• Korean Journal of Applied Biomechanics
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• v.25 no.3
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• pp.323-333
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• 2015

Objective : The purpose of this study was to investigate the changes of gait patterns and muscle activations with increased loads during stair walking. Also, it can be used as descriptive data about continuous stair walking in a real life setting. Method : Twelve sedentary young male adults(Age: $27.0{\pm}1.8yrs$, Weight: $65.8{\pm}9.9kg$) without any lower extremity injuries participated in this study. Participants performed stair walking up 7 floors and their ascending and descending motion on each floor was analyzed. A wireless electromyography(EMG) were attached on the Rectus Femoris(RF), Biceps Femoris(BF), Gastrocnemius(GN), Tibialis Anterior(TA) muscle to calculate integrated EMG(iEMG), median frequency(MDF) and co-contraction index(CI). Chest and left heel accelerometer signal were recorded by wireless accelerometer and those were used to calculate approximate entropy(ApEn) for analyzing gait pattern. All analyses were performed with SPSS 21.0 and for repeated measured ANOVA and Post-hoc was LSD. Results : During ascending stairs, there were a statistically significant difference in Walking time between 1-2nd and other floors(p=.000), GN iEMG between 2-3th and 6-7th(p=.043) floor, TA MDF between 1-2nd and 5-6th(p=.030), 6-7th(p=.015) floor and TA/GN CI between 2-3th and 6-7th(p=.038) floor and ApEn between 1-2nd and 6-7th(x: p=.003, y: p=.005, z: p=.006) floor. During descending stairs, there were a statistically significant difference in TA iEMG between the 6-5th and 3-2nd(p=.026) floor, and for the ApEn between the 1-2nd and 6-7th(x: p=.037, y: p=.000, z: p=.000) floor. Conclusion : Subjects showed more regular pattern and muscle activation response caused by regularity during ascending stairs. Regularity during the first part of stair-descending could be a sign of adaptation; however, complexity during the second part could be a strategy to decrease the impact.

• Korean Journal of Applied Biomechanics
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• v.19 no.2
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• pp.287-296
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• 2009

This is written to present basic shot information among iron clubs and information of weight shift, because previous study conducted on all clubs was rut enough. This article is about shot analysis of iron club 3,4,5,6,7,8,9 and weight movement, conducted on four skilled golf players and four students who major in golf and are less than three years. The analysis of long and short irons showed statistically meaningful different results for all the participants but iron clubs of 3,4,5 didn't in head speed and ball speed. The skilled group showed better results in head speed, ball speed and direction, Launch angle than the unskilled group. In weight shift movement analysis, the unskilled group moved, on back swing top, their more weight(65.36%) but the skilled group was on their left foot (70.21%)when clubs were on impact moment. It shows that the skilled group put on power more efficiently by moving weight.

• The Research Journal of the Costume Culture
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• v.28 no.6
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• pp.771-786
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• 2020

This study aims to develop a life-friendly, wrap-one-piece style dance sports practice wear considering the physical characteristics of middle-aged, abdominally obese women. These types of practice wear allow people to enjoy exercise easily and to wear these garments as daily wear while meeting the requirements for dance sports wear. The three participants selected for this study were all women with five or more years of dance sports experience and were all average sized on Korea's abdominal obesity scale. In the first phase of the study, practice wear was created in a total of nine styles with three different styles of neckline depths for three different styles of dress skirt lengths. In the second phase of the study, the practice wear was created in 15 styles with five different styles of sleeve lengths for three different styles of waistline heights. After analyzing the design preferences of the participants, the fit preferences of the designs were evaluated and the final appearance was analyzed in order to suggest a pattern. The results of the subjects' first and second preference evaluations showed a preference for a 10 centimeter neckline depth, for high waistlines, and for elbow to wrist-length sleeves. The implementation of this research is expected to be extensive, as its results can be used as basic data for making lifestyle dance sports practice wear that covers the physical insecurities of middle-aged, abdominally obese women and enables them to enjoy their leisure time.

