• Physical Therapy Rehabilitation Science
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• v.8 no.4
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• pp.175-186
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• 2019

Objective: Non-specific chronic low back pain (NS-CLBP) has been related to abnormal trunk muscle activations, but literature reported considerable variability in muscle amplitudes of NS-CLBP patients during prolonged sitting periods. Therefore, the purpose of this study was to examine the differences among homogenous NS-CLBP subgroups in muscle activity, using muscle co-contraction indices as a more objective approach, and their roles on pain development during a 1-hour period of prolonged sitting. Design: Cross-sectional study. Methods: Twenty NS-CLBP subjects with motor control impairment (MCI) [10 classified as having flexion pattern disorder, and 10 with active extension pattern disorder], and 10 healthy controls participated in the study. Subjects followed a 1-hour sitting protocol on a standard office chair. Four trunk muscle activities including amplitudes and co-contraction indices were recorded using electromyography over the 1-hour period. Perceived back pain intensity was recorded using a numeric pain rating scale every 10 minutes throughout the sitting period. Results: All study groups presented with no significantly distinctive trunk muscle activities at the beginning of sitting, nor did they change over time when pain increased to a significant level. Both MCI subgroups reported a similarly significant increase in pain behavior through mid-sitting (p<0.001). However, after mid-sitting, they significantly differed from each other in pain (p<0.01) but did not differ in the levels of muscle activation. Conclusions: This study was the first to highlight the similarities in trunk muscle activities among homogenous NS-CLBP patients related to MCI and compared them to healthy controls while sitting for an extended period of time, and the significant increase in pain over the 1-hour sitting might not be attributed to trunk muscle activation.

• The Journal of Korean Physical Therapy
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• v.35 no.1
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• pp.13-18
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• 2023

Purpose: The purpose of this study was to investigate the effects of posterior oblique sling activation on the muscle activities of the gluteus maximus (GM), multifidus (MF), and biceps femoris (BF) during three different prone hip extension exercises in healthy male individuals. Methods: Twenty healthy subjects participated in this study. An electromyography device was used to measure the muscle activities of the GM, MF, and BF. Each subject was asked to perform three different prone hip extensions as follows: [1) Prone hip extension with knee flexion + hip abduction 30°; PHE1, 2) Prone hip extension with knee flexion + hip abduction 30° and shoulder abduction 125°; PHE2, 3) Prone hip extension with knee flexion + hip abduction 30° and shoulder abduction 125° with 1kg loading; PHE3, in random order. A one-way repeated measures analysis of the variance and a Bonferroni post hoc test were used to analyze the results. The statistical significance was set at α=0.01. Results: The muscle activity of the GM was significantly different between the three positions (P_adj<0.01). The muscle activity of the GM was significantly greater during PHE3 compared with PHE1 and PHE2 (P_adj<0.01). The BF muscle activity was significantly lower during PHE3 compared with PHE1 and PHE2 (P_adj< 0.01). There was no significant difference in the muscle activity of the MF (P_adj<0.01). The ratio of the muscle activity (ratio=GM/BF) during PHE3 was significantly greater compared to PHE1 and PHE2 (P_adj< 0.01). Conclusion: The GM activity and GM/BF ratio during the PHE3 exercise were significantly greater compared to that during PHE1 and PHE2. Therefore, the PHE3 exercise could be recommended as a selectively effective GM activation exercise while decreasing the muscle activity of the BF.

• Physical Therapy Korea
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• v.19 no.3
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• pp.11-19
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• 2012

This study aimed to investigate whether isometric lower limb exercise can activate contralateral trunk muscles and whether the magnitude of muscle activation is related to lower limb movement in sitting. This study included 25 healthy young subjects (20 males and 5 females). The magnitude of trunk muscle activation was measured using surface electromyography (EMG) during hip flexion, extension, adduction, and abduction, and a significant difference was observed in the activation levels of trunk muscles among the tests (p<.01). The EMG activity of the multifidus (MF) and erector spinae (ES) muscles on the contralateral side were significantly greater during hip extension. However, the activation levels of the contralateral internal oblique (IO) and rectus abdominis (RA) muscles were greatest during hip flexion. The MF : ES EMG ratio was significantly greater during hip isometric during hip isometric flexion and abduction compared to hip extension and adduction. There was no significantly difference in the IO : RA ratio during the isometric contractions toward different directions. These findings indicate that isometric lower limb exercise can elicit trunk muscle contraction on the contralateral side and may therefore be helped for developing contralateral trunk muscle strength in individuals undergoing rehabilitation.

