Comparison of Upper Trapezius,Anterior Deltoid,and Serratus Anterior Muscle Activity during Push-up plus Exercise on Slings and a Stable Surface

[Purpose] The purpose of this study was to identify effects of push-up plus exercise on different support surfaces on upper extremity muscular activity. [Subjects] The subjects were 28 students (10 males, 18 females) at B University. [Methods] The subjects performed push-up plus exercises either on slings or on a fixed support. [Results] Push-up plus exercises on slings showed significant increases in the muscle activity of the trapezius (upper fiber), deltoid (anterior fiber), and serratus anterior muscles compared with stabilization exercises on a fixed support. [Conclusion] Based on these results, it is considered that performance of the push-up plus exercise on slings will increase scapular muscle activity.Key words: Push-up plus exercise, Sling, Muscle activity     

The Influence of an Unstable Surface on Trunk and Lower Extremity Muscle Activities during Variable Bridging Exercises

[Purpose] The aim of this study was to investigate the influence of an unstable surface on trunk and lower extremity muscle activities during various types of bridging exercises. [Subjects] Thirty healthy female adults voluntarily participated in this study. [Methods] All subjects were asked to perform 3 different bridging exercises (bridging exercise, single leg lift bridging exercise, single leg cross bridging exercise) with and without an unstable surface. The trunk and lower extremity muscle activities were measured by using surface electromyography during bridging exercise. [Results] During the bridging exercise (BE), single leg lift bridging exercise (LBE), and single leg cross bridging exercise (CBE), the muscle activities of the external oblique muscle (EO), erector spinae (ES), and biceps femoris (BF) were significantly higher on an unstable surface than on a stable surface. The muscle activities of the EO on both sides, contralateral BF, and ipsilateral ES were significantly higher during LBE than during BE and CBE. [Conclusion] Use of an unstable surface increases muscle activity of the trunk and lower extremities, and single leg lift bridging exercise increases the muscle activity of the EO on both sides, ipsilateral ES, and contralateral BF.Key words: Bridging exercise, Electromyography, Unstable surface     

Effect of the Push-up Plus (PUP) Exercise at Different Shoulder Rotation Angles on Shoulder Muscle Activities

[Purpose] Although the Push-Up Plus is a useful exercise method for shoulder stabilization, few studies have examined its effects at different angles of shoulder rotation. Therefore, the present study investigated the most effective exercise method for shoulder stabilization by analyzing muscle activities of the rotator cuff muscles at different angles of shoulder rotation. [Subjects] Fifteen healthy university students in their 20s were the subjects of this study. [Methods] Changes in muscle EMG related to shoulder stabilization were analyzed by performing the Push-Up Plus in shoulder positions of neutral, internal and external rotation. [Results] The highest muscle activity was found in external rotation, and in internal rotation the pectoralis major and levator scapula showed significantly lower activities than the other positions. [Conclusion] Selectively changing the rotation angle of the shoulder for different purposes of the shoulder exercise would be an effective exercise method.Key words: Shoulder, Stabilization, Rotation     

Electromyographic Activities of Trunk Muscles Due to Different Exercise Intensities during Pulley-based Shoulder Exercises on an Unstable Surface

[Purpose] This study examined the relationship between core stability and exercise intensity during a pulley-based shoulder exercise (PBSE) on an unstable support surface. [Subjects] Twenty healthy college students enrolled in this study. [Methods] Surface EMG was carried out in twenty healthy adult men. The electromyographic activities of the rectus abdominis (RA), erector spinae (ES), exercises with 14 kg or 26 kg of resistance and external oblique (EO) muscles during pulley-based shoulder on an unstable support surface (USS) were compared. [Results] The EMG signals of the RA, ES, and EO did not increase with increasing exercise resistance. [Conclusion] Increasing the exercise intensity to increase the core stability during PBSE on a USS may be ineffective.Key words: Electromyography, Core stability, Ankle strategy     

Effect of Virtual Reality Exercise Using the Nintendo Wii Fit on Muscle Activities of the Trunk and Lower Extremities of Normal Adults

