• Journal of The Korean Society of Integrative Medicine
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• v.1 no.4
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• pp.85-92
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• 2013

PURPOSE : The purpose of this study was to determine the effects of the length of the pectoralis minor on muscle activity of trapezius and pectoralis major in subjects in subjects with shortened pectoralis minor muscle. METHOD : The subjects was participated in 36 with shortened pectoralis minor muscle. All subjects was examined the length test of pectoralis minor muscle. we divided by 3 groups. group I(n=12) was for 4~5cm of length of pectoralis minor muscle, group II(n=12) was for 5~6cm, group III(n=12) was for above 6cm. The EMG activity of upper trapezius, middle trapezius, lower trapezius and pectoralis major muscle activity was measured by surface EMG while elevationg the right arm in sitting postion with head to the neutral, shoulder elevation $135^{\circ}$ with scaption. Data were analyed using one-way ANOVA with a Tukey post hoc test. RESULT : The EMG activity differed significantly among the three groups(p<.05). The group III had significantly greater EMG activity of upper trapezius and pectoralis major muscles than group I and II(p<.05). Also, The group III had significantly smaller EMG activity of lower trapezius muscle than group I and II(p<.05). But, these was no significant difference in the EMG activity of the middle trapezius muscle among the groups (p.05). CONCLUSION : Therefore, the result of this study should be suggested that the shortened pectoralis minor muscle was affected the EMG activity of the upper trapezius, lower trapezius and pectoralis major. Ultimately the length of the pectoralis minor muscle leads to the muscle imbalance in shoulder girdle.

• Journal of the Korean Society of Physical Medicine
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• v.14 no.4
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• pp.81-91
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• 2019

PURPOSE: This study examined the effects of Kinesiology taping followed by pectoralis minor muscle self-stretching on the rounded shoulder posture, neck range of motion, and upper trapezius muscle tone in subjects with a rounded shoulder posture. METHODS: Thirty adults with a rounded shoulder posture were assigned randomly to one of two groups, either one that only performed pectoralis minor muscle self-stretching or a group that performed pectoralis minor muscle self-stretching after applying Kinesiology taping ; the subjects underwent four weeks of intervention. Three rounds of intervention were carried out over four weeks, and before and after the experiment, rounded shoulder posture, neck range of motion, and upper trapezius muscle tone creep were measured. RESULTS: Following the interventions, both the experimental and control groups showed significant improvement in the rounded shoulder posture, neck range of motion, upper trapezius muscle tone, stiffness, relaxation, and creep. Significant differences in the post training gains in the rounded shoulder posture and neck range of motion were observed between the experimental and control groups. CONCLUSION: These results showed that a combination of Kinesiology taping and pectoralis minor muscle self-s tretching led to more significant improvement than that seen when only utilizing the application of pectoralis minor muscle self-stretching to change the posture of the subjects with a rounded shoulder posture.

• Journal of The Korean Society of Integrative Medicine
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• v.5 no.3
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• pp.21-28
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• 2017

Purpose: The purpose of this study was to investigate the effects of three exercise programs on forward head posture. Methods: Ninety-five individuals were recruited to assess the of the pectoralis minor muscle. Of these, 36 individuals with pectoralis minor muscles were selected and randomly divided into three groups: a functional massage group, a stretching group, and a stretching and muscle strengthening group. The exercise program consisted of sessions four times per week for two weeks. The length of pectoralis minor and the activity of the trapezius muscles were measured using electromyography. Forward head posture was assessed using the craniovertebral angle (CVA) and the cranial rotation angle (CRA) pre-, during and post-treatment. Result: Significant improvements were observed in pectoralis minor length, CRA, and CVA post-treatment in all groups (p<0.05, p<0.01, p<0.001). However, only the activity of the lower trapezius demonstrated a statistically significant difference post-treatment. There were no significant differences between the groups. Conclusion: The findings of this study suggest that all three exercise programs were effective in improving forward head posture and the length of pectoralis minor post-treatment.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.30 no.2
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• pp.1-12
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• 2024

