• Physical Therapy Korea
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• v.30 no.4
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• pp.281-287
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• 2023

Background: The flexible flatfoot is characterized by a flattening of the foot arch due to excessive bodyweight. The use of shoe insoles or taping methods has been identified as effective in realigning the navicular or calcaneus bones and addressing supination in pronated feet. Objects: This study aimed to analyze the difference between the arch taping attachment method, introduced in a previous study, and a novel taping method designed to provide support to the inner aspect of the heel bone in cases of flexible flatfoot. Methods: A navicular drop test was performed to discriminate flexible flatfoot. To analyze the differences in pressure distribution during walking for each taping method, the subjects underwent testing in the barefoot state with no attachments. The procedure included a sequence of arch taping and heel taping. Subsequent analysis of pressure distribution during walking utilized the GaitRite^® system (GAITRite Gold, CIR Systems Inc.). Results: Arch taping and calcaneus taping significantly reduced the integrated pressure over time and peak pressure on the medial side of the midfoot for both feet compared to the barefoot state. Conclusion: The findings of this study suggest that supporting the inside of the heel through calcaneus taping, without direct stimulation to the longitudinal arch and navicular bone, is an effective intervention for flexible flatfoot.

• Physical Therapy Korea
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• v.27 no.2
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• pp.126-132
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• 2020

Background: Augmented somatosensory feedback stimulates the mechanoreceptor to deliver information on bodily position, improving the postural control. The various types of such feedback include ankle-foot orthoses (AFOs) and vibration. The optimal feedback to mitigate postural sway remains unclear, as does the effect of augmented somatosensory feedback on muscle co-contraction. Objects: We compared postural sway and ankle muscle co-contraction without feedback (control) and with either of two forms of somatosensory feedback (AFOs and vibration). Methods: We recruited 15 healthy subjects and tested them under three feedback conditions (control, AFOs, vibration) with two sensory conditions (eyes open, or eyes closed and the head tilted back), in random order. Postural sway was measured using a force platform; the mean sway area of the 95% confidence ellipse (AREA) and the mean velocity of the center-of-pressure displacement (VEL) were assessed. Co-contraction of the tibialis anterior and gastrocnemius muscles was measured using electromyography and converted into a co-contraction index (CI). Results: We found significant main effects of the three feedback states on postural sway (AREA, VEL) and the CI. The two sensory conditions exerted significant main effects on postural sway (AREA and VEL). AFOs reduced postural sway to a level significantly lower than that of the control (p = 0.014, p < 0.001) or that afforded by vibration (p = 0.024, p < 0.001). In terms of CI amelioration, the AFOs condition was significantly better than the control (p = 0.004). Vibration did not significantly improve either postural sway or the CI compared to the control condition. There was no significant interaction effect between the three feedback conditions and the two sensory conditions. Conclusion: Lower-extremity devices such as AFOs enhance somatosensory perception, improving postural control and decreasing the CI during static standing.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.10a
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• pp.24-24
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• 2003

For the elderly, achieving a close-to-normal ambulation is important for activities of daily life. Recent researches of SE(Silver Engineering) restoring physical ability would help the elderly by developing the advanced gait assisting devices and orthoses. For the applications using the advanced technologies, the gait characteristics of the elderly must be understood. However, a few studies were performed to investigate the physiological or pathological gaits. The purpose of this study is to provide the gait analysis data and also to investigate relationships between alignment of the lower limb, foot progression angle and knee joint moments in the healthy elderly. By participating a total of 20 healthy elderly persons in this study, the following facts were found: 1) Cadence showed 114.8 steps/min, gait speed showed 1.05 m/s, time per a stride showed 1.06 sec, time per a step showed 0.53 sec, single-supporting phase was 0.41 sec, double-supporting phase was 0.24 sec, stride length was 1.04m, Step length was 0.56m; 2) The maximum knee flexion angle through swing phase showed left 46.82$^{\circ}$, right 40.19$^{\circ}$ and the maximum knee extension angle showed left -1.32$^{\circ}$, right 2.01$^{\circ}$. Knee varus showed left 26.90$^{\circ}$, right 30.93$^{\circ}$; 3) The maximum knee flexion moment showed left 0.363 Nm/kg, right 0.464 Nm/kg, The maximum knee extension moment showed left 0.389 Nm/kg, right 0.463 Nm/kg. The maximum knee adduction moment showed left 0.332 Nm/kg, right 0.379 Nm/kg. The maximum internal rotational moment showed left 0.13 Nm/kg, right 0.140 Nm/kg; 4) The subjects who had varus alignment of the lower extremity had statistically higher in knee adduction moment in mid stance phase; and 5) The subjects who had large foot progression angle had statistically lower in knee adduction moment in late stance phase.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.8 no.4
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• pp.291-297
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• 2014

