• Korean Journal of Applied Biomechanics
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• v.20 no.1
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• pp.13-23
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• 2010

The purposes of this study was to investigate the biomechanical influence of the walking shoe with a plate spring in the heel and interchangeable heel cushioning elements. Eighteen subjects walked in three conditions: 1) the walking shoes Type A-1 with a soft heel insert, 2) the Type A-2 shoe with a stiff heel insert, 3) a general walking shoe(Type B). Ground reaction forces, leg movements, leg muscle activity and ankle, knee and hip joint loading were measured and calculated during overground walking. During walking, the ankle is a few degrees more dorsiflexed during landing and the knee is slightly more flexed during takeoff with the Type A shoes. As a result of the changes in the walking movement, the ground reaction forces are applied more quickly and the peak magnitudes are higher. Muscle activity of the quadricep, hamstring and calf muscles decrease during the first 25% of the stance phase when walking in the Type A shoes. The resultant joint moments at the ankle, knee and hip joints decrease from 30-40% with the largest reductions occurring during landing.

• Korean Journal of Applied Biomechanics
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• v.19 no.1
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• pp.13-25
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• 2009

Existing footwear biomechanics studies rely on simplified kinetics and kinematics, plantar pressure and muscle electromyography measurements. Because of the complexity of foot-shoe interface and individualized subject response with different footwear, consistent results regarding the biomechanical performance of footwear or footwear components can yet be achieved. The computational approach can be an efficient and economic alternative to study the biomechanical interactions of foot and footwear. Continuous advancement in numerical techniques as well as computer technology has made the finite element method a versatile and successful tool for biomechanics researchdue to its capability of modelling irregular geometrical structures, complex material properties, and complicated loading and boundary conditions. Finite element analysis offers asystematic and economic alternative in search of more in-depth biomechanical information such as the internal stress and strain distributions of foot and footwear structures. In this paper, the current establishments and applications of the computational approach for footwear design and evaluation are reviewed.

• Physical Therapy Korea
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• v.15 no.1
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• pp.38-45
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• 2008

This study investigated gait characteristics, kinematics, and kinetics in the lower extremities between two different shoe conditions (high heeled shoes (7 cm), and high heeled shoes with a total contact insert (TCI)) after lower extremity muscle fatigue. Although TCI shave been applied in high heeled shoes to increase comfort and to decrease foot pressure, no study has attempted to identify the effects of TCI in fatigue conditions. The purpose of this study was to determine the effects of walking in high heeled shoes with TCI after lower extremity muscle fatigue was induced. This study was carried out in a motion analysis laboratory at Hanseo University. A volunteer sample of 14 healthy female subjects participated. All in fatigue conditions, the subjects were divided into two groups. The muscle fatigue was induced by 40 voluntary dorsi- and plantar-flexion exercises and 40 heel-rise exercises of the dominant foot. Surface electromyography was used to confirm the localized muscle fatigue using power spectral analysis of three muscles (tibialis anterior, gastrocnemius medialis and lateralis). The results were as follows: (1) In muscle fatigue conditions, the use of TCI decreased the peak flexion angle of the hip joint significantly in the early stance phase (p<.05) and increased the peak hip flexion moment in the terminal stance phase (p<.05). (2) In muscle fatigue conditions, the application of TCI also increased peak hip power generation in the early stance phase and peak hip power absorption in the terminal stance phase (p<.05). (3) In muscle fatigue conditions, the use of TCI reduced the impact force significantly and increased the secondary peak vertical GRF. These findings suggest that the TCI may provide beneficial effects when muscle fatigue occurs for a high heeled shoe gait. Future research employing the patient population and various types of TCI materials are required to clarify the effects of TCI.

• PNF and Movement
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• v.18 no.2
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• pp.215-222
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• 2020

Purpose: The study investigated the effect on chronic stroke patients' balance of a weight shift to the affected side using an insole on the less affected side during treadmill walking training. Methods: The subjects were 7 patients who had been diagnosed with stroke 6-24 months prior to the study. In each case, an insole was applied on the patient's less affected side during treadmill walking training. Each training session lasted 30 minutes and was undertaken 5 times per week for 4 weeks. Biorescue equipment that measures shifts in center of pressure was used to assess balance ability as measured by the Korea-Berg balance scale (K-BBS) before and after each training intervention. The Wilcoxon signed-rank test was used to evaluate within-group effects. Results: The results revealed statistically significant before and after differences in area, pressure, length, and mean velocity of the balance test and on K-BBS (p < 0.05). Conclusion: In chronic stroke patients, using an insole to adjust the height of the shoe on the less affected side is an effective means of increasing weight-shifting on the paralyzed side during treadmill gait training.

• Korean Journal of Applied Biomechanics
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• v.17 no.3
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• pp.81-94
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• 2007

The purpose of this study was to critically review biomechanical studies on foot orthoses (FO) in normal and diseased foot and provide beneficial information obtained from researches until now and future researching focus. The search was performed by Medline and Embase database including studies published in English from January 1980 to April 2007. The searching terms were foot orthoses, foot orthotics, insoles and shoe insert. 57 studies including 54 journal articles and 3 abstracts were finally selected under the conditions of having clinical trials, FO, control condition, movement, scientific measuring system. The reviewed studies were divided into 10 categories according to subject characteristics; healthy normal, excessive pronation or flexible flat foot, rheumatoid arthritis, diabetes, medial knee osteoarthritis, forefoot varus, plantar fasciitis, patellofemoral syndrome, cavus foot and finite element model. In summary, first, soft and semirigid FOs with some degree of cushioning showed much higher comfort and efficacy than rigid FO. Second, no big differences between prefabricated and custom FO were shown. Third, the full length's FO was preferable to the half length's FO or simple arch supports. Fourth, the wearing of FO combining medial arch supports and metatarsal dome made positive roles to enhance comfort and functionality and redistribute plantar pressure under the foot. Fifth, for patients with knee-related diseases lateral wedges were preferable. Sixth, measuring systems were properly applied according to the types of foot diseases.