• Title/Summary/Keyword: Ankle strategy

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A Study of Motor Expertise about Kinematic and Kinetic Characteristics of Lower Extremity in the Seokmun Ilwol Martial Art Yin-yang Bo Gait Pattern (석문일월무예 음양보법의 숙련성에 따른 보행 패턴의 하지 운동학 및 운동역학적 특성)

  • Park, Bok-Hee;Kim, Ky-Hyoung
    • Korean Journal of Applied Biomechanics
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    • v.24 no.3
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    • pp.239-248
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    • 2014
  • The purpose of this study was to quantify kinematic and kinetic characteristics of Yin-yang Bo gait according to their motor expertise, one of the Seokmun Ilwol martial art gait patterns. Yin-yang Bo gait pattern shows initial forefoot contact instead of heel contact, and increased time of stance phase time, internal-external rotation of ankle-knee-hip joints and pelvic. It aims to produce and store the more energy through continuous homeostasis of center of gravity (COG) and performance of stretch-shortening cycle. Some of these characteristics also were similar to the gait modification strategies for reducing knee adduction moment such as toe-out progression, medial thrust, internal rotation of hip joint. To identify the characteristics, four factors of expert Yin-yang Bo gait performance group were compared to that of none expert group; 1) angles of COG displacement and rotation 2) distal joint pre-rotation in internal-external rotation of ankle-knee-hip joints and pelvic, 3) invariability pelvic potential and pelvic segment total energy 4) knee abduction moment. Six healthy(three male) subjects participated in the experiment to perform Yin-yang gait pattern. Three-dimensional and force plate data were collected. Kinematic and kinetic data were compared between two groups using t-tests. Results showed that 1) the peak point of COG internal rotation angle was reduced in expert group, 2) kneeexternal and hip joint -internal and pelvic rotation angle peak frames were more near points in expert group.

Comparison of Physical Characteristics and Lower Extremity Biomechanics of Elderly and Young Adult Runners (노인 러너의 신체특성과 하지관절의 생체역학적 비교)

  • Kim, Jong-Bin;Ha, Sunghe;Park, Sangheon;Yoon, Sukhoon;Ryu, Ji-seon;Park, Sang-Kyoon
    • Korean Journal of Applied Biomechanics
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    • v.29 no.3
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    • pp.145-155
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    • 2019
  • Objective: The purpose of this study was to compare the physical characteristics (bone mineral density, joint muscle strength) and running biomechanics between older adults and young adult runners to understand the changes of running strategy by aging. Method: Bone mineral density (Dual Energy X-ray Absorptiometry, USA) of lower lower extremity and muscle strength (Cybex Humac Norm [DEXA], CSMI, USA) were measured to identify the physical characteristics of 10 elderly (age: $67.70{\pm}3.30yrs$, height: $1.68{\pm}0.04m$, mass: $67.70{\pm}3.80kg$) and 10 young adults (age: $21.20{\pm}0.42yrs$, height: $1.73{\pm}0.06m$, mass: $72.11{\pm}4.15kg$). Running data was collected by using an instrumented treadmill (Bertec, USA) and 7 infrared cameras (Oqus 300, Qualisys, Sweden). Two-way repeated ANOVA analysis was used to analyze results at a significant level of .05 with Bonferroni post hoc analysis. Results: Compared to the young adult group, the elderly group showed statistically significant difference in physical characteristics and in running characteristics. Elderly runners showed lower BMD and muscle strength compared with young runners (p<.05). In the running parameters, elderly runners tend to show shorter contact time and stride length compared with young runners (p<.05). In the joint angles, elderly runners showed smaller range of ankle motion compared with young runners (p<.05). Finally, elderly runners showed lower level of joint moment, joint power, and GRF compared with young runners in each running speed (p<.05). Conclusion: The running behavior of the elderly performed periodic running was similar to many variables of young adults. However, there were noticeable differences found in the ankle joints and most kinetic variables compared with young adult runners. This discrepancy may propose that elderly runners should consider appropriate running distance and intensity in the program.

