• Proceedings of the Korea Contents Association Conference
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• 2012.05a
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• pp.365-366
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• 2012

본 연구는 교각운동시 불안정한 지지면과 안정적인 지지면을 제공하여 체간 및 하지의 근 활성도의 변화를 알아보고자 하였다. 이 연구의 대상자는 20대 남, 여 14명이었다. 실험방법은 일반적 교각자세와 다이나믹 에어쿠션을 이용한 교각자세를 실시한 후에 무선 8채널 표면근전도 검사기를 이용하여 체간부의 척추기립근, 복직근, 대퇴의 대퇴직근, 외측 슬괵근, 하퇴부의 전경골근, 비복근 외측두에서 근활성 정도를 측정하였다. 체간부의 척추 기립근, 대퇴이두근, 가자미근은 불안정한 지지면에서 근활성도가 높게 나타났다(p<.05). 따라서, 교각운동에서 불안정한 지지면의 제공은 신체의 배측에 위치한 근육의 활성화를 나타내어, 교각운동시 지지면의 안정성의 변화만으로도근육활성도의 변화가 가능함을 알 수 있었다.

• Physical Therapy Korea
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• v.10 no.4
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• pp.1-15
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• 2003

본 연구는 슬관전 신전 직전에 수행된 선행 슬관절 굴곡이 슬관절 신전근의 최대 근력발생 및 근육 활성도(activation)에 미치는 영향을 알아보기 위하여 실시되었다. 16명의 정상인이 Cybex II 등속운동기구에서 3가지 다른 운동 속도($100^{\circ}/s$, $200^{\circ}/s$, $300^{\circ}/s$)와 2가지 다른 근육 활성 조건(선행부하가 없는 조건과 선행부하 조건)에서 슬관절의 최대 신전을 수행하였다. 연구대상자들에게 선행부하 없는 조건에서는 $90^{\circ}$ 슬관절 굴곡 상태에서 $0^{\circ}$까지 최대 신전을 수행하도록 하였고, 선행부하 조건에서는 구심성 슬와부 근육의 구심성 수축으로 $0^{\circ}$에서 $110^{\circ}$까지 굴곡한 후, 다시 $0^{\circ}$까지 최대 신전을 하도록 요구하였다. 종속변인으로는 내측광근과 외측광근의 최대 근전도와 최대 신전근력을 측정하였다. 실험 결과 최대 근전도와 최대 근력 모두 선행부하 조건에서 높게 나타났으며, 운동 속도가 증가함에 따라 최대 근력은 감소하는 전형적인 최대 근력-운동속도 상관법칙이 본 실험에서도 나타났다. 또한 운동속도와 전환속도 간의 간섭이 없는 것으로 나타나, 슬관절 신전근에 선행부하(preloading)를 가하는 것이 최대 근력-운동속도 상관법칙(force-velocity relation)에 영향을 미치지 못하는 것으로 해석되었다. 선행부하로 인해 증가된 최대 근력 및 근 활성도의 증가는 주로 신경촉진에 의한 것으로 해석된다.

• Journal of the Korea Convergence Society
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• v.9 no.11
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• pp.385-391
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• 2018

The purpose of this study was to examine the lower-extremity muscle activation of flat-footed and normal-footed subjects descending stairs while wearing high-heels, thereby identifying any imbalance between the medial and lateral muscles.Thirty female students volunteered to participate in this study. The navicular drop test (NDT) was applied to the selection criteria for the flat-footed group and the normal-footed group. Surface electromyographic data was collected from the medial and lateral quadriceps, hamstrings, and gastrocnemius. Activation of MG and LG was significantly lower in the flat-footed group than in the normal-footed group. Both groups showed significant increases in MQMH and MHMG, but the co-activation in the medial and lateral muscles was lower in the flat-footed group. The co-activation ratios showed a significantly greater MQMH/LQLH in the flat-footed group. Flat-footed subjects who wear high-heels are more likely to experience impaired knee joint alignment than normal-footed subjects. Therefore, flat-footed subjects should use caution when descending stairs while wearing high-heels.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.17 no.2
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• pp.108-112
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• 2024

