• 대한물리의학회지
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• 제15권4호
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• pp.131-143
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• 2020

PURPOSE: The purpose of this study was to determine if an exercise program with vertical vibration can improve balance, walking speed, muscle strength and falls efficacy in the healthy elderly. METHODS: A total of 28 elderly were randomly divided into two groups: vertical vibration exercise group (exercise with vertical vibration) (N = 14) and control group (exercise without vibration) (N = 14). The exercise program, comprising calf raise, deep-squat, semi-squat, front lunge, and leg abduction was conducted with or without vibration, respectively. Subjects in each group participated in the 30 minutes training program, 2 times per week for 6 weeks. In both groups, the balance evaluation system (BT4) was used to evaluate standing balance, and walking speed was measured using the 10MWT. The manual muscle test system was applied to evaluate the knee extensor and ankle planter flexor muscle strength of the subjects, whereas the Korean falls efficacy scale (K-FES) evaluated the falls efficacy. RESULTS: After intervention, the vertical vibration group showed significantly higher changes compared to the control group, in the parameters of standing balance (P < .05), 10MWT (P < .05), left knee extensor (P < .05), right knee extensor (P < .01), both ankle plantar flexors (P < .05), and K-FES (P < .05). CONCLUSION: The exercise program with vertical vibration has the potential to improve balance, walking speed, muscle power and falls efficacy in the elderly.

• 한국운동역학회지
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• 제34권2호
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• pp.45-52
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• 2024

Objective: The purpose of this study was to measure the morphological characteristics of the foot and biomechanical variables of the lower extremity joints during vertical jump and investigate the relationship between foot morphology and biomechanics of vertical jump. Method: 24 men in their 20s (age: 22.42 ± 1.41 yrs, height: 173.37 ± 4.61 cm, weight: 72.02 ± 6.21 kg, foot length: 251.70 ± 8.68 mm) participated in the study. Morphological characteristics of the foot included the length of the first toe, the length of the second toe, and the horizontal length from the center of ankle joint to the achilles tendon (Plantar Flexion Moment Arm [PFMA]). Biomechanical variables were measured for plantar flexor strength of the ankle joint and peak angular velocity, moment, and power of the lower extremity joint during vertical jump. Results: There was a significant correlation between the length of the first toe and plantar flexion strength at 30°/s [r=.440, p=.016], the angular velocity of the metatarsophalangeal [MTP] joint [r=-.369, p=.038] while significant correlations between PFMA and the angular velocities of the knee joint [r=.369, p=.038] and ankle joint [r=.420, p=.021] were found. There were also significant correlations between the length of the first toe and the maximum moment of the hip joint [r=.379, p=.034], and the length of the second toe and the power of the hip joint [r=-.391, p=.029]. Finally, significant correlations between PFMA and the power of the ankle joint [r=.424, p=.019] and MTP joint [r=.367, p=.039] were found. Conclusion: Based on the results of this study, the length of the toe and PFMA would be related to the function of the lower extremity joint. Therefore, this should be considered when designing the functional structure of a shoe. Furthermore, this relationship can be applied to intensive training for the plantar flexors and toe flexors to improve power in athletic performance.

• 한국운동역학회지
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• 제17권4호
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• pp.57-64
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• 2007

The purpose of this study was to investigate comparative analysis of the vertical ground reaction force variables during landing from vertical jump blocking in volleyball through GRF analysis system. The subjects participated in this study were 6 male university volleyball player and 6 male acted as a control group. The results are as follows: 1. The skilled group was longer than the unskilled group in flight time during vertical jump blocking. 2. The skilled group was faster than the unskilled group in tFz2 during landing from vertical jump blocking. 3. The skilled group was higher than the unskilled group in Fz2 during landing from vertical jump blocking. 4. The skilled group was higher than the unskilled group in Fz2LR during landing from vertical jump blocking. 5. The skilled group was higher than the unskilled group in impulse during landing from vertical jump blocking. Consequently, during landing from vertical jump, the landing strategy of the skilled group was found as a form of a stiff landing. Therefore, this landing strategy will be required to strengthen of hip and knee extensors and ankle plantar flexors for injury prevention.

• 대한정형도수물리치료학회지
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• 제15권2호
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• pp.1-7
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• 2009

Purpose : to investigate change of isokinetic muscle strength and isokinetic muscle endurance of quadriceps femoris and hamstring after application of taping and static stretching. Methods : For this study, 14 male members of college soccer team participated in this research. Participants were divided into two groups: seven was assigned to a taping group(n=7) and the others were assigned to a static stretching exercise group(n=7). Main outcome was measured by using biodex. The isokinetic muscle strength test was processed at the speed of the $60^{\circ}$/sec five times, and isokinetic muscle endurance was processed at the speed of $180^{\circ}$/sec ten times. Results : From the outcomes of the measurement, the results show that there is a more significant difference in the taping group than in a static stretching exercise group. Conclusion : These results will be utilized for the preliminaries in the future.

