• Title/Summary/Keyword: Group velocity

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A Study of Sitting Balance Control between Normal group and with Low Back Pain group According to Eyes Condition Change (정상군과 요통환자군의 시각변화에 따른 자세 균형 조절에 관한 연구)

  • Kim, Beung-Sun;Lee, Suk-Min
    • Journal of Korean Physical Therapy Science
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    • v.10 no.1
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    • pp.109-121
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    • 2003
  • The purpose of this study was to test the difference of sitting balance control between a normal group and a group of patients with low back pain when their eyes were opened or closed. The 30 subjects of the control group had been chosen from healthy individuals who fit into the pre-designed criteria, and the 30 subjects of the experimental group were composed of the patients with LBP who had their treatment from S hospital from september 1, 2002, to October 30, 2002, and the subjects were measured by static balance test by using a balance performance monitor(BPM). Static balance test was done twice for each subject with his or her eyes opened and closed. Collected data were statistically analyzed by SPSS/PC using unpaired T-Test, Pained T-Test and multiple regression. The results were as follows: 1. In static balance test, normal group did not show statistical significance in sway angle(Anterior, Posterior, left and Right), sway path, sway area and maximal sway velocity, but showed statistical significance in mean balance with eyes opened and eyes dosed(P<.05) 2. In static balance test, LBP group did not show statistical significance in sway angle(Anterior, Posterior, left and Right), mean balance, sway path, sway area and maximal sway velocity with eyes opened and eyes dosed 3. With eyes opened, the comparison between the normal group and the LBP group showed statistical significance in sway angle(Anterior, Posterior, left and Right), mean valance, sway path, sway area and maximal sway velocity(p<.05). With eyes closed, normal group and LBP group did not show statistical significance in sway angle(Anterior and Right), sway area, but showed statistical significance in sway angle(Posterior and Left), mean balance, sway path, sway area and maximal sway velocity(p<.05) In conclusion, there was a significant difference in static sitting balance between normal group and LBP patients group. For future studies, I strongly suggest that researches be done on the treatment with LBP by predicting changes of postures and manipulating them.

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A Kinematics Analysis of Handstand of University Students Majoring in Physical Education (사범계 체육전공 대학생 물구나무서기 동작의 운동학적 분석)

  • Kim, Yoon-Ji;So, Jae-Moo;Yeo, Hong-Chul
    • Korean Journal of Applied Biomechanics
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    • v.16 no.4
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    • pp.21-30
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    • 2006
  • The purpose of the study is to search for the possibility of the application of kinematics analysis to physical education at schools and expand its scope of application. This study chose 9 college students majoring in physical education and classified them into type A group who can make the straight, vertical handstand, type B group whose waist is bent, type C group who cannot handstand completely. The center of mass, distance between hand and leg, and the angle and angular velocity of each joint were obtained. The result of this study is this. 1. The time for CM showed 6:4 for A group and 5:5 for B and C groups. The distance between hand and foot in the event 3 was 44% of the height for A group, and 41% for B and C groups. A Group showed the higher CM positional significant difference, it was vertically direction below the hip joint at front. For significant difference of the B Group showed horizontal and vertical velocity of the CM, the highest vertical was obtained in phase 3. The difference of angle of shoulder join in the flexion/extension was showed gradually extension event 2 and the height angular velocity was at phase 3 in the A group. 2 The analysis of the handstand motion revealed that the phase 3, but the maintenance of posture start part the handstand is also very important. Through these results, this study confirmed that the time for phase of the CM, horizontal and vertical positions, velocity, the distance between hands and foot, and the difference of the angle and angular velocity of hip joint and shoulder joint can be set as the variables of analysis. It was also definite cause that the handstand motions of college students majoring in physical education had many difference in performance.

Plyometrics and vibration: no clear winner on efficacy

  • Hubbard, R. Jeremy;Petrofsky, Jerrold S.;Lohman, Everett;Berk, Lee;Thorpe, Donna
    • Physical Therapy Rehabilitation Science
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    • v.3 no.2
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    • pp.86-92
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    • 2014
  • Objective: Whole body vibration (WBV) and plyometrics are common training techniques which increase strength, blood flow, and lower body force and power. The effects these techniques have on sedentary population is unknown. It is our aim to assess the effectiveness of WBV and plyometrics on sedentary population. Design: Experimental study. Methods: Twenty-seven sedentary subjects were assigned to either the control group, jumping only group, or jumping with vibration group. Jump height (myotest or vertec), velocity, force, blood lactates, and rating of perceived exertion (RPE). Subjects were measured on the initial, seventh, and eighteenth visits. Control group attended measurements only. Jumping only and jumping with vibration groups performed jumping from a vibrating platform to a surface 7 1/2 inches higher for 3 bouts of 20 seconds. Each subject in jumping only and jumping with vibration groups attended three times per week for six weeks. Vibration was set at 40 Hz and 2-4 mm of displacement. Results: There was no significant change among groups in force, velocity, vertec height, and myotest height. However there was a significant increase in vertec height from initial to final measure (p<0.05) for jumping with vibration group. RPE was significantly higher between control group and jumping with vibration group after intervention (p<0.05). Conclusions: WBV with vibration increased jump height. Jumping with vibration group experienced increased exertion than for controls. WBV with plyometrics had no effect on force, velocity, blood lactates, or calculated jump height. Further studies controlling for initial measure of blood lactates and using an external focus may be necessary to elicit velocity, force and jump height changes.

