• Korean Journal of Applied Biomechanics
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• v.27 no.1
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• pp.35-43
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• 2017

Objective: The purpose of this study was to determine how gaze angle affects muscle activity and kinematic variables during treadmill walking and to offer scientific information for effective and safe treadmill training environment. Method: Ten male subjects who have no musculoskeletal disorder were recruited. Eight pairs of surface electrodes were attached to the right side of the body to monitor the upper trapezius (UT), rectus abdominis (RA), erector spinae (ES), rectus femoris (RF), bicep femoris (BF), tibialis anterior (TA), medialis gastrocnemius (MG), and lateral gastrocnemius (LG). Two digital camcorders were used to obtain 3-D kinematics of the lower extremity. Each subject walked on a treadmill with a TV monitor at three different heights (eye level; EL, 20% above eye level; AE, 20% below eye level; BE) at speed of 5.0 km/h. For each trial being analyzed, five critical instants and four phases were identified from the video recording. For each dependent variable, one-way ANOVA with repeated measures was used to determine whether there were significant differences among three different conditions (p<.05). When a significant difference was found, post hoc analyses were performed using the contrast procedure. Results: This study found that average and peak IEMG values for EL were generally smaller than the corresponding values for AE and BE but the differences were not statically significant. There were also no significant changes in kinematic variables among three different gaze angles. Conclusion: Based on the results of this study, gaze angle does not affect muscle activity and kinematic variables during treadmill walking. However, it is interesting to note that walking with BE may increase the muscle activity of the trapezius and the lower extremity. Moreover, it may hinder proper dorsiflexion during landing phase. Thus, it seems to reasonable to suggest that inappropriate gaze angle should be avoided in treadmill walking. It is obvious that increased walking speed may cause a significant changes in biomechanical parameters used in this study. It is recommended that future studies be conducted which are similar to the present investigation but using different walking speed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.11
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• pp.5689-5697
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• 2013

The purpose of this study was to determine the effects of scapular taping on muscle activities of the scapular rotators and anterior deltoid, ROM, shoulder pain, proprioception in subacute stroke patients. Twenty-eight patients were randomly assigned to an experimental and control groups of fourteen patients respectively. Muscle activity of upper and lower trapezius, serratus anterior, anterior deltoid was measured using surface electromyography. Visual analog scale was used for shoulder pain. Electro-Goniometry was used for shoulder elevation ROM. Assessment board was used for shoulder elevation proprioception. The muscle activity of the lower trapezius and serratus anterior increased significantly after scapular tape application (p<0.05). The AROM and PROM in the shoulder elevation significantly increased after scapular tape application (p<0.05). The VAS in the shoulder no significantly decreased after scapular tape application (p>0.05). The proprioception in the shoulder no significantly increased after scapular tape application (p>0.05). The results of this study suggest that scapular taping can be used an additional therapy for increasing muscle activity of lower trapezius and serratus anterior and ROM during shoulder elevation in subacute stroke patients.

• PNF and Movement
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• v.21 no.1
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• pp.87-94
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• 2023

Purpose: The present study aims to investigate the effects of a diagonal exercise pattern on selective activation of the upper extremity muscles using both normalization and isolation methods. Methods: In total, 17 asymptomatic subjects participated in this study. During the two diagonal patterns of exercise (diagonals 1 and 2), muscular activities of the upper trapezius (UT), lower trapezius (LT), serratus anterior (SA), anterior deltoid (AD), and infraspinatus (IS) were measured. The collected data were analyzed in two ways, according to the dominance of muscle activities (%Isolation) and according to normalized activities (%MVIC). Results: There were significant differences in LT, SA, AD, and IS between %MVIC and %Isolation (p<0.05), and the diagonal 1 pattern of exercise showed significantly more LT activities compared with the diagonal 2 pattern (p<0.05). Further, except for LT, there were no significant differences in muscle activities between the diagonal 1 and 2 exercises. Conclusion: The present study suggests that a diagonal pattern of exercise is advantageous for strengthening shoulder muscles, but caution is needed when applying to patients requiring selective strengthening. Regarding both the concentric and eccentric phases of exercise, there was no significant difference in muscular activation, except in LT, between the two diagonal patterns of exercises.