The pronation foot can increase muscle activity, and may result in muscle fatigue and overuse syndromes. This paper aims to examine the relationships between muscle fatigue indices and pronation angles (PRA) larger than 20° for pronated foot subjects. Twelve subjects in the 15-61 age range were participated, and EMG of their biceps femoris were measured during treadmill walking at 4.5 km/h for 30 seconds. Slopes of the median frequency and the magnitude in the low frequency band were estimated respectively as muscle fatigue indices (MFIs). We hypothesized that the relationships between MFIs and PRA for the subjects in this paper be similar to those for normal ones. The test results demonstrated that we could obtain the significant correlation coefficients between MFIs and PRA (r>0.60; p<0.05).

• Journal of the Korea Convergence Society
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• v.11 no.1
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• pp.83-88
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• 2020

The purpose of this study was to investigate the optimal position among three manual muscle tested positions for upper trapezius in which to obtain an isolated upper trapezius EMG signal for the normalization of upper trapezius muscle EMG activity. A total of 28 healthy adult men participated in the experiment. The UT (upper trapezius) and LS (levator scapulae) muscle activities were measured using the TeleMyo 2400T and analyzed using MyoResearch software. The muscle activity of the US and LS was measured by performing three manual muscle test positions for the upper trapezius. The UT/LS ratio during the S-MVIC was 80.25 and was significantly higher than that during the T-MVIC (76.50; p = 0.011) and the C-MVIC (60.95; p < 0.001). And, the UT/LS ratio during the T-MVIC and was significantly higher than that during the C-MVIC (p < 0.001). Based on the results of present study, we suggest a switch from T-MVIC to S-MVIC for the independent normalization reliability of upper trapezius EMG activity. The UT muscle strength or normalization test using S-MVIC will be able to measure muscle strength or activity of UT compared to previous measurement methods.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.10 no.2
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• pp.107-112
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• 2016

The purpose of this study was to determine the effect of aquatic ramp walking exercise on the activity of the quadriceps, gait and activity of daily living in child with Spinal Muscular Atrophy (SMA) type II. A 5 years-old girl with SMA type II participated in this study. This study used single-subject reverse(A-B-A) design study. There are 12 sessions(4weeks 3 times a week) each during the baseline phase(A), the intervention phase(B), the follow up phase(A). During the baseline phase and the follow up phase performed general aquatic therapy, the intervention phase additional performed walking activity on ramp in pool (60m). Surface electromyogram, Timed Up and Go (TUG) test, ACTIVLIM were used as outcome. During the intervention phase, there were decrease on the activity of the quadriceps. In modified TUG test, gait time reduced during the intervention phase. The ACTIVLIM logit score increased during intervention phase by comparison with the baseline phase. These findings suggest that an aquatic ramp walking exercise activities have the therapeutic possibility on the quadriceps activity and gait ability for child with SMA type II.

• Journal of Digital Convergence
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• v.18 no.2
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• pp.483-487
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• 2020

In this study, the effects of suspension training according to the types of ground. Fourteen healthy male college students measured for the characteristics of core muscle activity in suspension training on two different types of grounds, normal flat and unstable ground using a gym ball. EMG (Electromyography) was exploited to measure the activity of the core muscles according to the types of the ground. Muscle activity of the abdominal muscles, external oblique muscles, internal oblique muscles, and lower lumbar standing muscles was measured. The variables in analyses were measured by the means of % MVC method to standardize the EMG signal according to the ground type for each core muscle. In order to verify the differences in core muscles according to the type of ground the paired t-tests were performed at the significance level of 0.05 (p<.05). As a result of measuring the activity of the core muscles according to the various types of grounds, the difference between muscle characteristics obtained in two different grounds did not appear to be statistically significant. However, the result is an important clue to reconsider the notion that the training effect on the unstable ground is generally superior to the effect on the stable ground in the core muscle training. The type of ground in the core muscle training has been found not to significantly affect the muscle activation according to the results of this study. Regardless of the type of exercise program, hence, the difference in muscle activation will not be insignificant even with the standardized program strengthening core muscles.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.8 no.4
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• pp.259-265
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• 2014