[Purpose] The present study aimed to determine the effect of virtual reality exercise using the Nintendo Wii Fit on the muscle activities of the trunk and lower extremities of normal adults. [Subjects] The subjects of the study were 24 normal adults who were divided into a virtual reality exercise group (VREG, n=12) and a stable surface exercise group (SEG, n=12). [Methods] The exercises of the VREG using the Nintendo Wii Fit and the SEG using a stable surface were conducted three times a week for six weeks. Electromyography was used to measure the muscle activities of the tibialis anterior (TA), medial gastrocnemius (MG), erector spinae (ES), and rectus abdominal (RA) muscles. [Results] VREG showed significant within group differences in TA and MG muscle activities, while the SEG showed a significant difference in the muscle activity of the MG. [Conclusion] Virtual reality exercise using the Nintendo Wii Fit was an effective intervention for the muscle activities of the TA and MG of normal adults.Key words: Virtual reality exercise, Stable surface exercise, Muscle activity     

Effects of Shoulder Flexion Loaded by an Elastic Tubing Band on EMG Activity of the Gluteal Muscles during Squat Exercises

[Purpose] We investigated the effects of shoulder flexion loaded by an elastic tubing band during squat exercises, by assessing electromyographic activities of the gluteus maximus and gluteus medius. [Subjects] In total, 17 healthy males were recruited. [Methods] Participants performed squat exercises with and without shoulder flexion loaded by a tubing band. Gluteal muscle activities during the downward and upward phases of the squat exercises were recorded using a surface electromyography (EMG) system. The mean electromyographic activities of the gluteal muscles during squat exercises with and without loaded shoulder flexion were compared using the paired t-test. [Results] Electromyographic activities of the gluteus maximus and gluteus medius were greater in both the upward and downward phases of the squat with loaded shoulder flexion. [Conclusions] The combination of squat and loaded shoulder flexion can be an effective exercise for increasing gluteal muscle activity.Key words: Squat exercise, Gluteus maximus, Gluteus medius     

Effect of the Spacing of Backpack Shoulder Straps on Cervical Muscle Activity,Acromion and Scapular Position,and Upper Trapezius Pain

[Purpose] This study investigated the effect of the spacing of backpack shoulder straps on cervical muscle activity, acromion and scapular position, and upper trapezius (UT) pain. [Subjects] Fourteen males aged 20–32 years, were recruited. [Methods] We measured the MPS (midcervical paraspinal) activity, acromial angle, scapular distance, and UT pain after gait carrying a backpack with different shoulder strap spacings. [Results] The MPS, scapular inferior distance, and UT pressure pain threshold was significantly decreased and the acromion angle was significantly increased when carrying a backpack with wide shoulder straps compared to narrow shoulder straps. [Conclusion] A backpack with wide shoulder straps may cause scapular depression syndrome and chronic UT pain.Key words: Backpack, Scapular position, Shoulder straps     

The Effect of Trunk Stabilization Exercises with a Swiss Ball on Core Muscle Activation in the Elderly

[Purpose] The purpose of this study was to investigate the effects of trunk stabilization exercise on the muscle EMG activations related to core stability. [Subjects and Methods] Fifteen elderly people in a geriatric hospital performed trunk stabilization exercises with a Swiss ball for 20 minutes five times per week for 8 weeks. Trunk muscle activations were measured using electromyography before and after the intervention. [Results] After the intervention, the muscle activations of the rectus abdominis, erector spinae, lateral low-back (quadratus lumborum and external oblique), and gluteus medius muscles increased significantly. [Conclusion] The trunk stabilization exercise with a Swiss ball significantly increased the muscle activities of the elderly.Key words: Elderly, Electromyography, Core stability     

Effect of Wrist Joint Restriction on Forearm and Shoulder Movement during Upper Extremity Functional Activities