• Korean Journal of Applied Biomechanics
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• v.33 no.1
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• pp.25-33
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• 2023

Objective: The purpose of this study was to investigate the differences in static arch height and ankle stability according to the preference for insole height and hardness in the arch area. Method: The study participants were 20 adult males (age: 22.7 ± 1.8 yrs., height: 175.3 ± 4.3 cm, body weight: 72.5 ± 7.7 kg). First, the arch heights of all subjects were measured in static postures (sitting and standing). The inversion and eversion movements of the ankle joint were analyzed during walking (1.3 m/s & 1.7 m/s) and running (2.7 m/s & 3.3 m/s). The variables (static arch height, and inversion and eversion angle of ankle joint) were compared by classifying groups according to the preference for the height and hardness of the arch of the insole. First, it was divided into a high arch insole preference group (HAG, n=8) and a low arch insole preference group (LAG, n=12) according to the preference for the arch height of the insole. Second, it was divided into a high hardness insole preference group (HHG, n=7), medium hardness insole preference group (MHG, n=7), and low hardness insole preference group (LHG, n=6), according to the preference for the arch hardness of the insole. Results: First, the range of motion (ROM) of inversion-eversion at the ankle joint during walking was statistically smaller in HAG than in LAG (p<.05). Second, the arch height change of HHG was statistically greater than that of MHG and LHG (p<.05). Conclusion: In the case of flexible flat feet with a large change in arch height, providing a high hardness arch insole that can disperse foot pressure can improve comfort. It was found that people with high medial and lateral sway of the ankle joint preferred a low arch insole, but it is necessary to differentiate and compare the insole heights of the arch part in detail. In addition, in the case of fast motion such as running, the preference for the arch height and hardness of the insole was not related to the static arch height and ankle stability.

• Dementia and Neurocognitive Disorders
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• v.21 no.3
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• pp.93-102
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• 2022

Background and Purpose: The effects of high-intensity interval training (HIIT) interventions on functional brain changes in older adults remain unclear. This preliminary study aimed to explore the effect of physical exercise intervention (PEI), including HIIT, on cognitive function, physical performance, and electroencephalogram patterns in Korean elderly people. Methods: We enrolled six non-dementia participants aged >65 years from a community health center. PEI was conducted at the community health center for 4 weeks, three times/week, and 50 min/day. PEI, including HIIT, involved aerobic exercise, resistance training (muscle strength), flexibility, and balance. Wilcoxon signed rank test was used for data analysis. Results: After the PEI, there was improvement in the 30-second sit-to-stand test result (16.2±7.0 times vs. 24.8±5.5 times, p=0.027), 2-minute stationary march result (98.3±27.2 times vs. 143.7±36.9 times, p=0.027), T-wall response time (104.2±55.8 seconds vs.71.0±19.4 seconds, p=0.028), memory score (89.6±21.6 vs. 111.0±19.1, p=0.028), executive function score (33.3±5.3 vs. 37.0±5.1, p=0.046), and total Literacy Independent Cognitive Assessment score (214.6±30.6 vs. 241.6±22.8, p=0.028). Electroencephalography demonstrated that the beta power in the frontal region was increased, while the theta power in the temporal region was decreased (all p<0.05). Conclusions: Our HIIT PEI program effectively improved cognitive function, physical fitness, and electroencephalographic markers in elderly individuals; thus, it could be beneficial for improving functional brain activity in this population.

• Physical Therapy Rehabilitation Science
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• v.9 no.1
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• pp.18-24
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• 2020

Objective: The purpose of this study was to compare the activities of the abdominal muscles according to trunk stabilization exercises using Swiss ball in normal individuals. Design: Cross-sectional study. Methods: Ten healthy university students participated in this study. The subjects were required to complete the following three exercise positions: Exercise position 1, sitting on a Swiss ball and lifting the legs; Exercise position 2, pushing to a plank position from an ending position; and Exercise position 3, push-up posture with the legs on a Swiss ball. Changes in the trunk muscle activities were estimated using Biometric electromyography (EMG). Activities of the dominant side internal oblique muscle (IOM) and external oblique muscle (EOM) were estimated in all participants. The maximal voluntary isometric contraction (MVIC %) was measured to standardize the EMG signals for the IOM and EOM during maximum resistance when sitting up with each shoulder pointing towards the contralateral pelvis with knees bent and both arms crossed on the chest for 5 seconds. Results: There was a significant difference in the activity of the internal and external oblique muscles between Exercises 1 and 2 and Exercises 1 and 3 (p<0.05). Furthermore, the IOM/EOM activity ratio was the greatest during Exercise 3 and the smallest during Exercise 1. IOM and EOM activities were the greatest during Exercise 2 with greater EOM activity. Conclusions: In future studies, it will be necessary to investigate muscle activities by supplementing the above-mentioned limitations during the stabilization exercise. The results of this study may be used as a basis for controlling the intensity and frequency of exercise while prescribing trunk stabilization exercises.