• The Journal of Korean Physical Therapy
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• v.26 no.6
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• pp.379-385
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• 2014

Purpose: This study was to determine the immediate effects of pulsed magnetic field (PMF) in subjects with upper trapezius (UT) trigger point (TrP). Methods: Fifteen subjects with UT TrP were recruited for the study's PMF group (pain threshold=$2.29kg/cm^2$), and 15 age-, weight-, and gender-matched subjects with UT TrP were recruited for control group (pain threshold=$2.25kg/cm^2$). Pressure algometer was used to measure pressure pain threshold on UT TrP and, cervical range of motion (ROM) inclinometer was used to measure cervical ROM. Surface electromyography was used to record UT, lower trapezius, and serratus anterior muscle activity and relative ratio during scapular plane abduction between pre- and post-treatment. Results: The PMF effectively improved pain threshold and concurrently increased ROM (rotation to the painful side, lateral flexion to the nonpainful side). In addition, the PMF may effectively deactivate UT activity during abduction and the muscle activity ratio between UT and serratus anterior. Conclusion: These findings provided empirical evidence that PMF can be an effective treatment method to reduce pain threshold, to increase cervical ROM, and deactivate UT activity in individuals with TrP.

• Physical Therapy Korea
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• v.24 no.1
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• pp.61-70
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• 2017

Background: Scapular winging is a prominence of the entire scapular medial border, mainly caused by insufficient activity of the serratus anterior (SA) and imbalance of scapulothoracic muscles. Push-up plus (PUP) exercise has been commonly used to increase SA muscle activity. The facilitation of abdominal muscle may affect scapular muscle activity by myofascial connections. Thus, the sequential activation of the turnk muscles is suggested to facilitate the transition of proper force from upper limb and restore force couple of scapular muscles. The abdominal drawing-in maneuver (ADIM) has been effective in improving activation of the deep trunk muscles during movement. Objects: The aim of this study was to determine the effect of ADIM on the activity of the upper trapezius (UT), lower trapezius (LT), and SA during PUP exercises in subjects with scapular winging. Methods: Fourteen men with scapular winging (determined as a of distance between the scapular medial border and thoracic wall over 3 cm) volunteered for our study. The subjects performed the PUP exercise with and without ADIM. Surface electromyography was used to collect the electromyography data of the UT, LT, and SA. A scapulometer was used to measure the amount of scapular winging. Results: SA activity was significantly greater and scapular winging significantly lower during the PUP exercise with ADIM than during those without ADIM. Conclusion: PUP exercise with ADIM can be used as an beneficial method to improve SA activation and to reduce the amount of scapular winging in subjects with scapular winging.

• Journal of the Korea Convergence Society
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• v.9 no.2
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• pp.341-347
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• 2018

The purpose of this study is to examine the change to the muscle activity from the serratus anterior(SA) of 5th and 7th, upper trapezius(UT), middle trapezius(MT) lower trapezius (LT), and pectoralis major(PM) when push-up plus exercise(PUP) is performed in four postures. 25 healthy, young participants performed various PUP convergence exercise(general posture, $90^{\circ}$, $120^{\circ}$ and BOSU). The muscle activity of the shoulder stability muscles was measured using a surface EMG analysis system during various PUP convergence exercise. One-way repeated-measure of ANOVA was conducted to comparison the activity of each muscle. There was significant difference in SA7, PM, UT, and MT (p <.05) during various PUP. The muscle activity of SA7 had a significance difference between PUP and $90^{\circ}PUP$ or BOSUPUP respectively (p <.05). The muscle activity of PM had a significance difference between $90^{\circ}PUP$ and PUP or BOSUPUP (p <.05). The muscle activity of UT had a significance differnce between $90^{\circ}PUP$ and PUP or BOSUPUP (p <.05). The muscle activity of MT had a significance differnce between $90^{\circ}PUP$ and PUP and also significantly difference PUP and $120^{\circ}PUP$(p <.05). These results suggest that general PUP can be a useful to improve to scapular stabilizer muscle in who has no shoulder dysfunction.

• The Journal of Korean Physical Therapy
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• v.28 no.2
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• pp.106-111
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• 2016

Purpose: The aim of this study is to determine the effect of glenohumeral (GH) rotation position in modified knee push-up plus exercise (MKPUP) by examining the surface electromyography (EMG) amplitude in serratus anterior (SA), pectoralis major (PM), and upper trapezius (UTz) and the activity ratio of each muscle. Methods: A total of 22 healthy subjects volunteered for the study. Each subject performed the MKPUP at $0^{\circ}$, $45^{\circ}$, and $90^{\circ}$ of GH joint internal rotation. EMG of the SA and PM, UTz was compared between GH rotation positions and each muscle activity ratio. EMG was used to measure the muscle activity in terms of ratios to maximal voluntary isometric contraction (MVIC). Results: The difference in EMG activity during the exercise in three GH joint internal rotation positions was observed with the SA and the PM. The greater the GH joint internal rotation angle was, the lower the activity of the PM. In contrast, the SA showed higher activity. However, the activity of UT was similar under all conditions. The ratio of the SA and the PM was considerably greater at $90^{\circ}$ GH joint internal rotation than at $0^{\circ}$ and $45^{\circ}$. Conclusion: When excessive activation of the PM or imbalanced activation between the PM and the SA occurs, the MKPUP exercise is most effective at $90^{\circ}$ of GH joint internal rotation. Use of this position would be a beneficial strategy for selective strengthening of the SA and minimizing PM activation.