[Purpose] This study measured %isolation and investigated whether it shows a difference between the presence and absence of wrist joint restriction, as well as changes in muscle activity patterns. [Methods] Twenty subjects performed upper extremity functional movement in the Manual Function Test (MFT) with and without wrist restriction, and the muscle activities of the trapezius, middle deltoid, biceps brachii, triceps brachii, extensor carpi radialis, and flexor carpi radialis were recorded. When there were differences in muscle activation, %isolation was implemented and the changes in the muscle activity patterns were noted. [Results] In the grasping and pinching tasks, there was a significant increase in %isolation of the upper trapezius and a significant decrease in %isolation of the extensor carpi radialis. Carrying a cube task, %isolation of the upper trapezius and middle deltoid significantly increased, whereas %isolation of the triceps brachii and extensor carpi radialis significantly decreased. In the pegboard task, the %isolation values of the extensor carpi radialis and flexor carpi radialis significantly decreased. [Conclusion] The data of this study should be useful for therapists, who can employ the information as material for the education and treatment of patients with wrist joint restriction. Therapists may thus look for ways to improve the quality of mobility by predicting the complement mobility depending on the activity performed and then determine whether to facilitate or restrict mobility.Key words: Functional upper extremity activity, %isolation, Wrist joint restriction     

The Effect of Shoulder Flexion Angles on the Recruitment of Upper-extremity Muscles during Isometric Contraction

The purpose of this study was to investigate the differences in muscle activation patterns of the biceps brachii (BB) and flexor carpi radialis (FCR) muscles, while measuring the resultant force (RF) at different shoulder flexion angles. [Subjects] Thirteen healthy males (age 24.85±3.4 years, weight; 77.8±7.9 kg; height, 1.7±0.05 m) were enrolled in this study. [Methods] The resultant force was measured by a force transducer . The elbow angle remained constant and the flexion shoulder angle was changed (30°, 45°, 60°, 75° and 90°). [Results] The results of the surface EMG show the largest muscle activities occurred at a shoulder flexion of 75° for BB and 90° for FCR. The largest resultant force was measured at a shoulder flexion angle of 75°. We conclude, that when performing the biceps curl exercise using an arm curl machine, the shoulder should be flexed at 75° to maximize the focus of the exercise for the BB. [Conclusion] These results are useful from the perspective of design as they highlight the differences in the muscle activation of BB and FCR with postural change. Ultimately this knowledge can be used in the design of rehabilitation training for the shoulder as they show that posture can affect muscle activation.     

Effect of the Foot Placements on the Latissmus Dorsi and Low Back Muscle Activities during Pull-down Exercise

[Purpose] The purpose of this study was to examine the effects of foot placement on the latissmus dorsi and low back muscles activities during pull-down exercise. [Subjects] For this study, we recruited 10 male volunteers. [Methods] The subjects performed pull-down exercises with 4 foot placement conditions. The activities of the latissmus dorsi and L4 paraspinal muscles were measured. [Results] The activities of the latissmus dorsi muscles significantly increased in the order of conditions 1 and 2 < condition 4 < condition 3. The activities of the L4 paraspinal muscles were significantly different, with the activities of conditions 1 and 2 being greater than those of conditions 3 and 4. [Conclusion] We suggest that the selection of foot placement is an important factor for the effective strengthening of the latissmus dorsi.Key words: Foot placement, Latissmus dorsi, Pull-down exercise     

Effect of Thoracic Stretching,Thoracic Extension Exercise and Exercises for Cervical and Scapular Posture on Thoracic Kyphosis Angle and Upper Thoracic Pain

[Purpose] The purpose of this study was to investigate the effect of thoracic stretching, a thoracic extension exercise and exercises for cervical and scapular posture on thoracic kyphosis angle and upper thoracic pain. [Subject] A 36-year-old male, who complained of upper thoracic pain at the T1–4 level with forward head and round shoulders, was the subject. [Methods] He performed thoracic stretching (session 1), a thoracic extension exercise (session 2), and muscle exercises for cervical and scapular posture (session 3). [Results] The upper thoracic pressure pain threshold increased after session 1, session 2, and session 3. The thoracic kyphosis angle decreased after session 1, session 2, and session 3. [Conclusion] We suggest that intervention for thoracic pain or kyphotic thoracic correction should use not only an approach for extending the thoracic muscles, but also an approach treating muscles in the cervical and scapular region.Key words: Kyphosis, Posture correction, Thoracic pain     

Effects of Bilateral Passive Range of Motion Exercise on the Function of Upper Extremities and Activities of Daily Living in Patients with Acute Stroke