• Physical Therapy Korea
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• v.24 no.4
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• pp.11-19
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• 2017

Background: Methods for exercising serratus anterior (SA) and upper trapezius (UT) muscles are important for the recovery of patients with various shoulder disorders, yet the efficacy of closed or open kinetic chain exercises have not yet been evaluated. Objects: The purpose of this study was to compare the activation of the SA and UT muscles during scapular protraction considering both closed and open kinetic chain exercises. Methods: Thirty subjects were randomly divided into experimental groups (closed kinetic chain exercise) and control groups (open kinetic chain exercise) in which scapular protraction was performed at $90^{\circ}$ or $125^{\circ}$ shoulder flexion. Electromyographic activity data were collected from the SA and UT muscles per position and exercise method. Results: Separate mixed 2-way analysis of variance showed significant differences in the activation of the SA (F1,28=6.447, p=.017) and the UT (F1,28=35.450, p=.001) muscles between the groups at $90^{\circ}$ and $125^{\circ}$ shoulder flexion. Also, the SA/UT ratio measures at $90^{\circ}$ and $125^{\circ}$ shoulder flexion significantly differed between the groups (F1,28=15.457, p=.001). That is, the closed chain exercise was more effective than open chain exercise for strengthening the SA muscle and controlling the UT muscle, $125^{\circ}$ of shoulder joint was more effective than $90^{\circ}$. Conclusion: The findings suggest that scapular protraction with shoulder $125^{\circ}$ flexion at the closed kinetic chain exercise may be more effective in increasing SA muscle activation and decreasing UT muscle activation as well as increasing the SA/UT ratio than open kinetic chain exercise.

• Journal of the Korea Convergence Society
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• v.11 no.5
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• pp.73-80
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• 2020

The purpose of this study was to investigate the immediate effects of kinesio taping on upper extremity pain and muscle activation of lateral epicondyle DOMS. This research is randomized controlled designd study and conducted as a single-blind. Twenty four subjects were participated in this study, All the patients were divided two group, were kinesio taping applied group, placebo kinesio taping applied group. The participants were tested pressure upper extremity pain threshold and muscle activation, pre-post intervention. After raining, the change values of the pain and muscle activation in KT group were significantly greater than PKT group(p<0.05). This findings show that kinesio taping training convergence interventions for lateral epicondyle DOMS pain and upper extremity. Continued development on convergence interventions for lateral epicondyle DOMS with pain and upper extremity in the practice are suggested.

• Korean Journal of Applied Biomechanics
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• v.16 no.3
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• pp.75-83
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• 2006

The purpose of this study was to investigate steady-state force depression following active muscle shortening in human tibialis anterior muscle during voluntary contractions. Subjects (n = 7; age $24{\sim}39$ years; 7 males) performed isometric reference contractions and isometric-shortening-isometric contractions, using maximal voluntary effort. Force depression was assessed by comparing the steady-state isometric torque produced following active muscle shortening with the purely isometric reference torque obtained at the corresponding joint angle. In order to test for effects of the shortening conditions on the steady-state force depression, the speed of shortening were changed systematically in a random order but balanced design. Ankle dorsiflexion torque and joint angle were continuously measured using a dynamometer. During voluntary contractions, muscle activation of the tibialis anterior and the medical gastrocnemius was recorded using surface electromyography. Force depression during voluntary contractions, with a constant level of muscle activation, was 12 %, on average over all subjects. Force depression was independent of the speeds of shortening ($13.8{\pm}2.9%$, $10.3{\pm}2.6%$ for 15 and 45 deg/sec over 15 deg of shortening, respectively). The results of this study suggest that steady-state force depression is a basic property of voluntarily-contracting human skeletal muscle and has functional implication to human movements.