• The Journal of Korean Physical Therapy
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• v.22 no.5
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• pp.9-16
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• 2010

Purpose: The purpose of this study was to compare modified sling exercise and general isometric exercise in patients with shoulder impingement syndrome. Methods: Twenty subjects were studied. The control group, n1 = 10, received instructions for doing general isometric (ISO) exercise. An experimental group, n2 = 10, received instructions for doing push-ups from standing and sitting positions and modified scapular exercises using a sling (3 sets, 3 times per week for 6 weeks). To evaluate the effects of exercise, subjects were evaluated using a visual analog scale for pain, a goniometer for range of motion, and electromyography for onset time of muscle contraction. Statistical analysis was done using the Wilcoxon Signed rank and Mann-Whitney U tests. Results: Pain in the sling group was significantly decreased after 6 weeks of treatment (p<0.05) pain in the general ISO exercise group was not significantly decreased (p>0.05). Flexion and external rotation were significantly increased after 6 weeks of treatment in both groups (p<0.05) and the change in the Sling group was greater than in the ISO group (p<0.05) in the flexion test. Time of onset of contractions in the Sling group for the upper trapezius, lower trapezius and serratus muscle were significantly decreased after 6 weeks of treatment (p<0.05), but the onset time for the middle trapezius did not significantly decrease (p>0.05). Conclusion: Scapular stabilizing exercise using a sling increases range of motion and decreases pain, and onset time of muscle contraction in patients with impingement syndrome.

• Physical Therapy Korea
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• v.21 no.2
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• pp.48-56
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• 2014

The aim of this study to investigate the effects of craniocervical flexion on muscle activities of scapular upward rotators during push-up plus exercise in subjects with winging scapula. Eighteen males with scapular winging were recruited, and each subject performed knee push-up plus and other exercises, in two conditions (craniocervical flexion vs. natural head positions). A surface electromyography (EMG) was used to measure upper trapezius (UT), serratus anterior (SA), and lower trapezius (LT) muscle activity. A paired t-test was used to determine the statistical significance between the different condition with/without applying of craniocervical flexion. UT EMG activity significantly decreased and SA EMG activity significantly increased during knee push-up plus involving the craniocervical flexion compared to the natural head position. However, no significant differences (p>.05) were found in the activity of the LT muscle. The UT/SA ratios with and without craniocervical flexion showed a significant difference (p<.05). These results showed that the knee push-up plus other exercises performed with craniocervical flexion could strengthen the serratus anterior muscle and minimize the activity of the UT muscle.

• The Journal of Korean Physical Therapy
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• v.32 no.1
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• pp.58-63
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• 2020

Purpose: This study examined the effects of the right or left knee lift during push up plus in the quadruped position on the serratus anterior (SA) muscle activity. Methods: Twenty-one subjects (male 11, female 10) performed the quadruped position on push up plus. The muscle activities of the lower trapezius (LT), SA, and upper trapezius (UT) were measured by surface electromyography. Repeated measurements of one-way ANOVA were performed for statistical analysis of the data, and the criterion for statistical significance was set to p<0.05 and comparative analysis of the UT and SA ratio using a Paired t-test. Results: The right SA increased the muscle activity of the right knee lift during quadruped position push up plus (p<0.05). In particular, the right SA muscle activity was higher than the left. In addition, comparative analysis of the UT and SA ratio to the right knee lift during quadruped position push up plus was performed (p<0.05). The right was found to be a significant statistic compared to the left, but the left SA increased the muscle activity of the left knee lift during quadruped position push up plus (p<0.05). The left SA muscle activity was higher than right. In addition, comparative analysis of UT and SA ratio to the left knee lift during quadruped position push up plus was performed (p<0.05). The left was found to be a significance statistic than the right. In addition, the interaction effect between the groups showed significant differences (p<0.05). Conclusion: Knee lift during push up plus is recommended for the selective activation of a research exercise protocol of one side of the serratus anterior.