• Physical Therapy Korea
• /
• v.24 no.4
• /
• pp.60-67
• /
• 2017

Background: Scapular downward rotation syndrome (SDRS) is a common scapular alignment impairment that causes insufficient upward rotation and muscle imbalance, shortened levator scapulae (LS) and rhomboid, and lengthened serratus anterior (SA) and trapezius. A modified shrug exercise (MSE), performing a shrug exercise with the shoulders at $150^{\circ}$ abduction, is known as an effective exercise to increase scapular stabilizer muscle activation. Previous studies revealed that scapular exercise are more effective when combined with trunk stabilization exercises in decreasing scapular winging and increasing scapular stabilizer muscle activation. Objects: The purpose of our study was to clarify the effect of MSE with or without trunk stabilization exercises in subjects with SDRS. Methods: Eighteen volunteer subjects (male=10, female=8) with SDRS were recruited for this experiment. All subjects performed MSE under 3 different conditions: (1) MSE, (2) MSE with an abdominal draw-in maneuver (ADIM), and (3) MSE with an abdominal expansion maneuver (AEM). The muscle thickness of the lower trapezius (LT) and the SA were measured using an ultrasonography in each condition. Electromyography (EMG) data were collected from the LT, LS, SA, and upper trapezius (UT) muscle activities. Data were statistically analysed using one-way repeated analysis of variance at a significance level of .05. Results: The muscle thickness of the LT and the SA were the significant different in the MSE, MSE with ADIM (MSE+ADIM) and MSE with AEM (MSE+AEM) conditions (p<.05) In both LT and SA, the order of thick muscle thickness was MSE+AEM, MSE+ADIM, and MSE alone. No significant differences were found in the EMG activities of the SA, UT, LS, and LT in all condition. Conclusion: In conclusion, MSE is more beneficial to people with SDRS when combined with trunk stabilization exercises by increased thickness of scapular stabilizer muscles.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.3
• /
• pp.1229-1237
• /
• 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 Korean Medicine Rehabilitation
• /
• v.20 no.1
• /
• pp.119-132
• /
• 2010

Objectives : The purpose of this study is to compare interrelations between stress and muscles of neck through stress response inventory(SRI), 7 zone diagnostic system and surface electromyography(sEMG). Methods : This study was carried out with the data from SRI, 7 zone diagnostic system and sEMG. First subjects were divided into two group according to the SRI points. subjects in group A had points of SRI in which lower than 30 points. Subjects in group B had points of SRI in which higher than 30 points. And subjects were divided into nonstress group(Group C) and stress grouop(Group D) according to the result of 7 zone diagnostic system. Then we investigated how to differentiate the muscle contraction, fatigue, recovery and asymmetry ratio on sEMG for each groups. Results : In this study, the muscle contraction of both upper trapezius muscle and left sternocleidomastoid muscle and left scalene muscle in stress group were higher than nonstress group significantly. And the muscle recovery of left sternocleidomastoid muscle and left scalene muscle in stress group were higher than nonstress group significantly. Conclusions : This results show that the stress was associated with muscle condition.

• The Korean Journal of Pain
• /
• v.14 no.1
• /
• pp.32-36
• /
• 2001

Background: There is no reliable objective test for the diagnosis of myofascial pain syndromes. The aim of this study was to evaluate the usefulness of a pressure algometer for the diagnosis of the trigger points and for the evaluation of the treatment in myofascial pain syndromes (MPS). Methods: Twenty female patients with clinical MPS of shoulder were included in this study. Pressure pain thresholds were measured by a pressure algometer at three different sites including the trapezius, supraspinatus and infraspinatus before, and then the 1st, 3rd and 7th days after TPI. Results: Mean pressure pain thresholds were lower in patients with MPS in than normal volunteers in all the examined skeletal muscles. Mean pressure pain thresholds in patients with MPS were increased significantly after TPI in all the examined skeletal muscles. Conclusions: Pressure algometer can be used as relatively objective diagnostic tool for locating trigger points and to quantify the effect of TPI in MPS. However, more investigation is necessary.

• Journal of the Ergonomics Society of Korea
• /
• v.22 no.2
• /
• pp.57-69
• /
• 2003

This study was performed to investigate the isometric endurance time as percentages of maximum voluntary contraction. Electromyogram(EMG) and Borg's CR-I0 value were measured by push-pull-up-down tasks for 10 healthy males. The normalized EMG value and the MPF(mean power frequency) were used to estimate the muscle recruitment pattern and the development of muscle fatigue. The subjects exerted and maintained 5 levels of %MVC(maximum voluntary contraction) in $90^{\circ}$ shoulder flexion/ 180oelbow extension at sitting posture. The up-task showed the lower endurance time and higher Borg's CR-I0 value than the other task types. Comparing Rohmert's curve with the endurance time of task types. Rohmert's curve overestimated the endurance time of up-task and underestimated the endurance time of push-pull-down tasks. The normalized EMG value showed that muscles recruitment patterns were different from task types. The 4 muscles(biceps brachii muscle, tricep brachii muscle. middle deltoid muscle. trapezius muscle) recruitment patterns of up-task were higher than those of other tasks. The MPF value decreased with the endurance time, and the shift of MPF at up-task was larger than that of the other task types.