• The Journal of Korean Physical Therapy
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• v.34 no.1
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• pp.6-11
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• 2022

Purpose: This study investigated the muscle activity of the lower trapezius (LT) during three different shoulder flexion exercises. Methods: Twenty-three subjects between 20 and 25 years of age were enrolled. The subjects were asked to perform three different shoulder flexion exercises: 1) shoulder flexion in prone (SFP), 2) shoulder flexion in push-up with a swiss ball (SFPUS) and 3) shoulder flexion in a quadruped position with a swiss ball (SFQPS) in random order. The muscle activity of LT during each shoulder flexion exercise was measured by using surface electromyography. The muscle activity of LT was compared using one-way analysis of variance (ANOVA) and Bonferroni post hoc test among three different shoulder flexion exercises. The statistical significance level was set at α=0.01. Results: The muscle activity of LT was significantly different among three different shoulder flexion exercises (SFP, SFPUS, and SFQPS). The LT muscle activity with SFQPS exercise was greater than SFP and SFPUS exercises (p<0.01). There was no significant difference in LT muscle activity between SFP and SFPUS exercises (p>0.01). Conclusion: The LT muscle activity was greater during SFQPS than SFP and SFPUS. Therefore, SFQPS exercise can be recommended for selectively activation of LT muscle.

• Korean Journal of Applied Biomechanics
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• v.25 no.2
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• pp.219-229
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• 2015

Objective : The purpose of this study was to analyze EMG according to surface type and elastic band usage during the pilates Superman movement. Method : The subjects were 10 female university students with a mean age of 27. The independent variables were surface type (yoga mat, air filled equipment, elastic mat) and elastic band usage. In order to measure muscle activity, the Noraxon(USA) was used. Eight muscles (upper trapezius, lower trapezius, thoracic spine, lumbar spine, gluteus maximus, gluteus medius, biceps femoris, semitendinosus) activation were analyzed. For the statistical analysis, MANOVA, independent t-test and Scheffe test for the post-hoc via SPSS 20.0 was used. Results : The left and right upper trapezius muscle activities were significantly reduced when using the elastic bands. In addition gluteus medius muscle activities significantly increased with the elastic band as well. Conclusion : According to the usage of the elastic band and the different types of surfaces, different muscle groups were recruited. Elastic bands were found to have more activation on the gluteus medius muscle meanwhile there was less activation on the upper trapezius during the pilates Superman movement.

• PNF and Movement
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• v.15 no.3
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• pp.217-226
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• 2017

Purpose: The purpose of this study was to determine the effects of a modified abdominal draw-in maneuver on trunk stability and functional capacity as well as pain in patients with chronic low back pain. Methods: The study included 3 patients with chronic low back pain who volunteered to participate. The modified abdominal draw-in maneuver included a posterior pelvic tilt, a traditional abdominal draw-in maneuver, and a vibration sensory feedback device. Voluntary abdominal contraction using the vibration sensory feedback device was performed by the subjects for more than 1 hour per day, 5 times per week, for 6 weeks along with common low back pain treatment. Electromyographic signals in the rectus abdominis (RA), external oblique (EO), internal oblique (IO), and erector spinae (ES) muscles were measured to compare muscle activation. The degree of pain was measured using the visual analogue scale (VAS), and functional capacity was measured using the Korea Oswestry Disability Index (K-ODI). All results were compared to the means before and after intervention. Results: After the intervention, the RA, EO, and IO showed increased muscle activation and the ES showed decreased muscle activation. The visual analogue scale decreased after intervention and the K-ODI decreased after intervention. Conclusion: Modified abdominal draw-in maneuvers in daily life combined with therapeutic exercises may be effective in relieving pain and dysfunctions in chronic low back pain patients.

• Journal of The Korean Society of Integrative Medicine
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• v.3 no.1
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• pp.71-80
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• 2015

Purpose: The purpose of this study was to compared the muscle activities of vastus medialis, vastus lateralis, rectus femoris in open kinetic chain and closed kinetic chain. Methods: Subjects of the study were 30 adults students. They were divided into 2 group, one for open kinetic chain and other for closed kinetic chain of extension, flexion, the maximum extension for vastus medialis, vastus latarealis, rectus femoris muscle activation. Results: Rectus femoris increased open kinetic chain group about all posture and vastus medialis increased open kinetic chain group about the maximum extension and flexion. and vastus lateralis increased open kinetic chain group about the maximum extension and flexion. Conclusion: Muscle activation are at the highest with the open kinetic chain in vastus medialis, vastus lateralis, rectus femoris. probably steady exercise thinked for open kinetic chain and closed kinetic chain.