Measuring Young's Modulus of Materials by Using Accelerometer (가속도계를 이용한 재료의 영계수 측정방법)

  • Sohn, Chang-Ho;Park, Jin-Ho;Yoon, Doo-Byung;Chong, Ui-Pil;Choi, Young-Chul
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.16 no.11 s.116
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    • pp.1158-1164
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    • 2006
  • For the description of the elastic properties of linear objects a convenient parameter is the ratio of the stress to the strain, a parameter called the Young's modulus of the material. Young's modulus can be used to predict the elongation or compression of an object as long as the stress is less than the yield strength of the material. Conventional method for estimating Young's modulus measured the ratio of stress to corresponding strain below the proportional limit of a material using a tensile testing machine. But the method needs precision specimens and expensive equipment. In this paper, we proposed method for estimating Young's modulus using accelerometer. The basic idea comes from that the wave velocity is different as the Young's modulus. To obtain Young's modulus, a group velocity is obtained. It is difficult to measure group velocity. This is because plate medium has a dispersive characteristics which has different wave speed as frequency. In this paper, we used Wigner-Ville distribution to measure group velocity. To verify the proposed method, steel and acryl plate experiments have been performed. Experimental results show that the proposed method is powerful for estimating Young's modulus.

Measuring Young's Modulus of Materials by using Accelerometer (가속도계를 이용한 재료의 영계수 측정방법)

  • Choi, Young-Chul;Park, Jin-Ho;Yoon, Doo-Byung;Sohn, Chang-Ho;Hwang, Il-Soon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.05a
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    • pp.1027-1032
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    • 2007
  • For the description of the elastic properties of linear objects a convenient parameter is the ratio of the stress to the strain, a parameter called the Young's modulus of the material. Young's modulus can be used to predict the elongation or compression of an object as long as the stress is less than the yield strength of the material. Conventional method for estimating Young's modulus measured the ratio of stress to corresponding strain below the proportional limit of a material using a tensile testing machine. But the method needs precision specimens and expensive equipment. In this paper, we proposed method for estimating Young's modulus using accelerometer. The basic idea comes from that the wave velocity is different as the Young's modulus. To obtain Young's modulus, a group velocity is obtained. It is difficult to measure group velocity. This is because plate medium has a dispersive characteristics which has different wave speed as frequency. In this paper, we used Wigner-Ville distribution to measure group velocity. To verify the proposed method, steel and acryl plate experiments have been performed. Experimental results show that the proposed method is powerful for estimating Young's modulus.

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Change in Autonomic Nerve Responses after Low-frequency Transcutaneous Electrical Nerve Stimulation

  • Lee, Jeong-Woo;Park, Ah-Rong;Hwang, Tae-Yeon
    • The Journal of Korean Physical Therapy
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    • v.22 no.6
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    • pp.71-76
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    • 2010
  • Purpose: The purpose of this study was to examine changes in autonomic nerve responses after low-frequency transcutaneous electrical nerve stimulation (TENS). Methods: Research subjects were 24 students who attend University. Subjects were divided into two groups: 1 = a low intensity group; 2 = a high intensity group. Electrodes were attached to the forearm of the dominant arm and electrical stimuli were administered for 15 minutes. Outcome measures were skin conduction velocity, skin temperature, blood flow, and pulse frequency, each of which was measured a total of 4 times. The data were analyzed using a repeated measures ANOVA. Results: In changes in conduction velocity, the main effect of time variation (in black) was statistically significant. The interaction between time and group main effects was not statistically significant; nor was the difference between the groups. Results showed that skin conduction velocity changed without any relation to group. Conclusions: Low frequency TENS selectively increases skin conduction velocity, which may be helpful for activating sudomotor function regardless of intensity.

Effect of Proprioceptive Exercise on Walking Velocity, Activities of Daily Living and Depression in Elderly Women (고유수용성 운동이 여성노인의 보행속도, 일상생활활동 및 우울에 미치는 영향)

  • Kim, Nan-Soo;Bae, Young-Sook;Um, Ki-Mai
    • The Journal of the Korea Contents Association
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    • v.9 no.2
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    • pp.233-241
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    • 2009
  • The purpose of this study was to evaluate the effects of proprioceptive exercise on walking velocity, activities of daily living(ADL) and depression in elderly women. This study was nonequivalent control group pre-post test design. Subjects were divided into two group(exercise group=17, control group=15). Experimental group conducted proprioceptive exercise program for eight-week. Walking velocity was assessed by 10m-walk test and depression and ADL were assessed by questionnaire. The collected data analyzed by Wilcoxon singed rank test and Mann-Whitney U test. The exercise group significantly improved walking velocity. But control group changes were negligible. The program was effective on walking in elderly women.

