Contemporary people want to develop their bodies to enhance quality of life. Although weight-training machines have been mainly developed with this trend based on intuition and experience, this study attempted to improve and verify those products through computer simulations using the musculoskeletal model of the human body. An arm-curl machine, a weight-training machine for arm exercise, was chosen for this research and the improved exercise effects were observed. The existing exercise that moves the scapula on the axis of the elbow with raised forearm is effective for biceps but not for triceps and adjacent muscles. Thus we suggested the idea for a new concept arm-curl machine that also raises the scapula after raising the forearm. To verify the effects of this new exercise, we manufactured arm-curl linkage. The experiments found that the exercise effects of the biceps were maintained, and the exercise effects of the triceps remarkably improved. These findings verified the effects of the proposed new concept arm-curl linkage.

본 연구의 목적은 플랭크 운동 시 세라밴드 적용 유·무에 따른 신체 근육의 근활성도를 비교·분석하는데 있었다. 본 연구의 대상자는 건강한 20대 남성 12명을 대상으로 실시하였고(연령, 21.75±0.57 세; 신장, 173.33±1.34cm; 체중, 65.92±1.64kg; 신체질량지수, 21.93±0.46kg/m2), 풀 플랭크, 엘보우 플랭크, 사이드 플랭크, 및 리버스 플랭크 운동은 4가지의 세라밴드(사용 안함(WT), 빨간색(RT), 파란색 (BT), 은색(ST))를 적용하여 수행하였으며, 표면전극 부착 부위는 척추기립근(ES), 삼각근(DA), 외복사근 (EO), 복직근(RA), 대퇴직근(RF), 광배근(LD), 대흉근(PM), 및 대퇴이두근(BF)으로 설정하였다. 본 연구의 결과는 다음과 같다. 풀 플랭크 동작 시 ES, DA의 근활성도는 WT적용 시 가장 높게 나타났고(p<.05), EO, RA, RF, PM의 근활성도는 ST적용 시 가장 높게 나타났다(p<.05). 엘보우 플랭크 동작 시 ES, DA의 근활성도는 WT적용 시 가장 높게 나타났고(p<.05), RF, PM의 근활성도는 ST적용 시 가장 높게 나타났다 (p<.05). 사이드 플랭크 동작 시 ES, EO, RA, RF, LD, PM, BF,의 근활성도는 ST적용 시 가장 높게 나타 났다(p<.05). 그리고 리버스 플랭크 동작 시 DA, EO, RA, RF, LD, PM, BF,의 근활성도는 ST적용 시 가장 높게 나타났다(p<.05). 따라서 본 연구의 결과는 향후 플랭크 운동 적용 시 효과적인 신체근육을 강화시 키기 위한 훈련프로그램의 자료가 될 것으로 기대된다.

Background: Sling exercises are frequently used for the rehabilitation process of patients with shoulder joint injuries, but research on the significant frequency intensity and appropriate treatment duration for sling exercises with local vibration stimulation is lacking. Objects: The aim of this study was to investigate the effects of sling exercise with vibration on shoulder range of motion (ROM), muscle strength, pain, and dysfunction in patients with a medical diagnosis of shoulder joint injury. Methods: Twenty-two patients were randomly assigned to the experiment and control groups. Six sling exercises with and without 50 ㎐ vibrations were applied in the experiment and control groups, respectively. Each exercise consisted of 3 sets of 5 repetitions performed for 6 weeks. The assessment tools used included shoulder joint range of motion, muscle strength, pain level, and shoulder pain and disability index for functional disability. We conducted re-evaluations before and 3 and 6 weeks after intervention. The changes in the measurement variables were analyzed and compared between the two groups. Results: The ROM of the external rotation of the shoulder joint had a significant interaction between the group and the measurement point (F=3.652, p<.05). In both groups, we found a significant increase in external rotation angle between the measurement points (p<.05). The flexor strength of the shoulder joint significant interaction between the group and the measurement point (F=4.247, p<.05). Both the experiment (p<.01) and control groups (p<.05) showed a significant increase in shoulder flexor strength at the measurement points. After 6 weeks of the interventions, both the groups showed significantly improved VAS (p<.01), SPADI (p<.01), and orthopedic tests (p<.01). However, there was no significant difference between the group and the measurement point in terms of the clinical outcomes observed. Conclusion: The sling exercise with local vibration of 50 ㎐ affected the external rotation of the shoulder range of motion and improved shoulder flexor strength in the patients with shoulder injuries. Therefore, we propose the use of the sling exercise intervention with vibration in the exercise rehabilitation of patients with shoulder joint injuries.

