• 한국운동역학회지
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• 제22권1호
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• pp.25-34
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• 2012

The purpose of this study was to determine the effects of landing height on the lower extremity during a counter movement jump. Fourteen healthy male subjects (age: $27.00{\pm}2.94$ yr, height: $179.07{\pm}5.03$ cm, weight: $78.79{\pm}6.70$ kg) participated in this study. Each subject randomly performed three single-leg jumps after s single-leg drop landing (counter movement jump) on a force platform from a 20 cm and 30 cm platform. Paired t-test (SPSS 18.0; SPSS Inc., Chicago, IL) was performed to determine the difference in kinematics and kinetics according to the height. All significance levels were set at p<.05. The results were as follows. First, ankle and knee joint angles in the sagittal plane increased in response to increasing landing height. Second, ankle and knee joint angles in the frontal plane increased in response to increasing landing height. Third, there were no significant differences in the moment of each segment in the sagittal plane for the jumping height increment. Fourth, ankle eversion moment and knee valgus moment decreased but hip abduction moment increased for the jumping height increment. Fifth, Ankle and knee joint powers increased. In percentage contribution, the ankle joint increased but the knee and hip joints decreased at a greater height. Lastly, as jumping height increased, the power generation at the ankle joint increased. Our findings indicate that the height increment affect on the landing mechanism the might augment loads at the ankle and knee joints.

• Physical Therapy Rehabilitation Science
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• 제6권2호
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• pp.96-104
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• 2017

Objective: The purpose of this study was to investigate the effect of the hip joint strengthening exercises using proprioceptive neuromuscular facilitation (PNF) on the clinical symptoms and the treatment effects in balance, sit to stand, and gait abilities in patients with TBI. Design: A single case study. Methods: A 13-year-old adolescent with quadriplegia and hip joint control impairment participated in this four-week training intervention. The patient, diagnosed with TBI, wastreated with hip joint strengthening exercises using PNF. In the first week, we focused on strengthening the body, relaxing the hip flexors and activating the hip extensor muscles in order to solve the patient's physical function and body structure. From the 2nd and 4th week, we improved the motivation through the task-oriented method, and then weight-bearing training of the right lower extremity was proceeded by kicking a soccor ball with the left lower extremity. The exercises were performed for 4 weeks, 5 days a week, for 60 minutes with the exercise intensity gradually increased according to the subject's physical abilities. Results: As a result of the study, the patient demonstrated improvements in the physical examination, which were evaluated before and after intervention and included the manual muscle test, modified Ashworth scale, sensory assessment, coordination assessment, Berg balance scale, 5-time sit to stand test, and the 10 meters walk test. Conclusions: The results of this case suggest that a hip joint strengthening exercise program using PNF may improve hip control ability, balance, sit to stand and gait ability in a patient with TBI.

• 한국운동역학회지
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• 제25권2호
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• pp.191-198
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• 2015

Objective : The purpose of this study was to conduct biomechanical analysis of varying backpack loads on the lower limb movements during downhill walking over $-20^{\circ}$ ramp. Method : Thirteen male university students (age: $23.5{\pm}2.1yrs$, height: $175.7{\pm}4.6cm$, weight: $651.9{\pm}55.5N$) who have no musculoskeletal disorder were recruited as the subjects. Each subject walked over $20^{\circ}$ ramp with four different backpack weights (0%, 10%, 20% and 30% of body weight) in random order at a speed of $1.0{\pm}0.1m/s$. Five digital camcorders and two force plates were used to obtain 3-d data and kinetics of the lower extremity. For each trial being analyzed, five critical instants were identified from the video recordings. Ground reaction force, loading rate, decay rate, and resultant joint moment of the ankle and the knee were determined by the inverse dynamics analysis. For each dependent variable, one-way ANOVA with repeated measures was used to determine whether there were significant differences among four different backpack weight conditions (p<.05). When a significant difference was found, post hoc analyses were performed using the contrast procedure. Results : The results of this study showed that the medio-lateral GRFs at RHC in 20% and 30% body weight were significantly greater than the corresponding value in 0% of body weight. A consistent increase in the vertical GRFs as backpack loads increased was observed. The valgus joint movement of the knee at RTO in 30% body weight was significantly greater than the corresponding values in 0% and 10% body weight. The increased valgus moment of 30% body weight observed in this phase was associated with decelerating and stabilizing effects on the knee joint. The results also showed that the extension and valgus joint moments of the knee were systematically affected by the backpack load during downhill walking. Conclusion : Since downhill walking while carrying heavy external loads in a backpack may lead to excessive knee joint moment, damage can occur to the joint structures such as joint capsule and ligaments. Therefore, excessive repetitions of downhill walking should be avoided if the lower extremity is subjected to abnormally high levels of load over an extended period of time.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2009년도 춘계학술대회 논문집
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• pp.939-940
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• 2009

• 한국운동역학회지
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• 제21권1호
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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.

