• Korean Journal of Applied Biomechanics
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• v.15 no.4
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• pp.117-129
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• 2005

The purpose of this study was to characterize the impact shock wave and its attenuation, and the kinematic response of the lower extremity's joints to the impact shock during downhill running in which the lower extremity's extensor acts dominantly. For this study, fifteen subjects(mean age:$27.08{\pm}4.39$; mass:$76.30{\pm}6.60$; height:$177.25{\pm}4.11$) were required to run on the 0% grade treadmill and downhill grades of 7%, and 15% in random at speed of their preference. When the participant run, acceleration at the tibia and the sacrum and kinematic data of the lower extremity were collected for 20s so as to provide at least 5 strides for analysis at each grade. Peak impact accelerations were used to calculate shock attenuation between the tibia and sacrum in time domain at each grade. Fast Fourier transformation(FFT) and power spectral density(PSD) techniques were used to analyze impact shock factors and its attenuation in the frequency domain. Joint coordinate system technique was used to compute angular displacement of the ankle and knee joint in three dimension. The conclusions were drawn as fellows: 1. Peak impact accelerations of the tibia and sacrum in downhill run were greater than that of 0% grade run, but no significant between conditions. Peak shock of PSD resembled also in pattern of peak impact acceleration. The wave of impact shock attenuation between the tibia and sacrum decreased with increasing grade, but didn't find a significant difference between grade conditions. 2. Adduction/abduction, flexion/extention, and internal/external rotation of the ankle and knee joints at support phase between grade conditions didn't make much difference. 3. At grade of 7% and 15%, there were relationship between the knee of the flexion/extension movement and peak impact acceleration during heel strike and found also it in the ankle of plantar/dorsiflexion at grade of 15%.

• Journal of Biomedical Engineering Research
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• v.30 no.3
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• pp.221-225
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• 2009

The purpose of this study was to investigate the biomechanical effects of an application of whole body vibration during strengthening exercise. Every participant performed four weeks exercise program using general leg-press versus vibrating leg-press. Participants did legpress exercise three sets of 25 repetitions with the load of 25 percent of 1RM during first week, three sets of 20 repetitions with 40 percent of 1RM during second week, three sets of 15 repetitions with 60 percents of 1RM during third week, and three sets of 15 repetitions with 80 percent of 1RM during last fourth week. The vibration(25Hz, 5mm) was applied only to the vibration exercise group. A three dimensional virtual lower extremity model for one of subject and virtual leg-press model were generated. The knee extensor muscle forces were analyzed using the virtual model and the knee joint torque(maximum extension torque) was measured using an isokinetic device. Calculated muscle forces were smaller in vibrating leg-press exercise than in general leg-press exercise. An increase of the maximum knee extension joint torque was 2.14 times larger approximately after the four week vibration leg-press exercise program was performed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.691-700
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• 2016

This study was performed to provide data for developing a more effective and practical pilates exercise program for young women. To meet this purpose, 20 young women were assigned to both groups. The experiment was conducted according to the experimental procedure. Ten subjects in the pilates exercise group performed exercise for 60 minutes everyday at a frequency of 3 days per week for 8 weeks. The subjects in both groups were measured for their physical composition, isokinetic muscular strength in legs, and body balance before and after the experiment. After 8 weeks, the pilates exercise group's body composition showed significantly increased muscular amount (p <.01). There was a statistical increase in knee joint muscle function. For the right knee joint and left knee joint, right knee joint extensor muscle's maximum muscular strength and total work significantly increased under conditions of $60^{\circ}/sec$ (p<.05). Under conditions of $180^{\circ}/sec$, there were statistically significant increases in left knee joint flexor muscle's maximum muscular strength (p<.05). For balance, balance of both legs and right leg showed statistically increases (p<.05).

• The Journal of the Korean bone and joint tumor society
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• v.2 no.1
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• pp.101-105
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• 1996

Prosthetic reconstruction of musculoskeletal defects about the knee for tumor has many advantages, particularly the maintenance of motion and immediate functional restoration. But, prosthetic reconstruction has inherent limitations in terms of long-term durability. The authors have reported here a patient who had mechanical failure at 61 months later following use of a modular resection system to reconstruct the segmental defect of proximal tibia in osteosarcoma. In this case, another technique of extensor mechanism reconstruction using Achilles tendon allograft was attempted. Because of the concerns involving durability of tumor prosthesis, increased emphasis has to be placed on innovation in prosthetic design.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.05
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• pp.179-183
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• 1997