Background: Functional ankle instability (FAI) indicating a decrease in muscle strength, proprioception, neuromuscular control, balance and postural control function. Objective: To investigate the effect of jumping exercise on the supporting surface on the ankle muscle thickness, proprioceptive sensation, and balance in adults with FAI. Design: Randomized Controlled Trial. Methods: Twenty young people with FAI were randomly assigned to the unstable supporting surface jump group (N=10) and the stable supporting surface jump group (N=10). The intervention was conducted three times a week for eight weeks, and for 30 minutes per session. Trampoline was used as an unstable support surface and the stable support surface was carried out on a regular floor. The thickness of the tibialis anterior muscle and medial gastrocnemius muscle was measured by ultrasonography, and the proprioception of dorsiflexion and plantarflexion was measured using an electrogoniometer. The dynamic balance was also measured with a balance meter. Results: The the muscle thickness of the medial gastrocnemius muscle was significantly higher in the stable supporting surface jump group than in the unstable supporting surface jump group (p<.05). Furthermore, the plantar flexion proprioception and dynamic balance were significantly improved in the unstable supporting surface jump group than in the stable supporting surface jump group in the intergroup comparison (p<.05). Conclusions: The conclusion has been reached in this study that the jumping exercise on the unstable supporting surface could be a more effective in improving FAI than the regular surface.

Background: Improvement of the lumbo-pelvic stability can reduce the compensatory action of the erector spinae (ES) during prone hip extension (PHE). Furthermore, the application of abdominal drawing-in (ADI) maneuver increases the action of gluteus maximus (GM) and decreases the action of ES during PHE by improving the lumbo-pelvic stability. However, the post-ADI exercise effects on PHE, not the real-time application of ADI maneuver, has not been studied. Objects: This study is aimed at investigating the post-ADI exercise effects on the muscle activities of GM and ES during PHE. Methods: A total of 24 female adults participated in the study, and they were divided into two groups: Those with normal abdominal muscles (n1=12) and those with weak abdominal muscles (WA) (n2=12). Before the intervention, the subjects’ GM and ES muscle activities during PHE were measured. Subsequently, the two groups were asked to perform the ADI exercise for 10 minutes. After the ADI exercise, the GM and ES activities were equally measured during PHE. Results: The comparison result of the ES muscle activities before intervention shows a significant difference between the two groups (p<.05); the WA group showed higher muscle activities than the normal group. For the within-group comparison, the muscle activities of the ES in the WA group significantly decreased after the ADI exercise (p<.05). For the GM muscle activity, no significant difference was observed in all comparisons (p>.05). For the changes in muscle activities before and after the ADI exercise, a significant difference exists between the two groups only for the changes in ES activities (p<.05); WA group exhibits higher changes than the normal group. By contrast, no significant difference exists between the two groups for the changes in GM activities (p>.05). Conclusion: After the ADI exercise, the compensatory action of ES in the female adults with WC is implied to decrease during PHE.

