• The Journal of Korean Physical Therapy
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• v.21 no.1
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• pp.35-40
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• 2009

Purpose: The purpose of this study was to investigate change of muscle activities during level walking, stairs and ramp climbing in old adults. Methods: Twelve old adults were recruited and agreed this study. Muscle activity was measured by MP150 system (BIOPAC System Inc., Santa Barbara, USA). Statistical analysis was used one-way ANOVA to know the difference according to gait conditions (level walking, stairs and ramp ascending) Results: In stance phase, muscle activities of low extremities with old adults were generally significant difference in ramp ascending. In swing phase, rectus femoris and biceps femoris activity in old adults generally more increased during stairs ascending and tibialis anterior and gastrocnemius activity in old adults generally increased during ramp ascending. Conclusion: These results indicate that stair and ramp climbing is different muscle recruit pattern to level walking.

• Journal of Biomedical Engineering Research
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• v.33 no.2
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• pp.98-103
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• 2012

The purpose of this study was to compare premotor time(PMT) and electro-mechanical delay(EMD) between sitting and standing posture. Twenty four healthy young subjects(12 women and 12 men) participated in this study. Subjects were instructed to perform maximal, voluntary, isometric contraction of ankle muscle(tibialis anterior and gastrocnemius muscles) in reaction to auditory stimulus. PMT and EMD, calculated from stimulus, EMG and torque profile were compared between sitting and standing postures. As statistical analysis, paired t-test was performed to assess difference between sitting and standing posture. In both tibialis anterior and gastrocnemius muscles, EMD was found to be significantly longer for standing than sitting. However, PMT in standing posture was longer than that in sitting posture only in gastrocnemius muscles. These result indicate that increased reaction time, particularly, increased EMD of ankle muscles in standing posture may be caused by co-contraction of ankle muscles for postural control in standing posture.

• Physical Therapy Rehabilitation Science
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• v.9 no.3
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• pp.197-200
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• 2020

Objective: The purpose of this study was to develop and investigate the feasibility of a sit-to-stand assistive chair using a pneumatic cylinder. Design: Cross-sectional study. Methods: The sit-to-stand assistive chair was developed to assist the sit-to-stand movement by rising up of the chair by a pneumatic cylinder. After the user is seated on the chair, if the pneumatic cylinder pulls the seat plate when standing up, the spring of the pneumatic cylinder, which has been stretched, assists in rising the rear end of the seat plate so that the user can stand conveniently and comfortably. A feasibility test was performed in 10 heathy adults. The electromyographic muscle activation of the trunk and lower extremity muscles was analyzed, which included the erector spinae, rectus abdominis, quadriceps, tibialis anterior, gastrocnemius when standing up from sitting using the developed chair and standing up without using the developed chair. Results: As a result, the sit-to-stand assistive chair using a pneumatic cylinder was developed. In the feasibility test, the use of the developed chair had a decrease in rectus abdominis, quadriceps, tibialis anterior activation compared to those who did not use the device in the healthy adults. Conclusions: The sit-to-stand assistive chair using a pneumatic cylinder may be helpful to reduce the activation of the rectus abdominis, quadriceps, tibialis anterior muscles when performing a sit-to-stand movement. Through the results, the efficacy of the sit-to-stand assistive chair can be confirmed. In the future, further studies are warranted to investigate for the safety and efficacy of its use in the elderly population or those who are disabled.

• Journal of the Korean Society of Physical Medicine
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• v.2 no.2
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• pp.125-134
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• 2007

Purpose : This study is to determine effects of cane-shape which influenced on the change of muscle activation, gait component in hemiplegic patients caused by cerebrovascular accident. Methods : Twenty one stroke patients using T-shape cane(TCG) and twenty one stroke patients using I-shape cane(ICG) participated in this study. Surface electromyography(SEMG) of erector spinae, transvers abdominis, tibialis anterior, soleus of both side were measured during walking without cane and walking with cane. Results : The activation of tibialis anterior was significantly increased in affected side of ICG. The activation of tibialis anterior was significantly decreased in affected side of TCG. The activation of soleus was significantly increased in affected side of ICG. The activation of soleus was significantly decreased in affected side of TCG. The activation of erector spinae was significantly increased in nonaffected side of ICG and TCG. The activation of transvers abdominis was significantly increased in nonaffected side of ICG and TCG. Conclusion : From the finding of this study, it was suggested that I-shape cane increase weight bearing of affected side in hemiplegic patient. Therefore, I-shape cane can be applied to improve gait asymmetry of hemiplegic patients.