• 대한인간공학회지
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• 제27권3호
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• pp.93-101
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• 2008

Wedged soles and rocker soles are widespread shoe designs used to prevent the disorders and reduce the pain of the lower extremity caused by arthritis or diabetic feet. In this study, the effect of a shoe with a laterally wedged sole and a rocker sole simultaneously was analyzed on the kinematics and kinetics of the ankle joint during normal walking. Eight male participants without a history of lower extremity disorders were recruited. Each participant performed twenty walking cycles for each of three walking conditions: bare foot, wearing normal shoes and wearing shoes with laterally wedged rocker soles. The differences between the three walking conditions were statistically investigated including spatio-temporal variables, angular displacements, joint moments and ground reaction forces. The results showed that the laterally wedged rocker sole decreased the sagittal variation of angular displacements as well as the frontal/sagittal average moment on the ankle joints compared to the flat sole. In addition, the rate of angular displacements and loading decreased during the heel contact phase.

• 근관절건강학회지
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• 제18권1호
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• pp.83-92
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• 2011

Purpose: The purpose of this study was to identify the changes of physical function, perceptual and cognitive function, emotional function, and functional independence in the institutionalized aged according to functional group activity program (self help Tai Chi exercise plus functional task). Methods: Study subjects were 20 institutionalized aged from June to October in 2010. The subjects received functional group activity program two times a week for 15 weeks. Physical function (grip strength, coordination, lower extremity strength, balance, gait, trunk flexibility), perceptual and cognitive function, emotional function(depression, social skill), and functional independence were measured before and after the program. Results: The subjects showed significantly increased physical function (coordination, lower extremity strength, gait, trunk flexibility), perceptual and cognitive function, emotional function (depression, social skill), and functional independence. The functional group activity program may be an effective strategy for institutionalized elders to enhance their functions. Conclusion: The functional group activity program may be effective on elderly institutions which have limitation in human, material, environmental resources.

• The Journal of Korean Physical Therapy
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• 제10권1호
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• pp.213-221
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• 1998

The purpose of this study was a motion analysis of proprioceptive neuromuscular facilitation patterns which is scapular and pelvis patterns, upper extremity patterns, lower extremity patterns, trunk patterns. The patterns combine motion in sagittal plane for flextion and extension, coronal or frontal plane for abduction and adduction, transverse plane for rotation. The patterns composed of mass movement pattern of the limbs and trunk muscles. Every pattern can change by changing the activity of the middle joint in the extremity patterns and changing the patient's positions.

• 한국운동역학회지
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• 제16권2호
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• pp.121-134
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• 2006

The purpose of this study was to analyze the effect of different types of rehabilitation training program on the kinetic and kinematic parameters during sit-to-stand movement(STS) in chronic stroke patients. Two groups of hemiparetic patients, experimental and control, participated in the study. The experimental group participated in a 10-week training program (three sessions/wk, $1{\sim}1.5\;hr/session$) consisting of a warm-up, aerobic exercises, lower extremity strengthening. and a cool-down. The control group participated in an aerobic exercise. Three dimensional kinematic analysis and force platform; were used to analyze the duration of STS, lower extremity angle, and weight bearing ability. The experimental group which had more strength of lower extremity displayed decrease in duration of STS. However, the control group showed increases in duration during sit-to-stand movement. The control group flexed their trunk more than the group did Therefore, it took more time to extend their trunk during STS. The duration in sit-to-stand was affected by the strength of lower extremity and the angle of trunk movement. The angles of ankle and knee joint had an influenced on duration of STS. The post experimental group performed with their feet near the front leg of the chair during sit-to-stand, therefore the duration was decreased. The repetitive sit-to-stand movements as a resistance exercise was effective to hemiparetic patients in learning mechanism of sit-to-stand. The control group showed decreased differences in the vertical ground reaction forces between paretic and non-paretic limbs. Their training program included strengthening exercise that may help improving weight bearing ability. The control group showed increases in the center of pressure in the anteroposterior and mediolateral displacement. This means that the stability of movement was low in the control group. Their training program which combined aerobic and strengthening exercises that are more effective to improve the stability of movement.

• 대한임상전기생리학회지
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• 제10권1호
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• pp.1-5
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• 2012

Purpose : In this study, stroke patients' limits of stability and functional reach test and tibialis anterior, gastrocnemius muscle of lower extremity muscle activities to evaluate the correlation. Methods : 30 adult stroke patients to participate in this study. Limits of stability were measured using biorescue, tibialis anterior and gastrocnemius muscle of muscles activities were measured with functional reach test when there was movement. Results : Limits of stability and functional reach test (r=0.753, p<0.01), RMS value of the limits of stability and tibialis anterior muscle (r=0.706, p<0.01), RMS value of the limits of stability and gastrocnemius muscle (r=0.766, p<0.01), RMS value of the functional reach test and tibialis anterior muscle (r=0.835, p<0.01), RMS value of the functional reach test and gastrocnemius muscle (r=0.663, p<0.01), RMS value of the tibialis anterior and gastrocnemius muscle (r=0.816, p<0.01) correlations are shown as statistically significant. Conclusion : The balance and lower extremity muscle activities of stroke patients were studied, and were positively correlated with the RMS value of the limits of stability and functional reach test, tibialis anterior muscle, and gastrocnemius muscle. This study has shown that stroke patients' ankle joint muscle activity can greatly.