Background: In previous studies, changes in postural alignment were found when the slope was changed during walking. Downhill walking straightens the trunk by shifting the line of gravity backward. Objects: This study investigated the effect of the downhill treadmill walking exercise (DTWE) on thoracic angle and thoracic erector spinae (TES) activation in subjects with thoracic kyphosis. Methods: A total of 20 subjects with thoracic kyphosis were recruited for this study. All the subjects performed the DTWE for 30 minutes. A surface EMG and 3D motion capture system were used to measure TES activation and thoracic angle before and after the DTWE. Paired t-tests were used to confirm the effect of the DTWE (p<.05). Results: Both the thoracic angle and TES activation had significantly increased after the DTWE compared to the baseline (p<.05). An increase in the thoracic angle indicates a decrease in kyphosis. Conclusion: The DTWE is effective for thoracic kyphosis patients as it decreases their kyphotic posture and increases the TES activation. Future longitudinal studies are required to investigate the long-term effects of the DTWE.

Background: Chronic low back pain (CLBP) causes morphological changes in muscles, reduces muscle strength, endurance and flexibility, negatively affects lumbar stability, and limits functional activity. Plank exercise strengthens core muscles, activates abdominal muscles, and improves intra-abdominal pressure to stabilize the trunk in patients with CLBP. Objects: We investigated the effect of plank exercise on abdominal muscle thickness and disability in patients with CLBP. Methods: We classified 33 subjects into 2 groups: An experimental (n1=17) and a control group (n2=16). Patients in the experimental group participated in plank exercise and those in the control group participated in stretching exercise. Patients in both groups attended 20-minute exercise sessions thrice a week for 4 weeks. Abdominal muscle thickness in each subject was evaluated ultrasonographically, and disabilities were assessed using the Oswestry disability index (ODI). Results: Four weeks later, abdominal muscle thickness showed a significant increase over baseline values in both groups (p<.05). Patients in the experimental group reported a more significant increase in the thickness of the external oblique muscle than that in the control group (p<.05). ODI scores in the experimental group were significantly lower after intervention than before intervention (p<.05). Conclusion: Plank exercise increases the thickness of the external oblique muscle and reduces disability secondary to mild CLBP. Therefore, plank exercise is needed to improve lumbar stability and functional activity in patients with mild CLBP.

Background: Stroke is one of the most common diseases responsible for physical disabilities. In addition to their physical and occupational therapy, the self-exercise programs were developed for patients with hemiplegia to increase the intensity of their therapeutic exercise. Objects: The purpose of this study was to assess the effect of a customized self-exercise program (CSP) to walking function on improving stroke survivors’ muscle strength and ambulation function. Method: To test the effect of the self-exercise program, the following tests were conducted: The functional ambulation category (FAC), Tinetti performance-oriented mobility assessment gait part (POMA-G), timed up and go (TUG), 10-meter walk, and 2-minute walk. The study included 161 consenting stroke patients (FAC score>1) from a randomized, screened sample of 217. The CSP group participated in a 30-minute CSP each day for 10 weeks in addition to completing a routine rehabilitation program. The control group received only a routine rehabilitation program. All the subjects were monitored by a therapist once a week and had to submit an exercise checklist at the end of each session. Result: The strength of the participants’ upper and lower extremity muscles showed no significant differences between the CSP group and the control group. The FAC score and POMA-G also showed no significant differences. However, there were significant differences in the TUG, 10-meter walk test, and 2-minute walk test (p<.05). Conclusion: The findings of this study suggest that a CSP may improve gait-related function in stroke survivors.

The purpose of this study was to investigate the effects of sling exercise on muscle activity and balance on football players with chronic ankle instability. Eight subjects performed Biodex and sling exercises for four weeks and compared the muscle activity and balance ability of the uninjured and injured feet. Stable and unstable foot % MVIC did not change significantly after treatment in all muscles. The total balance ability was not significantly different between the two groups, however, increased only in the unstable side. The anterior/posterior balance ability also represented no significant difference between the groups and was significantly improved only in the unstable side. The medial/lateral balance ability was not significantly different between the groups and was significantly improved only in the unstable side. This study suggests that sling exercise contributes to improving % MVIC, total balance ability, anterior/ posterior balance ability, and medial/lateral balance ability of the unstable side.