The objective of this study was to develop an FES exercise protocol that can enhance muscle force and fatigue resistance and to evaluate the resulting effects. We investigated contraction and fatigue properties of vasti of 10 normal subjects and 4 paraplegics by applying different types of electrical stimulation. Based on the results, we have been training quadriceps of a male paraplegic patient. The results suggested that the exercise be applied 7 days a week, and confirmed that low frequency and intermittent stimulation delays fatigue. After the two-year FES exercise, the patient's knee extensor torque increased by about ten folds and the fatigue index decreased to half of the preFES value.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.2 no.2
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• pp.25-37
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• 2004

To provide reflection diagnostical basic-data by ultrasonography intended for 38 male/female students used by ultrasound imaging system and dynamometer, compared the MVIC and muscle thickness take an accurate measurement of elbow flexor and knee extensor of thickness and MVIC, in confirmity with distinction of sex and then analysised of correlation in muscle thickness-MVIC, MVIC-weight, weight-muscle thickness, it shows statiscally significant difference MVIC and muscle thickness according to sex. Also there is a high interrelation between two. As well as it shows that there is a different between sex in the MVIC of same thickness and MVIC of same weight. This difference will be related with preportions of muscle fiber type in view of the results by preceded research, it needs to be prerequisite analysis of difference in sex with a great variety of ways hereafter.

• The Journal of Korean Physical Therapy
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• v.10 no.2
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• pp.33-40
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• 1998

This study was carried out to investigate the muscle strength of quadriceps muscles by means of isokinetic test. The experimental objects were devided into electrically stimulated, isotonic and isometric groups and trained for 4weeks. The results were as follows : 1. the values of total work, peak torque, average power and the ratio of peak torque between flexors and extensors revealed singnificant statistically in three experimental groups(p<0.05). 2. The endurance was increased slightly in electrically stimulated group, but decreased in isotonic and isometric group, 3. The value of post training on all items did not reveal significant statistically in three experimental groups(P>0.05). 4. The electrically stimulated groups effected on increasing of muscle strength as isotonic and isometric exercises.

• Journal of Korean Physical Therapy Science
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• v.10 no.1
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• pp.83-89
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• 2003

An electromyogram (EMG) using surface electrodes is one of the indirect tests most frequently used to ascertain muscle fatigue. An EMG can be used in two ways. The first technique determines the root mean square (RMS), which reflects the amplitude of the EMG signal. The second technique determines the median and mean power frequencies through EMG power spectrum analysis. The purpose of this article is for determine the correlation between work and percent root mean square(%RMS) and between work and MDF of EMG based on muscle contractions. It is used the %RMS, which reflects the amplitude of the EMG signal For MDF, it is used the frequency power spectrum analysis method, which involves the fast Fourier transformation (FFT) of the original Signals.

• Physical Therapy Korea
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• v.13 no.1
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• pp.32-37
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• 2006

The purpose of this study was to investigate the effects of clinical characteristics of chronic stroke patients on physiological cost index (PCI) during walking. Fourteen stroke patients participated in this study. To investigate the clinical characteristics, Fugl-Meyer score (FMS), gait velocity (GV), muscle strength of the knee extensor, modified Ashworth scale (MAS) of ankle plantar flexor, devices, and gait patterns during walking were measured and analyzed. The results were as follows: Firstly, use of devices and high MAS of the ankle plantar flexor significantly increased PCI. Secondly, PCI was significantly correlated with the FMS and MAS of the ankle plantar flexor. In conclusion, inhibition of spasticity of the ankle plantar flexor is considered to reduce PCI during walking for chronic stroke patients.

• Journal of Korean Orthopaedic Sports Medicine
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• v.9 no.1
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• pp.7-15
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• 2010

Anterior knee pain syndrome would best be defined as a painful condition that arises in or around the patellofemoral joint and is insidious in onset and bilateral, with an enigmatic entity with multiple causes. Although its etiology is uncertain, the cause is often considered to be abnormal lower limb biomechanics, pathology of extensor mechanism, disorder of patellofemoral joint, malalignment or lateral tracking of the patella, soft tissue tightness, muscle weakness. The measurement of patellar alignment has come to be accepted as an integral part of the examination of anterior knee pain syndrome. Various measurement techniques exist, both clinical and radiological, and these have been frequently used in the diagnosis and treatment of the condition.?Treatment depends on the underlying cause of anterior knee pain and should be directed to the cause rather than to the results. Most often, this involves non-surgical measures, such as anti-inflammatory medications, quadriceps exercises, and hamstring stretching. Shin splint, or medial tibial stress syndrome refers a syndrome of pain running along the inner distal 2/3 of tibia shaft. Shin splint is a common problem for athletes whose sport involves a repeated, jarring impact to the leg. A major factor determining the efficacy of the treatment is that correct diagnosis be made of the problem. The varied etiology has led to the development of several theories as to the cause, treatment, rehabilitation and prevention of shin splint. The management is rest, ice massages, pain relief by medication, and muscle strengthening exercise. Proper rehabilitation and preventative measures can ensure that there is no further recurrence.