The purpose of this study was to investigate the change of the electromyographic activity in vastus medialis oblique (VMO) and vastus lateralis (VL), also vastus medialis oblique/vastus lateralis ratios after wearing wedged flated or 5cm heel shoes. The subjects were 30 healthy women who randomly assigned to two group, divided by flated or 5cm heel group. They were asked to perform squat exercise in two postures using medial and lateral wedged shoes. In two groups, EMG activity of VMO and VL was significant difference between the flated heel and 5cm heel (p<.01). This study showed that 5cm heel could selectively more active VMO than flated heel. It should be considered the heel height as the parameter when the patient with lower extremity problem undergo rehabilitation exercise or design of orthoses for the selective muscle activity of knee pain or knee instability.

• Journal of the Korean Society of Physical Medicine
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• v.11 no.4
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• pp.11-17
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• 2016

PURPOSE: There are several standard interventions for managing Achilles tendinitis, including eccentric exercise and calf muscle stretches, orthoses, electrotherapy, and taping. However, no study has determined the effect of non-elastic taping on deloading the Achilles tendon while vertical jumping. Therefore, this study determined the effect of non-elastic taping on ankle dorsiflexion and the triceps surae muscle activity while vertical jumping in healthy subjects. METHODS: The study recruited 17 participants. A motion analysis system was used to measure the angle of ankle dorsiflexion and wireless surface electromyography was used to measure the soleus and gastrocnemius activities while vertical jumping. Non-elastic taping was applied on randomized leg side. All subjects performed maximal effort vertical jumps without and with non-elastic taping, with three trials for each condition. The mean peak dorsiflexion and muscle activities during the three trials were calculated and paired t-tests were used to compare the mean values without and with non-elastic taping. Significance was defined as (p<.05). RESULTS: The maximum angle of ankle dorsiflexion and activity of the gastrocnemius muscle decreased significantly when non-elastic tape was applied (p<.05), while there was no significant difference in the soleus activity between no-taping and taping (p>.05). CONCLUSION: We introduce non-elastic taping as a method to decrease maximum ankle dorsiflexion and gastrocnemius activity while vertical jumping.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.11 no.1
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• pp.65-73
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• 2005

Osteoarthritis has been considered a disease of the elderly because it is uncommon before the age of 40 years and is seen in approximately 80% of United States citizens older than 65 years. general population on kuri city in korea revealed that prevalence of knee osteoarthritis is 10.2%, increasing with age. High level of physical activity in men and age, post-menopause and obesity in women can be risk factor. Osteoarthritis is no evidence that a acquired process initiated much earlier in life through mechanical, metabolic, genetic, or other origins. A high tibial osteotomy alters static lower extremity alignment thereby decreasing medial compartment loading. As well, conservative treatment strategies, such as knee braces and valgus heel wedges, affect lover limb mechanics and attempt to reduce medial compartment loading. It was hypothesized that valgus heel wedges and modified orthoses would shift the center of pressure laterally on the foot during level walking, reducing the moment arm of the adduction moment in the frontal plane, thereby resulting in a decrease in the knee adduction moment. In the 1980s, the effect of wearing a laterally wedged insole on osteoarthritic patients with a varus deformity of the knee was firsted, and since then, kinematic and kinetic analyses concerning this condition have mainly focused on a static standing position. Since the early 1990s, the beneficial effect of wearing a laterally wedged insole to treat osteoarthritis of the knee has also been reported in dynamic conditions, but these studies did not answer the question of the kinematic and kinetic mechanisms that resulted in the reduced symptoms in patents with knee osteoarthritis. therefore, the effect of wearing laterally wedged insole has not been sufficiently studied.