Background: Round shoulder posture, results from excessive flexed posture of the thorax, is defined as a position of scapular protraction, anterior tipping, and downward rotation. However, previous studies have focused on only passive position of the thorax during scapular posterior tilting (SPT) and have not reported on SPT combined with correction of flexed posture. Objects: The aim of this study was to compare effects of SPT and SPT with prone trunk extension (SPT + PTE) on activities of the lower trapezius, serratus anterior, and thoracic erector spinae and degree of posture in subjects with round shoulder and flexed posture. Methods: Fifteen subjects with round shoulder and flexed posture were recruited. The caliper was used to measure the degree of round shoulder and flexed posture. Electromyography was performed to collect data of muscle activities. Paired t-test was used to compare two exercise (α=.05). Results: When SPT + PTE was applied, the degree of round shoulder posture (p=.001) and flexed posture (p=.039) significantly decreased compared with that when SPT was applied. The lower trapezius activity significantly increased in the SPT + PTE condition compared with that in the SPT condition (p=.026). There were no significant differences in serratus anterior activity between SPT + PTE and SPT. The thoracic erector spinae activity significantly increased in the SPT + PTE condition compared with that in the SPT condition (p=.014). Conclusion: SPT + PTE might be one of the effective methods to enhance activities of lower trapezius and thoracic erector spinae, and to reduce round shoulder posture and flexed posture in subjects with round shoulder and flexed posture.

We investigated the effect of different exercise intensities on biomarkers of oxidant-antioxidant balance, inflammation, and muscle damage. Eighteen healthy and untrained male subjects were enrolled.Subjects were randomly and equally assigned to a moderate-intensityexercise(MIE, 65%VO2max) group(n=9) or a high-intensity exercise(HIE, 85%VO2max) group(n=9).Blood samples were collectedimmediately pre-exercise, post-exercise, and 60min post-exercisetoexamine oxidant-antioxidant balance(d-ROMs; BAP), inflammation(CRP; fibrinogen), muscle damage(CK; LDH), and lactate. Serum d-ROMs and BAP levels were significantly increased post-exercise compared with pre-exercise levels in HIE group(p<0.05). Lactate levels were significantly increased post-exercise compared pre-exercise levels in both the MIE and HIE groups(p<0.05). In addition, post-exercise serum d-ROMs and plasma lactate levels were significantly higher in the HIE group than in the MIE group(p<0.05). These results suggest that although relatively high-intensity exercises may increase oxidative stress levels in the body, they do not produce inflammatory response and/or muscle damage.

Background: Lumbopelvic stability is highly important for exercise therapy for patients with low back pain and shoulder dysfunction. It can be attained using a pelvic compression belt. Previous studies showed that external pelvic compression (EPC) enhances form closure by reducing sacroiliac joint laxity and selectively strengthens force closure and motor control by reducing the compensatory activity of the stabilizer. In addition, when the pelvic compression belt was placed directly on the anterior superior iliac spine, the laxity of the sacroiliac cephalic joint could be significantly reduced. Objects: This study aimed to compare the effects of EPC on lumbopelvic and shoulder muscle surface electromyography (EMG) activities during push-up plus (PUP) and deadlift (DL) exercise, trunk extensor strength during DL exercise. Methods: Thirty-eight subjects (21 men and 17 women) volunteered to participate in this study. The subjects were instructed to perform PUP and DL with and without the EPC. EMG data were collect from serratus anterior (SA), pectoralis major (PM), erector spinae (ES), and multifidus (MF). Trunk extensor strength were tested in DL exercise. The data were collected during 3 repetitions of all exercise and the mean of root mean square was used for analysis. Results: The EMG activities of the SA and PM were significantly increased in PUP with pelvic compression as compared with PUP without pelvic compression (p<.05). In DL exercise, a significant improvement in trunk extensor strength was observed during DL exercise with pelvic compression (p<.05). Conclusion: The results of this study indicate that lumbopelvic stabilization reinforced with external pelvic compression may be propitious to strengthen PUP in more-active SA and PM muscles. Applying EPC can improve the trunk extensor strength during DL exercise. Our study shows that EPC was beneficial to improve the PUP and DL exercise efficiency.