[Purpose] To evaluate the effects of early passive range of motion exercise on the function of upper extremities and activities of daily living in patients with acute stroke. [Methods] A total of 37 patients with acute stroke in intensive care units, were assigned to the experimental group (n=19) and control group (n=18). The experimental group performed passive range of motion exercise twice a day, for 4 weeks, immediately after a pretest; the patients in the control group performed the range of motion exercise in the same manner for 2 weeks beginning 2 weeks after the pretest. The functions of upper extremities (edema, range of motion), manual function, and activities of daily living of both groups were measured before and at four weeks after the intervention. [Results] The experimental group showed a significant decrease in the edema of upper extremities compared with the control group. It also showed a significant increase in the range of motion, function of upper extremities, and the activities of daily living compared to the control group. [Conclusion] Passive range of motion exercise in the early stage can improve the function of upper extremities and activities of daily living in patients with acute stroke.Key words: Stroke, Range of motion, Upper extremity     

The Effect of Self-directed Exercise Using a Task Board on Pain and Function in the Upper Extremities of Stroke Patients

[Purpose] We evaluated the effect of self-directed exercise using a task board on function and pain in the upper extremities of stroke patients [Subjects and Methods] We used the one group pre-post test design. Seven stroke patients who were selected based on the inclusion criteria participated in the program once a week for 10 weeks. The self-directed exercise comprised 5 stages that were divided according to the level of difficulty. The exercise was performed for 60 minutes using a special task board that we designed. The FMA (Fugl-Meyer Motor Assessment), VAS (Visual Analogue Scale), and speed of stacking were assessed to evaluate the amount of use of the affected arm at before and after intervention. [Results] The scores of the VAS and FMA, but not that of the speed of stacking cups, were improved. There was no significant correlation between the changes in VAS, FMA, and the speed of stacking cups. [Conclusion] The findings suggest that self-directed exercise with the task board could improve the levels of function and pain in the upper extremities. We suggest that self-directed exercise can be utilized as a clinical rehabilitation program and improve therapeutic effects.Key words: Self-directed exercise, VAS, FMA     

The Effect of Backpack Load on Muscle Activities of the Trunk and Lower Extremities and Plantar Foot Pressure in Flatfoot

[Purpose] The purpose of this study was to investigate the changes in muscle activation of the trunk and lower extremities and plantar foot pressure due to backpack loads of 0, 10, 15, and 20% of body weight during level walking in individuals with flatfoot. [Methods] Fourteen young flatfoot subjects and 12 normal foot subjects participated in this study. In each session, the subjects were assigned to carry a backpack load, and there were four level walking modes: (1) unloaded walking (0%), (2) 10% body weight (BW) load, (3) 15% BW load, and (4) 20% BW load. Trunk and lower extremity muscle activities were recorded by surface EMG, and contact area and plantar foot pressure were determined using a RS scan system. [Results] The erector spinae, vastus medialis, tibialis anterior and gastrocnemius muscle activities, but not the rectus femoris and rectus abdominis muscle activities of flatfoot subjects significantly and progressively increased as load increased in flatfoot subjects. Contact area and pressure of the lateral and medial heel zones were significantly increased too. [Conclusion] Based on this data, the weight of a backpack could influence muscle activation and plantar foot pressure in flatfoot.Key words: Flatfoot, Backpack, Plantar pressure     

Effect of Resting in a Chair,Resting with Range of Motion Exercises,and Back Strengthening Exercises on Pain and the Flexion-relaxation Ratio of Computer Workers with Low Back Pain

[Purpose] This study examined the effects of a relaxation chair and resting with simple range of motion exercises during computer work and low back muscle strengthening exercises after computer work on pain and the flexion-relaxation (FR) ratio of one computer worker with LBP. [Subjects] The subject of this study was a 37 year-old male who complained of severe LBP pain at the L4 level. [Methods] In the study, the subject worked on a computer for 5 h each day for 3 days and followed a different program each day. [Results] In Session 1, the FR ratios before and after work were 19% and 38% (+19%), respectively. The respective VAS scores before and after work were 5 and 8 (+3). In Session 2, the FR ratios before and after work were 18% and 21% (+3%), respectively. The respective VAS scores were 5 and 6 (+1). In session 3, the FR ratios before and work were 22% and 29% (+7%), respectively, and the VAS scores were 5 and 6 (+1). [Conclusion] This study suggests that it is more effective to perform regular, passive exercises to prevent LBP in computer users.Key words: Flexion-relaxation Ratio, LBP, Resting