• Physical Therapy Rehabilitation Science
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• 제12권1호
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• pp.26-32
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• 2023

Objective: This study attempted to compare the effects of bridge exercise using a sling according to the angle of the ankle to confirm the effective lower extremity muscle activation posture of patients with patellofemoral pain syndrome(PFPS). Design: Cross-sectional study Methods: Seventeen patients with PFPS were recruited and the muscle activities of the vastus medialis, vastus lateralis, rectus femoris, and gluteus maximus were measured according to the ankle position (dorsiflexion, neutral, plantar flexion). After measuring the maximum number of isometric contractions of vastus medialis, vastus lateralis, rectus femoris, and gluteus maximus, bridging exercise using a sling according to each ankle posture was applied to measure lower extremity muscle activity. The evaluation was performed 3 times for 10 seconds. The three ankle postures were randomly performed and the average values were compared. Results: As a result of this study, the vastus medialis muscle showed high muscle activity in the order of dorsiflexion, plantar flexion, and neutral position bridge exercise (p<0.05). And the vastus lateralis showed high muscle activity in the order of dorsiflexion, neutral, and plantar flexion (p<0.05). However, rectus femoris and gluteus maximus did not show significant muscle activity according to the ankle posture, but muscle activity was highest in the dorsiflexion posture. Conclusions: As a result of this study, muscle activity was high in the order of vastus medialis and vastus lateralis during ankle dorsiflexion. This is thought to be a major factor that can be applied in various ways in clinical practice according to the ankle angle when treating PFPS patients.

• The Journal of Korean Physical Therapy
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• 제32권1호
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• pp.52-57
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• 2020

Purpose: This study compared the muscle activities of the Vastus medialis oblique (VMO) and the Vastus lateralis (VL) at three different knee extension angles: 90°, 135°, and 180° in the sitting position. Methods: Twenty subjects between 20 and 30 years of age participated in the study. A mobile phone application called the Clinometer was used to measure the knee joint angle. Electromyography (EMG) was performed to measure the muscle activities of the VMO and VL muscles during knee isometric extension exercises. The pulling sensor was used to maintain 70% of the maximum strength of the knee extensor continuously in the sitting position. After attaching the EMG sensor, the subjects were asked to perform isometric knee extension exercises randomly among three knee extension angles (90°, 135°, or 180°) in the sitting position. One-way repeated measures analysis of the variance and a Bonferroni post hoc test was used to identify the VMO and VL muscle activity during knee extension angles among 90°, 135°, and 180°. Results: The VMO and VL muscle activities increased with increasing knee extension angle in the sitting position (p<0.01). Conclusions: Knee extension exercise at a 180° angle in the sitting position can be recommended to increase the muscle activity of the VMO and VL muscle activities efficiently.

• 대한임상전기생리학회지
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• 제4권1호
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• pp.27-38
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• 2006

This study analyzed changes in action potential of supraspinal neuron and motor unit depending on maximum tolerance isometric contraction(MTIC) by electrical stimulation and examined influence of functional electrical stimulation (FES) on spinal neuron adaptation. It selected 40 university students in their twenties and divided into experimental groups of 25% MTIC(I), 50% MTIC I (II), 75% MTIC(III) and 100% MTIC(IV) depending on MTIC by electrical stimulation, and performed isometric contraction of plantar flexor muscle to each experimental group with given contraction for 20 times. It measured V/Mmax and MDF pre and post exercise, compared volume of contraction. 1. V/Mmax ratio showed no significant difference in comparison among experimental groups. 2. There was significant difference in median frequency of gastrocnemius and soleus in action potential motor unit according to comparison among experimental groups(p<.001). When contraction by electrical stimulation was maximum, change was greatest. This results suggest that muscle contraction by electrical stimulation was influence to action potential of spinal motor neuron system which appear optimal level though aspect and difference degree were not in accordance. Consequently, optimal stimulation level of MTIC(50%) by FES would be lead to central nerve adaptation. muscle contraction by electrical stimulation was influence highly to MDF which should be consider to fatigue of motor unit for muscle contraction by electrical stimulation.

• 한국전문물리치료학회지
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• 제10권1호
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• pp.109-128
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• 2003

This study tested whether repeated measurement of median frequency (MDF)-related variables could express the muscle power changes during a 12-week DeLome strengthening program, by using consecutive overlapping FFT (Fast Fourier transformation) and integrated EMG (IEMG) from surface EMG data for isometric and isotonic exercise. To evaluate the effect of training, the following were recorded every 3 weeks for the elbow flexors and knee extensors of 5 healthy male volunteers: MVC, lRM, limb circumference, and surface EMG during isometric MVC or isotonic contraction at 10RM load. From the EMG data, IEMG and variables from a regression analysis between MDF and time were obtained. MVC, lRM, IEMG, and initial MDF increased linearly over the training period. The fatigue index and slope of the regression line increased temporarily until the 6th week and decreased thereafter. From these results, there appeared to be enhanced neural recruitment of fast twitch fibers in the first 6 weeks and continued enhancement in the recruitment and hypertrophy of fast twitch fibers, which led to increased fatigue resistance, over the last 6 weeks. Accordingly, the MDF and IEMG analysis technique could demonstrate the effect of the program detected significant changes in both isometric and isotonic contractions. EMG analysis methods can be used to estimate the electrophysiological and histological changes in skeletal muscles during a strengthening program.