Background: The deep cervical flexor (DCF) muscles have a crucial role in the management of neck pain. For preventing neck pain by activation of the DCF, craniocervical flexion (CCF) is an effective exercise. However, sternocleidomastoid (SCM) muscle is considered to affect negatively the activation of the DCF. SCM muscle which is an accessory muscle for respiration is activated differently depending on types of breathing patterns. It’s not certain that breathing patterns affect the SCM and DCF muscles thickness during CCF exercise. Objects: The purpose of this study was to investigate the influence of breathing patterns on the SCM and DCF muscles thickness during CCF exercise. Methods: Forty-five subjects participated in this study, and they were classified according to their breathing pattern, as follows: Costodiaphragmatic breathing (CDB) and upper costal breathing (UCB) groups. Ultrasonographic imaging of the SCM and DCF muscles was performed during five incremental levels of CCF during tidal breathing and expiration. Results: There was a significant interaction between the breathing pattern and the phase of CCF for percentage of SCM muscle thickness changes (p˂.05). In phase 1 CCF, a percentage of SCM muscle thickness changes was increased in the UCB group than in the CDB group (p˂.05). There was an increase in DCF muscles thickness with each additional CCF phase (p˂.05). Conclusion: Recruitment of SCM muscle was increased in the UCB group while performing CCF with a low intensity. There were no significant differences on DCF recruitment between the breathing pattern groups. Higher CCF exercise intensities elicited a higher DCF recruitment.

The purpose of this study was to investigate the effect of heel off stairway walking exercise on the increase of muscle activity and balance activity of the ankle joint muscles in university students with functional ankle instability. The conservative treatment for the control group consisted of stairway walking (n=10) and the experimental group consisted of heel off stairway walking (n=11). The therapeutic intervention of the control and experimental groups was performed a total of 12 exercise sessions, 3 times per week for 4 weeks. To compare the two groups, the level of ankle disability was assessed by using the EMG, BT4 and Pedoscan in pre-treatment and post-treatment. Muscle activity increased in both the experimental groups and control groups in each group, however there was no significant difference between the groups. Balance ability did not show any significant difference. This study demonstrates that heel-off stairway walking is effective in significantly increasing muscle activity, however did not significantly improve balance ability.

The purpose of this study was to identify the effects of shoulder stabilization exercises and stretching on shoulder height and muscle activity in young adults with rounded shoulder posture. The subjects were young adults with rounded shoulder posture, and divided into two groups: shoulder stabilization exercises and stretching exercises. The shoulder stabilization exercise group performed Thera band exercises and stretching exercises. The stretching exercise group performed stretching exercises. The groups performed the exercises for 40min, three times a week for four weeks. Shoulder height was measure by Vanier calipers and muscle activity was measured by electromyography. Shoulder height was significantly decreased in both groups after intervention, however there was no difference between groups. There was a significant difference in muscle activity between the two groups after the intervention, however there was no difference between the groups. This study suggests that shoulder stabilization exercise and stretching affect shoulder height and muscle activity.

Background: The serratus anterior (SA) muscle is one of the important muscles in the upward rotation of the scapula when the arm is raised. Insufficient muscle activity of the SA can cause deformation of the shoulder rhythm resulting in shoulder pathology. Objects: This study intends to compare SA and upper trapezius (UT) activity during the conventional wall-slide and push-up plus exercises for SA muscle strengthening and the scapular upward rotation (SUR) exercise. Methods: A total of 30 subjects participated in this study, and we measured the muscle activity of the SA and UT muscles during the wall-slide, push-up plus and SUR exercises. The one-way repeated ANOVA was used to compare SA and UT muscle activities during the 3 exercises. Results: During the SUR exercise, SA muscle activity was 79.88% maximum voluntary isometric contraction (MVIC), which was significantly higher than its activity during the other 2 exercises. The UT muscle activity was 47.53 %MVIC during the SUR exercise, indicating a significantly higher UT muscle activity than during the other 2 exercises. Conclusion: These findings suggest that the SUR exercise can maximize SA muscle activity to strengthen the SA while keeping UT muscle activity at an appropriate level.