• Journal of International Academy of Physical Therapy Research
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• v.2 no.1
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• pp.222-228
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• 2011

With comparison of maximum vertical reaction force and lower limb on drop landing between normal and flat foot group, this study is to provide fundamental data of the prevention of injury and the treatment of exercise which are frequently occurred on flat foot group's drop landing. The surface electrodes were sticked on lateral gastrocnemius muscle, medial gastrocnemius muscle, tibialis anterior and the drop landing on a force plate of 40cm was performed with a normal group who had no musculoskeletal disease and a flat foot group of 9 people who had feet examinations. Vertical reaction force were significantly statistically different between two groups(p<.001). Muscle activity of lower limbs in all three parts were not statistically different but showed high tendency on average in the flat foot group. The flat foot group had difficulties in diversification of impact burden and high muscle activity. Therefore, it was suggested that muscular strengthening of knee joints and plantar flexions of foot joints which were highly affected in impact absorption will be required.

• The Journal of Korean Physical Therapy
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• v.23 no.5
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• pp.49-56
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• 2011

Purpose: The purpose of this study was to investigate the kinematic characteristics and muscle activities during the following two conditions: transition from half-kneel to standing on the affected leg and non-affected leg. Methods: Twenty-one hemiplegic patients participated in the study. A motion analysis system was used to record the range of motion and angle velocity of the hip, knee and ankle from the half-kneel to the standing position. Electromyography was used to record the activity of 4 muscles. Results: The statistical analysis showed that the minimum ROM of the hip joint was less on the affected leg during transition from half-kneel to standing. However, the minimum ROM of the knee and ankle joints was less on the non-affected leg during transition from half-kneel to standing. The angle velocity of the knee and ankle joints was less during transition from half kneeling to standing on the non-affected leg. Muscle activity of the rectus femoris and tibialis anterior was less while moving from half-kneel to the standing position on the affected leg. Conclusion: These results show that greater active ROM of the knee and ankle was required on the affected leg for transition from half-kneel to the standing position than for normal gait. Muscle activity of the rectus femoris and tibialis anterior is normally required for movement from the half-kneel to the standing position during normal gait. Further studies are needed to investigate the antigravity movement in healthy subjects and hemiplegic patients in order to completely understand the normal and abnormal movement from the half-kneel to the standing position.

• Physical Therapy Korea
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• v.9 no.2
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• pp.43-50
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• 2002

This study was designed to identify the effects of walking conditions (normal walking vs. toe-walking) on electromyographic (EMG) activity of gastrocnemius, tibialis anterior, and soleus muscle. Seven healthy adult males participated in this study. The exclusion criteria were orthopedic or neurologic disease, congenital anomaly or acquired deformity, or pain in low back or lower extremities. The maximal voluntary isometric contraction for each muscle was used for the reference contraction, and EMG activity of each muscle during normal walking and toe-walking was expressed as a percentage of reference contraction. The gait cycle was determined with two foot switches, and gait was normalized as 100% gait cycle for each condition. The maximal values of EMG activity in terminal stance (30~50% of gait cycle) of each condition were compared for data analysis. No significant differences were found in EMG activity of the tibialis anterior and soleus (p>.05), whereas significant decrement was found in EMG activity of gastrocnemius during toe-walking compared to normal walking (p<.05). There is a limitation to generalize the results of this study, because small number of subjects participated for this study and only EMG was used for data collection. The treatment methods should be developed to improve gait efficiency by substituting the weakened muscles secondary to upper motor neuron, or by strengthening the distal muscles in lower extremity.