Intervention Strategy Applied ICF Checklists for Sitting Cross-Legged in Patient with Multiple Ligament Knee Injury: Single Subject Study

  • Kim, Chan Yang;Kwon, Jung-Won
    • The Journal of Korean Physical Therapy
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    • v.33 no.3
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    • pp.168-177
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    • 2021
  • Purpose: This study applies the ICF to identify the patient's body function, structure, and participation, evaluates the patient's environmental factors and individual factors, and is a high level of movement to return to the society of patients with multiple ligament injury of the knee joint. Methods: Progressive strength training and ROM exercise were performed 30 minutes a day, 5 times a week for 6 weeks. The evaluation was performed by examining the ROM, length, MMT, instability, dynamic balance, pain and depression. Results: The ROM of the knee joint was improved from 110° to 135° after intervention, and the knee flexion length decreased from 69 cm to 45 cm. Knee flexor is Good after intervention from Poor-, and knee extensor is Good+ after intervention from Poor, and the plantar flexor of the ankle joint improved from Poor- before intervention to Good after intervention and dorsi-flexor of the ankle joint improve to Good from Poor. Pain index was moderate before and after the intervention, with a score of 3, 2 after the intervention, and when maintaining the sitting cross-legged, the before intervention score was 7 to 4 after the intervention. Conclusion: The patient's posture of sitting cross-legged was maintained from 30 seconds before intervention to 14 minutes after intervention. These results were able to set the hypothesis design, intervention method and goal that the multifaceted approach of environment and individual factors as well as body function and structure area, activity and participation area using ICF checklists, it is helped the patient to return to daily life.

Effects of Visual Information Blockage on Landing Strategy during Drop Landing (시각 정보의 차단이 드롭랜딩 시 착지 전략에 미치는 영향)

  • Koh, Young-Chul;Cho, Joon-Haeng;Moon, Gon-Sung;Lee, Hae-Dong;Lee, Sung-Cheol
    • Korean Journal of Applied Biomechanics
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    • v.21 no.1
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    • pp.31-38
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    • 2011
  • This study aimed to determine the effects of the blockage of visual feedback on joint dynamics of the lower extremity. Fifteen healthy male subjects(age: $24.1{\pm}2.3\;yr$, height: $178.7{\pm}5.2\;cm$, weight: $73.6{\pm}6.6\;kg$) participated in this study. Each subject performed single-legged landing from a 45 cm-platform with the eyes open or closed. During the landing performance, three-dimensional kinematics of the lower extremity and ground reaction force(GRF) were recorded using a 8 infrared camera motion analysis system (Vicon MX-F20, Oxford Metric Ltd, Oxford, UK) with a force platform(ORG-6, AMTI, Watertown, MA). The results showed that at 50 ms prior to foot contact and at the time of foot contact, ankle plantar-flexion angle was smaller(p<.05) but the knee joint valgus and the hip flexion angles were greater with the eyes closed as compared to with the eyes open(p<.05). An increase in anterior GRF was observed during single-legged landing with the eyes closed as compared to with the eyes open(p<.05). Time to peak GRF in the medial, vertical and posterior directions occurred significantly earlier when the eyes were closed as compared to when the eyes were open(p<.05). Landing with the eyes closed resulted in a higher peak vertical loading rate(p<.05). In addition, the shock-absorbing power decreased at the ankle joint(p<.05) but increased at the hip joints when landing with the eyes closed(p<.05). When the eyes were closed, landing could be characterized by a less plantarflexed ankle joint and more flexed hip joint, with a faster time to peak GRF. These results imply that subjects are able to adapt the control of landing to different feedback conditions. Therefore, we suggest that training programs be introduced to reduce these injury risk factors.

Effects of Knee Joint Muscle Fatigue and Overweight on Shock Absorption during Single-Leg Landing of Adult Women (성인 여성의 외발 착지 동작 시 무릎관절 근육 피로와 과체중이 충격 흡수에 미치는 영향)

  • Kim, Tae-Hyeon;Youm, Chang-Hong
    • Korean Journal of Applied Biomechanics
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    • v.24 no.1
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    • pp.59-66
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    • 2014
  • The purpose of this study was to investigate the effects of knee joint muscle fatigue and overweight on shock absorption during single-leg landing of adult women. Written informed consent forms, which were approved by the human subject research and review committee at Dong-A University, were provided to all subjects. The subjects who participated in this study were divided into 2 groups: a normal weight group and an overweight group, consisting of 15 young women each. Both the normal weight group and the overweight group showed that use soft landing and ankle dominant strategy. The peak vertical ground reaction force, the knee joint absorption power, and eccentric work done, as the increase of knee joint muscle fatigue level, showed a decrease. And the hip joint absorption power and eccentric work done, as the increase of weight, was less than the overweight group showed the normal weight group. In conclusion, the accumulation of the knee joint muscle fatigue and the increase of body weight may lead to an increased risk of injury during landing.