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° or 125° 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° and 125° shoulder flexion. Also, the SA/UT ratio measures at 90° and 125° 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° of shoulder joint was more effective than 90°. Conclusion: The findings suggest that scapular protraction with shoulder 125° 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.

This study aimed to identify the effects of modified low-dye taping and foot intrinsic muscle strengthening exercise on foot pressure in people with flat feet. The subjects were 12 participants with flat feet in their 20s. They were randomly divided into two groups: taping and strengthening exercise. They performed the interventions twice a week for six weeks. The taping group was applied the modified low-dye taping. The exercise group was performed foot intrinsic muscle strengthening exercise for 30 minutes. The data were measured by Foot Pressure Measurement. There was no significant difference in plantar pressure between taping group and exercise group. There was also no significant difference in all variables before and after intervention in all groups. The present study suggests that taping and exercise can change the foot pressure in patients with flat-footed.

Background: Scapular posterior tilt (SPT) is important in the prevention of abnormal scapular movement and pain during elevation of the arm. However, previous studies have overlooked increased upper trapezius (UT) muscle activity interrupting the normal force couple of scapular motion and compensation of levator scapulae (LS) muscle activated simultaneously with UT during SPT exercise. Objects: The purpose of this study was to compare the effects of modified SPT with depression exercise versus SPT exercise on serratus anterior (SA), lower trapezius (LT), UT, and LS muscle activities and the clavicular tilt angle, in subjects with rounded shoulder posture (RSP) and myofascial pain in the UT muscle region. Methods: Eighteen subjects with RSP were recruited and randomly allocated to 2 groups; 9 in the SPT group and 9 in the SPT with depression group. All subjects met the specific RSP criteria and had myofascial pain of UT region. Depending on the allocated group, subjects performed the assigned SPT exercise and EMG data were recorded during the each exercise. Clavicular tilt angle was defined as the angle between the line joining the medial and lateral end of the clavicle and a horizontal line. Results: The SA muscle activity was significantly greater in SPT with depression than with SPT exercise (p<.05). The UT, LS muscle activity and the clavicular tilt angle was significantly lower in SPT with depression than with SPT exercise (p<.05). Conclusion: These findings were insightful because the potential risk of pain from overactivation of the UT and LS was considered, in contrast with SPT exercise. SPT with depression exercise can be implemented as an effective method to facilitate scapular muscle activity for stability and to prevent myofascial pain in the neck and shoulder.

The purpose of this study was to compare the effects of respiratory exercise on cardiopulmonary function and muscle activity of rectus abdominis in smokers and non-smokers with elderly people. All the participants were older than 65 years, and twenty non-smokers, and twenty smokers participated. Non-smokers and smokers were randomly divined into 10 feedback breathing exercises (FBE) and a balloonblowing exercise (BBE) group. The FBE and the BBE were performed three times a week for four weeks. Forced vital capacity (FVC), forced expiratory volume at one second (FEV1), forced expiratory volume at one second/forced vital capacity (FEV1/FVC), peak expiratory flow (PEF), and vital capacity (VC) were measured as pulmonary function. EMG was used to measure the activity of the rectus abdominis. In the FBE and BBE groups, FEV1 was significantly lower in non-smokers compared to smokers at two and four weeks (p<.05), FEV1/FVC, PEF and VC were significantly lower in non-smokers compared to smokers to pre-test, two weeks, four weeks and six weeks (p<.05). Muscle activity of rectus abdominis was significantly difference in the BBE group at pre-test, two weeks, four weeks, and six weeks (p<.05). These results suggest that respiratory exercise was effective in improving pulmonary function and rectus muscle activity.