• Korean Security Journal
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• no.19
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• pp.207-223
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• 2009

The main purpose of this study was to analyze the reaction time of body guards in different stances to provide quantification of data for educational use. There were 4 martial art trained body guards participating in this study. The results of the EMG analysis and reaction time are as follows. The average reaction time of the whole body was $1.38{\pm}0.07$ seconds. In the first phase the reaction to the signal was $0.22{\pm}0.02$ seconds while in the second phase the reaction after checking was $0.62{\pm}0.10$ seconds, which produced the largest impulse. the reaction times of the third and fourth phase were gradually reduced, $0.29{\pm}0.02$ seconds and $0.26{\pm}0.02$ seconds consecutively. In the body guard posture the following muscles had a high activity level; phase one the right and left of the tibialis anterior muscle, phase two the right and left of the tibialis anterior muscle and the right of the gastrocnemius, phase three the right side of the tibialis anterior and gastrocnemius, phase four the left and right of the biceps femoris and the right side of the rectus femoris. In the first and second phase the shank muscles were used a lot, whereas in the third and fourth phase the shank and thigh muscles were used a lot showing the overall muscle activation of the lower limbs.

• PNF and Movement
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• v.7 no.3
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• pp.17-27
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• 2009

The purpose of this study was to investigate the effect of close kinetic chain(CKC) and open kinetic chain(OKC) posion on proprioceptive neuromuscular facilitation applied to the unilateral upper extremity on the muscle activation of lower extremity. All subjects were randomly assigned to two groups: open kinetic chain group(n=5),closed kinetic chain group(n=5). All participants were PNF patterns applied on the unilateral upper extremity in all subjects were the kinetic chain(CKC) and open kinetic chain(OKC) posion on flexion/abduction/external rotation. The hold and approximation techniques for the irradiation were applied to end range. All measurements for each subject took the following tests: pre-test, post - test in 4weeks, post-testin 8weeks. EMG data was collected from the vastus medialis, tibialis anterior, biceps femoris, and gastrocnemius muscle of both lower extreamity using surface EMG system, Each EMG value in individual muscle was normalized for maximal voluntary contraction. The data were analyzed using Two-way analysis of variance(ANOVA) with repeated measures to determine the statistical significances. The results of this study are summarized as follows. First, during for close kinetic chain(CKC) and open kinetic chain(OKC) posion on PNF pattern application, all of the %MVIC values of close kinetic chain and open kinetic chain posion increased sign ificantly compared(p<0.05). Second, The close kinetic chain(CKC) and open kinetic chain(OKC) posion on PNF pattern application was significantly increased with in the intervention period(p<.05). Third, there was a no significant open kinetic chain posion on PNF pattern application of sing muscle group with in the intervention period.(p<0.05) there was a significant close kinetic chain posion on PNF pattern application of sing muscle group with with in the intervention period(p<0.05). Forth, interaction of the exercise position and muscle was also significant. Post-hoc tests revealed that the activation levels of vastus medialis muscle and tibialis anterior muscle was higher in the closed kinetic chain position(p<.05). that the activation levels of vastus medialis and gastrocnemius muscle was higher in the open kinetic chain position(p<.05). In conclusion, it was found that the application of PNF patterns to the unilateral upper extremity effect on the muscle activation of lower extremity and both open kinetic chain exercise and closed kinetic chain exercise was significantly increased muscle activity. Further studies are needed to analyzed long term effects and subjects resulting from these changed.

• Korean Journal of Applied Biomechanics
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• v.16 no.2
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• pp.55-63
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• 2006

The purpose of this study was to investigate the effects of vibration exercise using surface electromyography. Seven male collegiate wrestlers were participated in this study. Each subject stood on the platform and the vibration was induced for 1min. WEMG8 EMG system was used to record muscle activity from Vastus lateralis, Biceps Femoris, Tibialis Anterior, and Gastrocnemius. The EMG data were sampled for 30 sec. during non-vibration and vibration half squat position, respectively. The raw data were band pass filtered to remove noise and full wave rectified Paired sample t-test were performed to see the differences of maximum and average EMG between non-vibration and vibration trials. The results indicated that vibration produced much more muscle contraction than that of non-vibration trial for all selected muscles even though the significant difference was found only from Biceps Femoris. This phenomenon was due to the individual differences so care must be taken to evaluate vibration intensity and position before personal training.