• 한국운동역학회지
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• 제24권4호
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• pp.399-415
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• 2014

The aim of this study was to investigate the effect of resistance training with and without whole-body vibration(WBV) on the biomechanical properties of the plantarflexor in the elderly women (>60 yrs., n=35). Thirty-five volunteers were randomly assigned to a resistance training with WBV group (RVT, n=14), a resistance training without WBV (RT, n=11), and a non-training control group (CON, n=10). The RVT and the RT groups participated in the training sessions three times a week for 8 weeks, followed by a 4-week detraining period. The CON group was instructed to refrain from any type of resistance training. To assess strength and activation of the plantarflexor muscles, maximum isometric ankle plantarflexion torque and muscle activation of the triceps surae muscles were measured using dynamometry, twitch interpolation technique and electromyography at four different ankle joint angles. Also, the lower extremity function was assessed by vertical jumping. The measurements were performed prior to, 2 and 8 weeks after the training and after a 4-week detraining period. Following the 8-week training sessions, an increase in the isometric plantarflexion strength was found to be greater for the RVT compared with the RT group (p<.05). Muscle inhibition was significantly decreased after training than before training only for the RVT (p<.05). Following the detraining period, a decrease in isometric plantarflexors strength and a increases in muscle inhibition were significantly less in the RVT compared with the RT group. In conclusion, the exercise with WBV is a feasible training modality for the elderly and seems to have a boosting effect when used with conventional resistance training.

• 대한물리의학회지
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• 제3권1호
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• pp.27-37
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• 2008

Purpose : Today, it enjoys a sports and a leisure where the anterior cruciate ligament(ACL) injury patient increase. The knee joint is important means of human body movement and to do an important duty when it encounters ACL injuries of the knee joint and the many restriction follows in the life which is ordinary. When it is damaged ACL, it comes to determinate that ACL reconstruction and preservation treatment that the according to condition of ligament and knee joint. After ACL reconstruction, that is the fact which already becomes known the exercise treatment advances a recovery and to reduce a sequela. Methods : we researched the method of exercise treatment after anterior cruciate ligament reconstruction operation by journal of science direct and KISS in daecu university. Results : The representative exercise treatment is isometric exercise, isokinetic exercise isotonic exercise and complex exercise but what kind of exercise treatment most is effective, it revealed and support it was not. The method of exercise treatment is very various, so It causes a confusion made to the therapist and patients. So it executes once again it sought the kinetic therapeutic method which is efficient from this research and it tried to observe preceding research after ACL reconstruction. To operation a various the exercise treatments, operation only the treatment which is general compared to it was effective in muscular power and muscle functional improvement. But this like improve despite with the exercise treatment consequence which is continuous from research of most the pain leg compares to the health leg, it appeared the discrepancy which is a muscular power, a muscular endurance and a hypertrophy muscle etc, to the health leg or before operating 100% of muscular power to having gets the many therapy time was the recovery rate. Conclusion : Therefore after ACL reconstruction, it will become the many research continuously which is improve the muscle functional and ROM of the exercise treatment method and From therapeutic site of the patients it does to memorizes knowledge in advance about ACL injuries and the application the isokinetic treatment or exercise program are the set of necessary, frequency and amusement that considers complex what kind of therapeutic exercise becomes accomplished with the patient take care of attention.

• 한국전문물리치료학회지
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• 제12권1호
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• pp.1-10
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• 2005