Background: This study aimed to determine the effects of pectoralis minor stretching, lower trapezius strengthening exercise with serratus anterior strengthening exercise to find an effective therapeutic exercise for alignment, shoulder range of motion, muscle imbalance of rounded shoulder patient. Methods: This study targeted on a total of 28 male subjects, aged 20s and 30s, and randomly divided the subjects into each group, with 14 subjects each. The experimental group performed pectoralis minor stretching, lower trapezius strengthening exercise, and serratus anterior strengthening exercise, while the control group performed pectoralis minor stretching and lower trapezius strengthening exercise. Results: both group showed an increase in active range of motion for shoulder flexion, a muscle activity of the serratus anterior muscle and the lower trapezius muscle, a decrease in muscle activity of the upper trapezius muscle, and a significant improvement in scapular alignment after the intervention. In the comparison between group, the experimental group showed greater increased shoulder joint flexion range of motion, serratus anterior muscle activity, and decreased upper trapezius muscle activity than the control group. Conclusion: Performing serratus anterior strengthening exercises with pectoralis minor stretching and lower trapezius strengthening exercises is effective for improving the active range of motion in shoulder joint flexion and muscle imbalance

• Physical Therapy Korea
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• v.19 no.2
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• pp.12-19
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• 2012

The purpose of this study was to assess the influence of scapular alignment on the electromyographic (EMG) activity of the trapezius in people with a short pectoralis minor muscle. For the study, we recruited 15 volunteers who had positive results for short on a pectoralis minor muscle length test. We measured the EMG activity of the upper, middle and lower trapezius muscles. The participants lifted their dominant arm to ear level with the thumb up toward the ceiling in the prone position on a table with the shoulder at a flexion angle of 180 degrees and a horizontal abduction angle of 120 degrees. Scapula was manually aligned by an experienced physical therapist prior to arm lift for the scapular alignment condition. A paired t-test was used to compare the effects of scapular alignment on the EMG activity of the trapezius muscles. The EMG activity of the lower trapezius muscle was significantly increased during the test with the scapular alignment compared to that without scapular alignment (p<.05), while the upper trapezius and middle trapezius exhibited no significant difference between the two conditions (p>.05). The findings of this study suggest that a scapular alignment may alter the recruitment of the lower trapezius muscle during arm lifting in the prone position in people with a short pectoralis minor muscle.

• Anatomy and Cell Biology
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• v.55 no.4
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• pp.406-413
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• 2022

The pectoralis minor (PMn) muscle originates from the third, fourth, and fifth ribs near the costochondral junctionusually and gets inserted on the medial margin and upper surface of the coracoid process of the scapula. To look at the morphological insertion patterns and sites of attachment of the PMn muscle in the donated cadavers. Over all 19 limbs were included in the study (9 right and 10 left). Out of 19 limbs, 10 belonged to female and 9 belonged to male cadavers. The cadavers were meticulously dissected to determine the morphological insertion types and location of the attachment of the muscle. Unusual pattern of insertion was observed in 6 limbs (31.6%) out of total 19 limbs included in the study. The variations we observed does not fall completely in the classification by Le Double, hence variations we observed can be considered as new and rare variant which to our knowledge is not reported in literature. We propose this new variant to be type 4 of Le Double classification. The potential of ectopic PMn tendon should be taken into consideration and tested out, especially in patients with shoulder discomfort and stiffening who have ruled out the more frequent diseases. For proper surgical planning, a preoperative magnetic resonance imaging or USG examination of the shoulder joint is required considering the prevalence of variation in the insertion pattern of PMn muscle. Preoperative identification of any abnormal PMn insertion can help to reduce the risk of iatrogenic tendon injury and post-operative problems.

• Journal of the Korea Convergence Society
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• v.9 no.1
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• pp.111-116
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• 2018

The aim of this study was to determine the effects of tote bag weight on muscle thickness of pectroalis minor and tone of upper trapezius in young adult women. 27 women habitual of carrying tote bags. The subjects were measured the tone of the upper trapezius muscle and the thickness of the pectoralis minor muscle while carrying tote bags with the weight of 0%, 5%, 7.5% and 10% of the subjects' body weight. As the weight load increased, the upper trapezius muscle demonstrated significantly increased muscle tone (p<.05). additionally, a significantly increased thickness in the pectoralis minor muscle was noted(p<.05). These findings suggest that the habit of carrying a tote bag on the wrist may be disadvantageous to improving the two muscles in young women. Therefore, this study recommend women who likely used tote bag decrease the weight of the bag.