The aims of this study are to investigate the walking intention detection of a rollator based on Infraed (IR) sensor measuring knee joint anterior displacement and leg muscle activities. We used Active Walker attached IR sensor to measure the knee joint anterior displacement and EMG signal of leg muscles(rectus femoris, biceps femoris, tibialis anterior, gastrocnemius) were taken by Delsys bagnli-8ch. Subjects were eight healthy males(age $23.7{\pm}0.5years$, height $175.4{\pm}2.3cm$, weight $70.6{\pm}5.6kg$) and they were involved in experiments which had been proceeded 30 minutes a week, during 3 weeks. This system indicates that the knee joint anterior displacement had the distinction increases according to the gait slope and velocity. We showed the increase of the femoral muscle activities along the anterior tilt and the increase of the crural muscle activities along the posterior tilt.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.3
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• pp.1229-1237
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• 2012

This study aimed to investigate the effect of hand grip force on the activity of shoulder muscles in 2 arm postures. The muscle activity of the upper trapezius, lower trapezius, infraspinatus, anterior deltoid, and posterior deltoid muscles in 22 healthy subjects (11 men and 11 women) were measured using surface electrodes during 4 hand gripping tasks (0%, 30%, 50%, and 70% of maximum voluntary contraction) in 2 shoulder positions (neutral position and $90^{\circ}$ elevation position). Among changing grip force significantly differenced infraspinatus, anterior deltoid, and posterior deltoid muscles' activity in the shoulder neutral position(p<0.05). In the shoulder $90^{\circ}$ elevation position, anterior deltoid, posterior deltoid muscles' activity was significantly differenced(p<0.05). Hand gripping was found to alter muscle activation. The hand grip task activated the infraspinatus muscle in the neutral position and inhibited the deltoid muscle in the $90^{\circ}$ elevation position. This finding may prove useful for the development preventative measures and rehabilitation strategies for shoulder injuries.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.1
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• pp.220-226
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• 2012

The purpose of this study was to identify the effect of treadmill gradient training on lower limb muscle activity in chronic stroke patients. The subject were 32 stroke patients.. Subjects were randomly divided into three group which were control group($0^{\circ}$treadmill training(n=10)) and experimental group($5^{\circ}$treadmill training (n=10) and $10^{\circ}$treadmill training(n=12)). Three groups received treadmill gradient training for 30 minutes while 3 times per week for 6 weeks in addition to conventional physical therapy. Muscle strength was measured by EMG on rectus femoris, biceps femoris, tibialis anterior and gastrocnenius for muscle activities. In comparison of activity of rectus femoris and gastrocnemius between pre and post value, the activity of rectus femoris was significant in the experimental and control group(p<.05) and the activity of biceps femoris was significant in the $5^{\circ}$treadmill gait training group and $10^{\circ}$treadmill gait training group(p<.05). The activity of tibialis anterior was significant in the $5^{\circ}$treadmill gait training group and $10^{\circ}$treadmill gait training group(p<.05). In comparison of the difference of activity of rectus femoris among 3 groups, there was a significant difference between the $5^{\circ}$treadmill gait training group and control group(p<.05). and difference of activity of tibialis anterior was significant difference between the $10^{\circ}$treadmill gait training group and control group(p<.05). These findings suggest that $5^{\circ}$treadmill gait training group and $10^{\circ}$treadmill gait training group can be used to improve lower limb muscle activity in chronic stroke patient. In conclusion, these treadmill gradient training helped improving function of gait ability in chronic stroke patient.