The purpose of this study was to verify the most effective spinal stabilization exercises program by comparing the activities of muscles contributing to spinal stabilization during four types of exercises using a sling and a mat. Twenty healthy males were recruited and each subjects performed four types of exercises. Exercise 1 was performed in a quadruped position with the subjects lifting the left arm and the opposite leg on the mat. Exercise 2 was performed in a prone position while holding a sling with the right hand and the left knee was fully extended while lifting the left arm and right leg. Exercise 3 was performed in quadruped position while holding a sling with one the right hand and lifting the opposite arm and leg. In exercise 4, subjects were instructed to maintain a balance push-up position while holding slings with both hands in 10 cm forward reaching with extended elbows. Electromyographic(EMG) activities were recorded from the multifidus, external oblique, internal oblique, abdominal rectus, and erector spinalis muscles during the exercises. The EMG amplitude of each muscle was normalized to the amplitude in the maximal voluntary isometric contraction (MVIC) of each muscle. Repeated ANOVA and Bonferroni's tests were used to compare the differences in the muscle activity according to the types of exercise. The EMG amplitudes of all the muscles were significantly different according to the types of exercises (p<.05). The highest EMG activities of each muscle was as follow; multifidus was 73.38%MVIC in exercise 3, the erector spinalis was 40.03%MVIC in exercise 3, the external oblique was 135.88%MVIC in exercise 4, the internal oblique was 128.60%MVIC in exercise 4, and the rectus abdominalis was 95.24%MVIC in Exercise 4. The types of exercises showed a significant difference in composition rate of EMG amplitudes of each muscle (p<.05). EMG composition rate of the multifidus was high in exercise 1 and 3. However, EMG composition rates of the external oblique, internal oblique, and the rectus abdominals were high in exercise 2 and 4. These results showed differences in EMG activities of muscles contributing to trunk stabilization during different therapeutic exercises. Therefore, the type of exercise should be carefully selected to effectively strengthen a specific trunk stabilizer.

• 한국운동역학회지
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• 제18권4호
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• pp.21-30
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• 2008

본 연구에서는 신장성 수축운동에 의한 미세 근수축 요소 손강 이론(Morgan & Allen, 1999)을 검증하고자 신장성 수축운동의 범위에 따른 골격근의 기계학적 특성 변화에 주안점을 두어 실험 연구를 수행 하였다. 12명의 건강한 피험자가 최대 발목 족배굴곡근의 신장성 수축운동을 수행하였고, 운동수행 전에 최대 등척성 발목 족배굴곡 모멘트-각도 관계로부터 최적 발목 각도의 변화를 측정하였다. 신장성 수축운동 추 최적 발목 각도 변화는 신장성 수축운동의 범위와 상관없이 근육의 길이가 긴 쪽으로 변화를 가져왔다(4도, p<.05). 따라서 본 연구의 결과는 현재 많은 연구에서 거론되고 있는 신장성 수축에 의한 근력 저하 및 지연성 근육통의 촉발 기전인 신장성 수축에 의한 미세 근수축 요소 손강 이론의 부합하지 않으며, 이 현상을 설명할 새로운 이론 개발을 위한 후속연구의 필요성을 제기한다.

• 한국전문물리치료학회지
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• 제24권4호
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• pp.29-37
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• 2017

Background: The serratus anterior (SA) muscle is one of the important muscles in the upward rotation of the scapula when the arm is raised. Insufficient muscle activity of the SA can cause deformation of the shoulder rhythm resulting in shoulder pathology. Objects: This study intends to compare SA and upper trapezius (UT) activity during the conventional wall-slide and push-up plus exercises for SA muscle strengthening and the scapular upward rotation (SUR) exercise. Methods: A total of 30 subjects participated in this study, and we measured the muscle activity of the SA and UT muscles during the wall-slide, push-up plus and SUR exercises. The one-way repeated ANOVA was used to compare SA and UT muscle activities during the 3 exercises. Results: During the SUR exercise, SA muscle activity was 79.88% maximum voluntary isometric contraction (MVIC), which was significantly higher than its activity during the other 2 exercises. The UT muscle activity was 47.53 %MVIC during the SUR exercise, indicating a significantly higher UT muscle activity than during the other 2 exercises. Conclusion: These findings suggest that the SUR exercise can maximize SA muscle activity to strengthen the SA while keeping UT muscle activity at an appropriate level.

• PNF and Movement
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• 제15권2호
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• pp.167-176
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• 2017

Purpose: This study investigated the effect of core and abdominal muscle-strengthening exercises on muscle activity in the lower extremity on unexpected perturbation. Methods: Twenty subjects were randomly divided into the core exercise group (n=10) or the abdominal muscles strengthening group (n=10). The two groups performed their exercises during three sessions a week for a total of four weeks. The muscle activity in the lower muscles (rectus femoris, biceps femoris, tibialis anterior, gastrocnemius) was assessed using surface electromyography (EMG) and normalized maximal voluntary isometric contraction (MVIC) before and after the exercises. Results: An increase in the tibialis anterior activity after the core and abdominal muscles strengthening exercises was found after four weeks. A significant difference in the pre- and post-exercise was found. The gastrocnemius muscle activity increased in the core exercise group more than the abdominal muscles strengthening group. However, the difference was not significant. Conclusion: The results of this study suggest that the core and abdominal muscles strengthening exercises increased the tibialis anterior muscle activity. It is expected to help make more balance ability that affect who has abdominal muscles weakness.