The Development of a Miniature Humanoid Robot System (소형 휴머노이드 로봇 시스템 개발)

  • Sung, Young-Whee;Yi, Soo-Yeong
    • Journal of Institute of Control, Robotics and Systems
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    • v.7 no.5
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    • pp.420-426
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    • 2001
  • In this paper, we introduce a case study of developing a miniature humanoid robot that has 16 degrees of freedom and is able to perform statically stable walking. The developed humanoid robot is 37cm tall and weighs 1,200g. RC servo motors are used as actuators. The robot can walk forward and turn to any direction on an even surface. It equipped with a small digital camera, so it can transmit vision data to a remote host computer via wireless modem. The robot can be operated in two modes: One is a remote-controlled mode, in which the robot behaves according to the command given by a human operator through the user-interface program running on a remote host computer, the other is a stand-alone mode, in which the robot behaves autonomously according the pre-programmed strategy. The user-interface program also contains a robot graphic simulator that is used to produce and verify the robot\`s gait motion. In our walking algorithm, the ankle joint is mainly used for balancing the robot. The experimental results shows that the developed robot can perform statically stable walking on an even surface.

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The 3-D Motion Analysis of Kinematic Variety on Lower Extremity during Ramp Ascent at Different Inclinations (정상인의 오름 경사로 보행 시 경사각에 따른 하지 관절의 삼차원적 동작 분석)

  • Han, Jin-Tae;Lee, Jong-Dae;Bae, Sung-Soo
    • The Journal of Korean Physical Therapy
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    • v.17 no.4
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    • pp.633-650
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    • 2005
  • The aim of this study was to investigate the kinematics of young adults during ascent ramp climbing at different inclinations. Twenty-three subjects ascended a four step at four different inclinations(level, $8^{\circ},\;16^{\circ},\;24^{\circ}$). The 3-D kinematics was analysed by a camera-based falcon system. Groups difference was tested with one -way ANOVA and SNK test. The different kinematic patterns of ramp ascent were analysed and compared to level walking patterns. The kinematics of ramp walking could be clearly distinguished from the kinematics of level walking. In sagittal plane, Ankle joint was more dorsiflexed at initial contact and Max. dorsiflex. during stance phase with $16^{\circ},\;24^{\circ}$ inclination and more plantarflexed at toe off and Max. plantarflex. during swing phase with $24^{\circ}$(p<.001). Knee joint was more flexed at initial contact with $16^{\circ},\;24^{\circ}$ inclination(p<.001). Hip joint was more flexed at initial contact and Max. flex. during swing phase with $16^{\circ},\;24^{\circ}$ inclination and at toe off with $24^{\circ}$(p<.001) and was more extended at Max. ext. during stance phase with $24^{\circ}$(p<.05). In frontal plane, ankle joint was more everted at Max. eversion. during stance phase with $16^{\circ},\;24^{\circ}$ inclination(p<.001). Knee joint was more increased at Max. varus. during stance phase with $16^{\circ},\;24^{\circ}$ inclination(p<.001). Hip joint was not differentiated with different inclinations. In horizontal plane, all joints were not differentiated with different inclinations. Conclusionally, In ascent ramp walking, the different gait pattern generally occurred at over $16^{\circ}$ on the ascending ramp in sagittal and frontal plane. These results suggest that there is a certain inclination angle or angular range where subjects do switch between a level walking and a ascent ramp walking gait pattern. This shows their motor control strategy between level and ascent ramp walking. Further studies are necessary to confirm and detect the ascent ramp gait patterns.