The Effect of Pelvic Compression Belt on Gait Velocity, Cadence, Step Length, Stride Length of Gait and Dynamic Balance in Stroke Patients (골반압박벨트가 뇌졸중 환자에서 보행속도, 분속 수, 보장, 활보장, 및 동적 균형에 미치는 영향)

  • Shin, Young-il;Kim, Jin-young;Lee, Ho-jong
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.25 no.1
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    • pp.63-70
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    • 2019
  • Background: The purpose of this study was to determine the effects of a pelvic compression belt on gait abilities and balance in subacute stroke patients. Methods: Twenty two patients with subacute were recruited and randomly assigned into two group: Two group offered conventional physical therapy and occupational therapy for five day. The group was composed of twelve patients. Participants in the experimental group were given the pelvic compression belt and conventional physical therapy, conventional occupational therapy, although conventional physical therapy and occupational therapy provided in the subjects in the control group. To assess the gait ability, the GAITRITE system was used and the Balance system SD was used to test balance. All measurements were performed before and after intervention. Results: The experimental group shows a significant improvement the cadence, velocity, step length and stride length in gait (p<.05) and show significant increase in the dynamic standing balance (p<.05). However, control group shows a significant improvement the cadence, velocity, step length and stride length in gait (p<.05), but shows no significant differences in dynamic standing balance. Furthermore, there were significant differences gait velocity, dynamic standing balance between two groups (p<.05). Conclusions: The results demonstrated that the elastic pelvic belt application is effective to improve gait velocity, dynamic balance in the subacute stroke patients. Thus, the elastic pelvic belt is seemed to be one of the potential methods to facilitate the active rehabilitation program for hemiplegia patients.

The Effects of Gait Ability in the Stroke Patients after Stair Gait Exercise and Lamp Gait Exercise (계단보행훈련과 경사로보행훈련이 뇌졸중 환자의 보행능력에 미치는 영향)

  • Seo, Kyo-Chul;Kim, Hyeun-Ae
    • Journal of the Korean Society of Physical Medicine
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    • v.8 no.3
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    • pp.397-406
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    • 2013
  • PURPOSE: The Purpose of this study was on determine whether stair gait exercise and lamp gait exercise might increase the gait ability of the patients with stroke METHODS: Fourty five patients with stroke were randomly assigned to plane gait exercise group(n=15) and ramp gait exercise group(n=15) and stair gait exercise group(n=15). During four weeks, each group participated thirty minutes for five times per week. Subjects were assessed using pre-value and post-value measurement gait ability(Step length, Heel to heel base of support, Step time, Double support ratio, Gait velocity). RESULTS: These finding suggest that stair gait exercise group was significant in Step length, Heel to heel base of support, Step time, Double support ratio, Gait velocity(p<.05). And lamp gait exercise group was only significant increase in Step time, Gait velocity(p<.05). In comparison of three group, stair gait exercise group was high gait ability than other two groups(p>.05). CONCLUSION: This study showed stair gait exercise group can be used to improve gait ability than other two groups. Thus it indicates that the stair gait exercise group will be more improved through the continued gait program.

Analysis of Gait Velocity, Stance time on Obstacle and Dual Task Gait in Elderly Women with LBP (요통 여성 노인의 장애물과 이중 과제 보행 시 속도 및 입각기 시간 분석)

  • Cho, Yong-Ho;Jeong, Hyeon-Seong;Park, Rae-Joon;Bae, Sung-Soo;Kim, Kyung;Kwon, Yong-Hyun;Cho, Hyuk-Tae;Hawng, Yoon-Tae
    • Journal of the Korean Society of Physical Medicine
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    • v.5 no.4
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    • pp.577-585
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    • 2010
  • Purpose : This study was to evaluate gait velocity and stance time on 5 conditions in elderly women and elderly women with LBP. The subjects were 70's generation. Methods : The subjects are 20 divided into 2 groups. They measured gait velocity, stance-time. The 5 conditions were normal gait, 10cm obstacle gait, 25cm obstacle gait, dual 10cm obstacle gait, dual 25cm obstacle gait. The experimental period was between 2008/12 and 2009/2. Statistical analysis was used Repeated measurement for difference between conditions, independent t-test for difference in two groups. Subjects were countdown from 50 during dual task gait. Results : The results were as follow: there were significantly difference 10cm obstacle velocity, dual 10cm obstacle velocity in two group. The others were not significantly differences. Velocity and stance-time were significantly difference in control group. In dual 25cm obstacle gait, velocity was difference of normal gait. Stance-time was difference in 25cm obstacle gait, and dual 25cm obstacle gait. In Experimental group, velocity and stance-time were not significantly difference. But measured value of velocity was gradually decreased and stance time was increased. Conclusion : These results indicate that elderly people with LBP women are reduced gait ability in dual task, and obstacle condition. So they need to prevent falling in dual task, and obstacle gait and to train obstacle/dual tak gait.