analysis, A p-value <0.05 was considered significant. Results: The force value for the toe area (parts 1, and 2) and contact pressure increased significantly with the 12 cm obstacle (p<0.05). The peak force value and the peak contact pressure for part 1 increased significantly with the 12 cm obstacle (p<0.05). Conclusion: Larger changes appeared in the functions and structure of the foot while subjects walked over obstacles of different heights compared to flatland walking. This result suggests that people have safety strategies to prevent falls, and that there is a need for a more realistic approach through practice to overcome obstacles of various heights to prevent falls.

• Physical Therapy Korea
• /
• v.20 no.4
• /
• 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.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 1999.10a
• /
• pp.525-529
• /
• 1999

A cone shape drum polisher was developed to make up for the demerits of conventional CMP apparatus. The developed equipment has several superiorities. First of all, it can achieve uniform velocity profile on all the contact line because of its shape and easy to control the amount of slurry at the position of use. The whole area of wafer surface is exposed to the visual area except the contact line between wafer and drum, hence we can detect polishing end point more easily than any other polishing equipments. Also it has additional merits such as small foot print and polishing load. Polishing characteristics were investigated by developed equipment.

• Korean Journal of Applied Biomechanics
• /
• v.22 no.1
• /
• pp.113-121
• /
• 2012

The purpose of this study was to evaluate the effects of forefoot rocker shoes equipped with a metatarsal bar on lower extremity muscle activity and plantar pressure distribution. Ten healthy women in the age of twenties were participated in this study as the subjects. All subjects walked on a treadmill(Gait Trainer, BIODEX, USA) wearing normal shoes and metatarsal bar shoes, during which the plantar pressure distribution and muscle activity were measured. Using Pedar-X system(Novel Gmbh, Germany), the plantar pressure was measured for six regions of the foot: forefoot, midfoot, rearfoot, 1st metatarsal, 2-3th metatarsal, and 4-5th metatarsal, and for each sub-region, 4 features such as maximum force, contact area, peak pressure, and mean pressure were analyzed based on the plantar pressure. EMG(Electromyography) activity was measured by attaching surface electrodes to the rectus femoris, biceps femoris, tibialis anterior, and gastrocnemius medial head, and magnitude of muscle contraction was analyzed in IEMG(Integrated EMG) value. The results show that the maximum force, contact area, peak pressure, and mean pressure in the midfoot all increased while maximum force, peak pressure, contact area, mean pressure in the 1st metatarsal and 2-3th metatarsal all decreased when wearing functional shoes. Also, muscle activities in the four muscles were all decreased when wearing the functional shoes. This paper suggests that forfoot rocker shoes equipped with a metatarsal bar can help disperse the high pressure and absorb the shock to the foot as well as give positive influence on gait pattern and postural stability by reducing muscle fatigue during walking.