• Physical Therapy Korea
• /
• v.14 no.2
• /
• pp.44-52
• /
• 2007

This study was carried out to compare the muscle activities of the shoulder stabilizers between persons with and without winging scapular during push-up plus exercise (adds the scapular protraction to the general push-up exercise). For this study, eleven males with winging scapular and eleven healthy males were recruited. Surface electromyographic (EMG) activity was recorded from the serratus anterior, upper trapezius, lower trapezius, infraspinatus, and pectoralis major while the subjects performed the push-up plus. Each push-up plus was subdivided into three phases according to the elbow position which was measured using the 3-D motion analysis system: elbow flexion (EF), elbow extension (EE), and shoulder protraction phases (SP). Two-way repeated measure ANOVA (phase ${\times}$ group) were used for statistical analysis. There was significant phase by group interaction only on the EMG composition ratio of the serratus anterior (p>.05). The EMG composition ratio of the serratus anterior was significantly higher in SP than in either EF or EE however, it was not different between winging scapular and normal groups. For both groups, the EMG composition ratio of upper trapezius, lower trapezius, and pectoralis major was significantly different across the phases of push-up plus, but the infraspinatus EMG composition ratio was not. For both groups, in EF and EE phases, the EMG composition ratio of both pectoralis major and serratus anterior were relatively higher than that of other muscles. However, in both groups, the EMG composition ratio of the serratus anterior became much more predominant than that of the pectoralis major. In addition, infraspinatus activated greater than pectoralis major. These results showed that the push-up plus exercise is effective to selectively strengthen the serratus anterior for both individuals with and without winging scapular, but not equally effective for other shoulder stabilizers.

• Journal of Oral Medicine and Pain
• /
• v.23 no.4
• /
• pp.379-385
• /
• 1998

A patient with TMJ osteoarthritis and anterior open bite was treated with an intermaxillary traction device. Pretreatment examination revelaed a pain in both TMJ during mouth opening, moderate tendernesso f left sternocleidomastoid and right trapezius muscles. Anterior open Bite was aobserved with interincisal distance of 2mm. Tomograms and MRI showed anterior disc displacement withouit reductoin of both temporomandibular joints, and the condyles were flattened and slightly eroded. A pair of full-coverage occlusal appliances was made on both maxillary and mandibular dentition, with pivoting fulcrum on the site of the second moalr. Traction force was gained by the intermaxillary orthodontic elastics which were hooked by orthodontic brackets on the labial surfaces of the upper and lower anterior and premolar teeth. After 8 weeks of traction treatment, the joint pain was subsided completely and the anterior open bite was closed to get an edge to edge relationship of anterior teeth.

• Journal of Oral Medicine and Pain
• /
• v.23 no.4
• /
• pp.369-377
• /
• 1998

A patient with TMJ osteoarthritis and anterior open bite was treated with an intermaxillary traction device. Pretreatment examination revelaed a pain in both TMJ during mouth opening, moderate tendernesso f left sternocleidomastoid and right trapezius muscles. Anterior open Bite was aobserved with interincisal distance of 2mm. Tomograms and MRI showed anterior disc displacement withouit reductoin of both temporomandibular joints, and the condyles were flattened and slightly eroded. A pair of full-coverage occlusal appliances was made on both maxillary and mandibular dentition, with pivoting fulcrum on the site of the second moalr. Traction force was gained by the intermaxillary orthodontic elastics which were hooked by orthodontic brackets on the labial surfaces of the upper and lower anterior and premolar teeth. After 8 weeks of traction treatment, the joint pain was subsided completely and the anterior open bite was closed to get an edge to edge relationship of anterior teeth.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.3
• /
• pp.1258-1265
• /
• 2013

The objective of this study is to investigate the association between touchpad &buttons locations in a laptop computer and EMG amplitude and median frequency in muscles related with wrist and shoulder. Based on previous studies it was shown how abductions in wrist and shoulder could cause musculoskeletal disorders in those body parts, on which research hypotheses were established. Touchpad &buttons positions consisted of bottom center(BC), bottom center with $45^{\circ}$ rotation counterclockwise(BCR), and bottom right(BR). 10 subjects performed the task that required only touchpad &buttons usage with their preferred hand and EMG amplitude and median frequency data were recorded during 5min and analyzed afterwards. Upper trapezius and flexor carpi ulnaris were selected as target muscles. The results showed that in flexor carpi ulnaris BC resulted in greater amplitude and less median frequency than BCR and BR, but there was no significant difference between BCR and BR. In upper trapezius BC and BCR induced higher amplitude and lower median frequency than BR, but the significant difference between BC and BCR was not observed. Those phenomena occurred since BC gave rise to both wrist and shoulder abduction, BCR caused only shoulder one, and BR did not lead to abductions in both wrist and shoulder.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
• /
• v.12 no.1
• /
• pp.57-67
• /
• 2006

Musculoskeletal neck dysfunction syndromes are common in outpatient musculoskeletal pain practice. The underlying musculoskeletal and neurologic causes of pain are variable. In the management of these patients, it is important to accurately identify and treat these pain generators to optimize patient outcome. It is the purpose of this review to discuss three main categories of functional anatomy, the role of superficial/deep muscular system and the scientific evidence for optimal physical therapy intervention for cervical dysfunction. Specifically there is evidence of lowered microcirculation in the upper trapezius muscle, morphological signs of disturbed mitochondrial function which appears to be limited to type I fibers and an increased cross-sectional area of type I muscle fibers despite a lower capillary to fiber area ratio. In acute neck pain syndrome, changes in muscle activity of painful muscles may result from segmental and supraspinal inhibitory effects. Muscle activation is closely related to the control of joint movements and postures and it is difficult to separate the influence of the two components. Both the altered muscle recruitment patterns and altered kinematics appear to be a poor adaptation for pain of the head - neck region, as they are likely to result in increased compressive loading in the cervical spine, affecting muscles, articular structures such as zygapophyseal joints, connective tissues and neural tissues which are all peripheral generators of referred pain. The rectus capitus posterior minor muscle shows that it is one of the most important muscles of the suboccipital region. In this article, i reviewed the anatomy, neurophysiology, function and dysfunction as well as the treatment of cervical dysfunction.