• Physical Therapy Korea
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• v.24 no.2
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• pp.48-57
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• 2017

Background: Rounded shoulder posture (RSP), a postural abnormality, might cause shoulder pain and pathologic conditions. Although most previous research has investigated RSP focusing on the proximal structures of the shoulder, such as the scapula and pectoralis muscles, the relationship between RSP and anterior distal structures of the upper extremity, such as the biceps brachii muscle and elbow joint, is not clearly understood. Objects: This study aimed to investigate the correlations between RSP and the biceps brachii length, elbow joint angle (EJA), pectoralis minor length, general pectoralis major length, humeral head anterior translation (HHAT), glenohumeral internal rotation (IR), external rotation (ER), and horizontal adduction (HAD). Methods: Twelve subjects with RSP (6 male, 6 female) were recruited. All subjects fulfilled the RSP criteria indicated by a distance ${\geq}2.5cm$ from the posterior aspect of the acromion to the table in the supine position. The examiner measured each of the following parameters twice: RSP, biceps brachii length, EJA, pectoralis minor length, pectoralis major length, HHAT, glenohumeral IR, ER, and HAD. Pearson's correlation coefficient(r) was used to assess the correlation between RSP and all the variables. Results: There was a significant moderate positive correlation between RSP and biceps brachii length (r=.55, p=.032), moderate negative correlation between RSP and pectoralis minor length (r=-.62, p=.015), and moderate positive correlation between RSP and HHAT (r=.53, p=.038). Conclusion: The biceps brachii length, pectoralis minor length, and HHAT could be used to evaluate patients with RSP. Better understanding of the correlation between these factors and RSP could help in the development of effective methods to treat patients with this condition in clinical management.

• Journal of the Korean Society of Physical Medicine
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• v.16 no.2
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• pp.45-52
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• 2021

PURPOSE: This study examined the imaging procedure of pectoralis minor muscle thickness and assessed the intra- and inter-rater reliability of the muscle thickness measured by two raters using rehabilitative ultrasound imaging (RUSI) in healthy individuals. METHODS: Fifteen participants (aged 21 - 28, seven females, and eight males) were involved in the study. The primary rater palpated the coracoid process and the fourth rib, defined as the width of the index finger lateral to the sternum to avoid breast tissues, and lined the two landmarks. The second examiner checked 1 / 3 (1st point) and 1 / 2 (2nd point) of the line length as measurement points. The two raters obtained right side muscle images of the participants at a standardized sitting position using RUSI with a 7.5 MHz linear transducer at 40mm depth. For intra-rater reliability, the principal rater took three images per point and tried to take one more with an interval. For the inter-rater reliability, the other rater performed the same tasks as the principal rater on the same day. The reliability was analyzed using the intra-class correlation coefficient (ICC), the standard error of the measurement (SEM), and Bland and Altman plots. RESULTS: The reliability at all points was excellent for the same rater (ICC_3,1 = .973 - .978, SEM = .042 - .046), and between raters (ICC_2,1 = .939 - .959, SEM = .059 - .097). CONCLUSION: These findings show that the RUSI could be reliable for examining the pectoralis minor muscle thickness in healthy individuals at all measurement sites.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.27 no.2
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• pp.17-25
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• 2021

Background: The purpose of this study is to investigate basic data about the effects of muscle energy technique on the shoulder complex range of motion and posture alignment in the round shoulder posture. Methods: The subjects included 15 women that gave consent to participate in the study voluntarily. They performed the muscle energy technique for 30 minutes twice. The round shoulder posture was measured with a straight edge ruler. The shoulder complex range of motion was measured with the apley scratch test. The forward head posture was measured with ImageJ. The pectoralis minor muscle length was measured with a tape measure. Results: There were statistically significant differences in the round shoulder posture both right and left (p<.05). The experiment group showed statistically significant differences in the pectoralis minor muscle length (p<.05). There were significant differences in the shoulder complex range of motion including flexion, left lateral flexion, right lateral flexion, left side bending, and right side bending (p<.05), but no significant differences were found in extension (p>.05). The forward head posture showed significant differences in CVA changes (p<.05) and no significant differences in CRA changes (p>.05). Conclusion: These findings demonstrate that the muscle energy technique relaxed muscles around the shoulders and increased the shoulder complex range of motion. The technique is also expected to prevent pain in the neck and shoulders and lower injury risk. In conclusion, the muscle energy technique can be applied as an effective intervention for round shoulder posture.