• Journal of Korean Society of Rural Planning
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• v.28 no.2
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• pp.33-40
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• 2022

The purpose of this study is to review the effect of previous research data with virtual reality-based Physical Activity Therapy Programs(PATPs) in adult on the physical fitness factors. Research articles were retrieved from 2008 to 2021 with the Research Information Sharing Service(RISS) and Pubmed database. The main search terms were 'care', 'therapy', 'healing', 'exercise' or 'physical activity', and 'virtual reality'. The criteria for selecting articles of this study were the originality, duplication, Randomized controlled trial(RCT) experiment and subject. Finally, 18 papers were selected among 318 articles, which were excluded if any of the criteria was not satisfied. Most of papers(15) were conducted in the last 5 years, because of the high interest due to the development of virtual reality implementation technology and COVID-19 pandemic. The participants were mainly patients(8), and the types of diseases were stroke(2). The physical fitness factors were mostly balance ability(7), muscle strength(7), and range of motion(6). All the physical fitness factors were significantly improved after PATPs. However, 11 studies were conducted for less than 4 weeks, including 6 studies were performed a bout of acute exercise. Also, 14 studies did not clearly present the intensity of PATPs. In addition, there were 9 studies, that simply applied games without specialized programs. In conclusion, it seems that virtual reality-based PATPs have a positive effect on physical fitness factors. However, VR-based PATPs should be specialized and developed in order to verify their effectiveness for the further research.

• Korean Journal of Applied Biomechanics
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• v.29 no.1
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• pp.33-41
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• 2019

Objective: This study aimed to investigate the effect of diminished plantar sensation in Y-balance test between chronic ankle instability (CAI) patients versus Healthy individuals. Method: A total of 90 subjects and CAI group (N=45) (age: $24.49{\pm}2.52yrs$, height: $173.53{\pm}8.20cm$, weight: $69.62{\pm}12.92kg$) and healthy group (N=45) (age: $24.85{\pm}2.70yrs$, height: $170.27{\pm}7.70cm$, weight: $66.04{\pm}11.60kg$) participated in this study. Participants were tested on the anterior (ANT), posterolateral (PL), and posteromedial (PM) reach directions of the Y-Balance Test before and after a 10-minute of plantar cutaneous sensation application using ice ($2^{\circ}C$). Normalized reach distances were measured 3 times each direction. Results: We observed a decrease in reach-distance scores for the reach directions after diminished plantar cutaneous sensation in all reach directions (p<.01). Also, we observed a decrease in reach-distance scores for the PL, and PM reach directions between groups (p<.05). Conclusion: Our results indicated that dynamic postural control was adversely affected immediately after diminished plantar cutaneous sensation between CAI group and healthy group. Future research may suggest that determine the studies involving more realistic dynamic movement, such as walking or running, landing.

• Korean Journal of Applied Biomechanics
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• v.19 no.3
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• pp.603-610
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• 2009

The purpose of this study was to determine how spandex pants affect impact force and muscle activities in the lower extremity. Seven pairs of surface electrodes were attached to the right-hand side of the body. Paired t-test was performed to test if significant difference exist between two conditions(p< .05). The average IEMG activities in the TA, BF, and GM during the landing phase reduced significantly with spandex pants compared to regular pants. All peak IEMG activities except the RF in wearing spandex pants group were significantly greater than the corresponding values in wearing regular pants one. The greater muscle activity recorded in wearing spandex pants can be attributed to the greater motor unit recruitment needed to decelerate and stabilized their bodies. Impact force and loading rate were not significantly decreased with wearing spandex pants. Since the spandex pants used in this study were not custom-fit based on girth of each participants thigh and shank, compression and elasticity for the pants could not be optimized.

• Korean Journal of Applied Biomechanics
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• v.23 no.3
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• pp.253-259
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• 2013

The purpose of this study is to evaluate the influence of posture elements on symmetrical weight bearing during STS (sit-to-stand) in patients with chronic stroke. The subjects were patients diagnosed with stroke: a total of 24 patients (16 males and 8 females) participated in this study. All the participants performed STS tasks(3 foot postures and 2 arm postures). Two force plates (AMTI) were used to measure the peak vertical ground reaction force(Peak Fz) and the symmetrical ratio to peak vertical ground reaction force. The data were analyzed using independent t-test and 2-way repeated analysis of variance. The results of this study were as follows: 1) The peak Fz placed more weight on the paretic leg during STS and 2) The symmetrical ratio to the peak Fz showed a significant difference according to the foot and arm posture (p<.05), and had the highest AYM_GA ($0.87{\pm}0.12$). These results indicate that arm and leg postures during STS in patients with chronic stroke had the highest AYM_GA. We believe that the outcome of this study will be a reference for the prognosis of STS in patients with stroke.