• 한국전문물리치료학회지
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• 제16권3호
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• pp.9-15
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• 2009

The purpose of this study was to examine contraction of abdominal muscles on surface electromyographic (EMG) activity of superficial cervical flexors, rib cage elevation and angle of craniocervical flexion during deep cervical flexion exercise in supine position. Fifteen healthy subjects were participated for this study. All subjects performed deer cervical flexion exercise with two methods. The positions of two methods were no volitional contraction of abdominal muscles in hook-lying position with 45 degree hip flexion (method 1) and 90 degrees hip and knee flexion with feet off floor for inducing abdominal muscle contraction (method 2). Surface EMG activities were recorded from five muscles (sternocleidmastoid, anterior scaleneus, recuts abdominis, external oblique, internal oblique). And distance of rib cage elevation and angle of craniocervical flexion were measured using a three dimensional motion analysis system. The EMG activity of each muscle was normalized to the value of reference voluntary contraction (%RVC). The EMG activities, distance of rib cage elevation. and angle of craniocervical were compared using a paired t-test between two methods. The results showed that the EMG activities of sternocleidmastoid and anterior scaleneus during deep cervical flexion exercise in method 2 were significantly decreased compared to method 1 (p<.05). Distance of rib cage elevation and angle of craniocervical flexion were significantly decreased in method 2 (p<.05). The findings of this study indicated that deep cervical flexion exercise with contraction of abdominal muscles could be an effective method to prevent substitute motion for rib cage elevation and contraction of superficial neck flexor muscles.

• 한국전문물리치료학회지
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• 제10권1호
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• pp.109-128
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• 2003

This study tested whether repeated measurement of median frequency (MDF)-related variables could express the muscle power changes during a 12-week DeLome strengthening program, by using consecutive overlapping FFT (Fast Fourier transformation) and integrated EMG (IEMG) from surface EMG data for isometric and isotonic exercise. To evaluate the effect of training, the following were recorded every 3 weeks for the elbow flexors and knee extensors of 5 healthy male volunteers: MVC, lRM, limb circumference, and surface EMG during isometric MVC or isotonic contraction at 10RM load. From the EMG data, IEMG and variables from a regression analysis between MDF and time were obtained. MVC, lRM, IEMG, and initial MDF increased linearly over the training period. The fatigue index and slope of the regression line increased temporarily until the 6th week and decreased thereafter. From these results, there appeared to be enhanced neural recruitment of fast twitch fibers in the first 6 weeks and continued enhancement in the recruitment and hypertrophy of fast twitch fibers, which led to increased fatigue resistance, over the last 6 weeks. Accordingly, the MDF and IEMG analysis technique could demonstrate the effect of the program detected significant changes in both isometric and isotonic contractions. EMG analysis methods can be used to estimate the electrophysiological and histological changes in skeletal muscles during a strengthening program.

• Safety and Health at Work
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• 제10권3호
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• pp.321-326
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• 2019

Background: Performing cognitive tasks and muscular fatigue have been shown to increase muscle activity of the lower extremity during quiet standing. A common intervention to reduce muscular fatigue is to provide a softer shoe-surface interface. However, little is known regarding how muscle activity is affected by softer shoe-surface interfaces during static standing. The purpose of this study was to assess lower extremity muscular activity during erect standing on three different standing surfaces, before and after an acute workload and during cognitive tasks. Methods: Surface electromyography was collected on ankle dorsiflexors and plantarflexors, and knee flexors and extensors of fifteen male participants. Dependent electromyography variables of mean, peak, root mean square, and cocontraction index were calculated and analyzed with a $2{\times}2{\times}3$ within-subject repeated measures analysis of variance. Results: Pre-workload muscle activity did not differ between surfaces and cognitive task conditions. However, greater muscle activity during post-workload balance assessment was found, specifically during the cognitive task. Cognitive task errors did not differ between surface and workload. Conclusions: The cognitive task after workload increased lower extremity muscular activity compared to quite standing, irrespective of the surface condition, suggesting an increased demand was placed on the postural control system as the result of both fatigue and cognitive task.

• 한국산학기술학회논문지
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• 제14권12호
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• pp.6353-6363
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• 2013

본 논문은 농촌지역 재가 노인의 낙생재발과 관련된 위험요인을 분석함으로써 낙상재발 방지 프로그램을 개발하는데 근거자료로 제공하고자 시도하였다. 본 연구의 대상자는 낙상 횟수에 따라 비낙상자, 1회 낙상자, 낙상재발자로 구분하였으며 대상자는 329명이었고 자료수집은 2010년 2월 5일부터 2월 14일까지 실시하였다. 329명 노인 중 1회 낙상자는 14.3%, 낙상재발자 4.0%이었다. 세 군간에 정적 균형(한발서기 시간)(F=5.86, p=.003), 동적 균형(3m 걸어갔다 돌아오는 시간)(F=24.32, p<.001), 낙상 위험도(F=9.94, p<.001), 낙상예방행위이행도(F=3.09, p=.047)는 유의한 차이가 있었다. 상관관계 분석에서 낙상 횟수와 슬관절 굴곡근 근력(r=-.15, p=.008), 정적 균형(r=-.16, p=.004), 낙상예방행위이행도(r=-.12, p=.030)는 역상관관계가, 동적 균형(r=.26, p<.001), 우울(r=.13, p=.019), 낙상위험도(r=.30, p<.001)는 순상관관계가 있었다. 낙상 횟수와 유의한 상관관계가 있는 변수를 활용하여 투입식 회귀분석을 실시한 결과 설명력 36.0%로 유의한 것으로 나타났다. 이와 같은 본 연구결과를 근거로 농촌지역 재가 노인의 낙상재발을 방지하기 위해서는 노인의 균형을 증진시킬 수 있는 신체활동과 우울을 감소시킬 수 있는 심리적 중재 및 낙상예방행위를 이행할 수 있는 행동요법 등이 포함된 복합 낙상재발 방지 프로그램을 제안한다.