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Biomechanical Analysis of Lower Limb on Stance during Golf Swing (골프 스윙 시 스탠스에 따른 하지의 역학적 분석)

  • Yoon, Se-Jin;Sul, Jeong-Dug;Woo, Byung-Hoon
    • Journal of the Korean Applied Science and Technology
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    • v.38 no.2
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    • pp.532-542
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    • 2021
  • The purpose of this study was to investigate the body's strategy through kinematic variables of the lower extremities and ground reaction forces to maintain the club-head speed and ball accuracy despite the three stances during the golf swing. Ten male golfers who official handicap two were participate in the experiment. All subjects performed swing after maintaining the address posture according to stance conditions(square; SS, open: OS, closed: CS). Using a 3D motion analysis system and force plateform, the results were calculated with the 7-iron full swing each stance. In result, there was no difference in center of displacement, and left and right hip and knee joint angle displacement. Left ankle joint was largely plantar-flexed in OS, and right ankle joint was largely performed in CS from the address to the downswing. From address to take-back, right foot had a large left direction and the left foot had a right direction were greater in OS than in CS. Therefore, despite various stances, maintaining the same posture at impact is thought to have a positive effect on club head speed and ball direction.

Effects of Changes in Illumination Level and Slope on Fall-Related Biomechanical Risk Factors While Walking for Elderly Women (조도와 주로 변화가 노인 여성 보행 시 낙상 관련 운동역학적 위험요인에 미치는 영향)

  • Jeon, Hyun-Min;Park, Sang-Kyoon
    • Korean Journal of Applied Biomechanics
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    • v.25 no.4
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    • pp.413-421
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    • 2015
  • Objective : The purpose of this study was to investigate biomechanical changes of the lower limb including dynamic stability with changes in illumination (300Lx, 150Lx, and 5Lx) and slope (level and $15^{\circ}$ downhill) as risk factors for elderly falls. Method : Fifteen elderly females were selected for this study. Seven infrared cameras (Proreflex MCU 240: Qualisys, Sweden) and an instrumented treadmill (Bertec, USA) surrounded by illumination regulators and lights to change the levels of illumination were used to collect the data. A One-Way ANOVA with repeated measures using SPSS 12.0 was used to analyze statistical differences by the changes in illumination and slope. Statistical significance was set at ${\alpha}=.05$. Results : No differences in the joint movement of the lower limbs were found with changes in illumination (p>.05). The maximum plantar flexion movement of the ankle joints appeared to be greater at 5Lx compared to 300Lx during slope gait (p<.05). Additionally, maximum extension movement of the hip joints appeared to be greater at 5Lx and 150Lx compared to 300Lx during slope gait (p<.05). The maximum COM-COP angular velocity (direction to medial side of the body) of dynamic stability appeared to be smaller at 150Lx and 300Lx compared to 5Lx during level gait (p<.05). The minimum COM-COP angular velocity (direction to lateral side to the body) of dynamic stability appeared smaller at 150Lx compared to 5Lx during level gait (p<.05). Conclusion : In conclusion, elderly people use a stabilization strategy that reduces walk speed and dynamic stability as darkness increases. Therefore, the changes in illumination during gait induce the changes in gait mechanics which may increase the levels of biomechanical risk in elderly falls.

Study on the Strategy of Muscular Activity for Motor Track of Upper Limbs during Rowing Exercise (로잉운동 시 상지 운동궤적에 따른 근육활성 전략에 관한 연구)

  • Kang, S.R.;Kim, U.R.;Moon, D.A.;Kwon, T.K.
    • Journal of rehabilitation welfare engineering & assistive technology
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    • v.7 no.2
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    • pp.91-99
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    • 2013
  • The purpose of this study was to investigate the muscular activity and muscle strength for swing track of upper limbs during rowing exercise. Subject was all twenty healthy adults and they were divided into linear exercise group and elliptical exercise group in random. Subjects performed rowing exercise 3-times for a week and performed all 8-weeks. We measured realtime-surface EMG. Also we measured joint torque of elbow, ankle and lumbar in subjects using BIODEX. The result showed that when rowing exercise, elliptical track exercise had higher muscular activity in trapezius, deltoid, erector spinae, rectus femoris, biceps femoris, gastronemius than linear track exercise on more many muscle of upper and lower limbs. Also elbow joint torque and lumbar joint torque was more higher too. but linear exercise also had higher muscular activity in multifidus, tibilalis anterior than elliptical track exercise. According to this experiment, we found out that elliptical track was more efficient than linear track.

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