• Journal of Korean Foot and Ankle Society
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• v.24 no.3
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• pp.113-119
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• 2020

Purpose: A flatfoot that fails to form a longitudinal foot arch is a common lower limb deformity in children. This study evaluated the structural and functional effects of the insole for pediatric flexible flat foot (PFFF). Materials and Methods: Twenty-nine PFFF patients (20 boys and 9 girls, 58 feet) with bilateral symptomatic flatfoot deformities between February 2017 and May 2019 were included in this study. Sixteen patients (32 cases, study group) were treated with a pressured based 3-dimensional printing insole, and 13 patients (26 cases, control group) were followed up regularly without any treatment. Flatfoot was diagnosed by a lateral talo-first metatarsal angle of more than 4° in convex downward and talocalcaneal angles of more than 30° and a calcaneal pitch of less than 20°. The foot pressures, including the midfoot pressure, total foot pressure, and the ratio of the midfoot pressure to the total foot pressure, were evaluated by pedobarography. The clinical scores were assessed using the visual analogue scale (VAS), American Orthopaedic Foot and Ankle Society (AOFAS), and Pediatrics Outcomes Data Collection Instrument (PODCI) scores. Results: The mean age of the study group was 9.16 years, and the mean age of the control group was 7.73 years. The mean follow-up period was 16 months. The change in the lateral talocalcaneal angle was -4.664°±1.239° in the study group and -0.484°±1.513° in the control group. A significant difference in the amount of change of the lateral talocalcaneal angle was observed between the two groups (p=0.034). The midfoot pressures were similar in the two groups. Conclusion: Pressure based customized 3-dimensional printing insole in PFFF may have some effect on the hindfoot bony alignment, but it does not affect the changes in midfoot pressure.

• Physical Therapy Rehabilitation Science
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• v.7 no.1
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• pp.23-28
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• 2018

Objective: The purpose of this study was to investigate the impact of wearing various types of shoes on gait ability in stroke survivors and in order to gain information in regards to shoes that could possibly replace ankle orthosis. Design: Cross-sectional study. Methods: Eight hemiplegic survivors diagnosed with stroke participated in the study. Gait was analyzed using the GAITRite Electronic Walkway (CIR System Inc., USA) when subjects walked with no showed, walked with non-ankle-covered shoes, and walked with ankle-covered shoes. This study collected gait variables, including velocity, cadence, step length, stride length, single support time, and double support time, respectively. Results: In the comparison of walking with no shoes, non-ankle-covered shoes, and ankle-covered shoes, there were significant differences in gait velocity, step length, stride length, and the less affected side single support time (p<0.05). However, there were no significant differences in cadence, affected side single support time, and double support time. Conclusions: Ankle-covered shoes had a positive impact on the gait of stroke survivors. However, it is necessary to conduct more studies comparing various types of shoes with ankle orthoses.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.6 s.171
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• pp.213-221
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• 2005

An insole type local shear force measurement system was developed and local shear stresses in the foot were measured during level walking. The shear force transducer based on the magneto-resistive principle, was a rigid 3-layer circular disc. Sensor calibrations with a specially designed calibration device showed that it provided relatively linear sensor outputs. Shear transducers were mounted on the locations of four metatarsal heads and heel in the insole. Sensor outputs were amplified, decorded in the bluetooth transmission part and then transferred to PC. In order to evaluate the developed system, both shear and plantar pressure measurements, synchronized with the three-dimensional motion analysis system, were performed on twelve young healthy male subjects, walking at their comfortable speeds. The maximum peak pressure during gait was 5.00kPa/B.W at the heel. The time when large local shear stresses were acted correlated well with the time of fast COP movements. The anteroposterior shear was dominant near the COP trajectory, but the mediolateral shear was noted away from the COP trajectory. The vector sum of shear stresses revealed a strong correlation with COP movement velocity. The present study will be helpful to select the material and to design of foot orthoses and orthopedic shoes for diabetic neuropathy or Hansen disease.

• Journal of Biomedical Engineering Research
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• v.24 no.6 s.81
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• pp.501-507
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• 2003

Medical devices for helping the rehabilitation of the patients such as orthoses and prostheses should be designed to be strong enough. For the strength design, operational load should be identified first. Furthermore. medical devices are susceptible to dynamic load or shock frequently due to its characteristics. These type of the load may be identified by installing the sensors directly. However, it can modify the natural properties of the structures. Therefore, operational load should be identified indirectly from the system characteristics and responses such as vibrations. In this paper, the basic formulation of the indirect load identification is reviewed and the problems of conventional approach are checked. Then, the new approach based upon the principal component analysis is proposed and the validity of the proposed method is demonstrated using experiments.