• 한국전문물리치료학회지
• /
• 제24권4호
• /
• pp.1-10
• /
• 2017

Background: Flexion-relaxation phenomenon (FRP) was a term which refers to a sudden onset of myoelectric silence in the erector spinae muscles of the back during standing full forward flexion. Hamstring muscle length may be related to specific pelvic and trunk movements. Many studies have been done on the FRP of the erector spinae muscles. However, no studies have yet investigated the influence of hamstring muscle flexibility on the FRP of the hamstring muscle and lumbopelvic kinematics during forward bending. Objects: The purpose of this study was to examine the flexion-relaxation ratio (FRR) of the hamstring muscles and lumbopelvic kinematics and compare them during forward bending in subjects with different hamstring muscle flexibility. Methods: The subjects of two different groups were recruited using the active knee extension test. Group 1-consisted of 13 subjects who had a popliteal angle under $30^{\circ}$; Group 2-consisted of 13 subjects who had a popliteal angel above $50^{\circ}$. The kinematic parameters during the trunk bending task were recorded using a motion analysis system and the FRRs of the hamstring muscles were calculated. Differences between the groups were identified with an independent t-test. Results: The subjects with greater hamstring length had significantly less lumbar spine flexion movement and more pelvic flexion movement. The subjects with greater pelvic flexion movement had a higher rate of flexion relaxation during full trunk bending (p<.05). Conclusion: The results of this study suggest that differences in hamstring muscle flexibility might cause changes in people's hamstring muscle activity and lumbopelvic kinematics.

• 문화기술의 융합
• /
• 제9권2호
• /
• pp.519-524
• /
• 2023

이 연구는 경기상황과 유사한 점프 동작이 포함된 배드민턴 기술 동작 시 근육의 활성도의 차이를 조사함으로써 효율적인 기술훈련을 위한 기초자료를 구성하기 위한 목적이다. 남자 배드민턴 선수 7명을 대상으로 하여 스매시, 드롭, 클리어 기술을 무선배정으로 실시하였으며, 3가지 기술 동작 시행 중 근전도를 측정하였다. 측정된 근전도는 RMS로 산출하였으며 일원분산분석을 실시하였다. 스매싱 동작의 근활성도는 부위에 따른 유의한 차이를 보이지 않았다. 드롭 동작에서 상지 근육 중 PM의 활성도는 BC, ECR보다 낮았으며, FCR의 활성도는 EC보다 낮았다. ECR의 활성도는 PM, FCR보다 높았다. 몸통 근육 중 ES의 활성도는 RF, GM보다 낮았다. 하지 근육 중 RF의 활성도는 ES, BF보다 높았다. 클리어 동작에서 상지 근육 중 TC의 활성도는 FCR보다 높았다. 몸통 근육 중 ES의 활성도는 BF보다 낮았다. 하지 근육 중 RF의 활성도는 BF보다 높았으며, BF의 활성도는 RF, GM보다 낮았다. GM의 활성도는 BF보다 높았다. 배드민턴 기술에 따른 근활성도는 FCR에서 스매시와 드롭 동작이 클리어 동작보다 높았으며, RA에서 클리어가 스매시, 드롭 동작보다 높았다. 종합하면, 배드민턴 경기 중 근육활동은 기술별 특성에 따라 다르게 나타나고 노쪽손목굽힘근은 스매시와 드롭, 배곧은근은 클리어 동작에 영향을 미칠 수 있을 것으로 사료된다.

• PNF and Movement
• /
• 제15권3호
• /
• pp.303-310
• /
• 2017

Purpose: This study observed the activity of trunk and lower limb muscles during a modified bridging exercise with various weight loads. Methods: The participants in this study consisted of 15 male adults. The muscle activity of the elector spinae, rectus abdominis, gluteus maximus, gluteus medius, vastus medialis, vastus lateralis, tibialis anterior, and soleus muscles was measured with an EMG-8 system during a modified bridging exercise performed with various weight loads (indicated as percentage of body weight). Differences in muscle activity during the bridging exercise according to the weight load applied were analyzed using a one-way ANOVA, and post hoc analysis was performed using LSD. Statistical significance was accepted at a p-level of 0.05. Results: When the subjects performed the modified bridging exercise with various weight loads, the muscle activity of the gluteus maximus and vastus medialis peaked at a load of 0.5%. The activity of the gluteus medius showed a remarkable difference when the modified bridging exercise was performed at loads of 0% and 0.5%, 0% and 1%. In addition, the activity of the vastus medialis showed a remarkable difference between modified bridging exercises performed at a load of 0% and that performed at a load of 0.5%. Conclusion: The results suggest that performing modified bridging exercises with a load of 0.5% of body weight results in significant differences in the activity of the gluteus medius and vastus medialis muscles. Thus, it is suggested that performing the modified bridging exercise at 0.5% of body weight may selectively strengthen the gluteus medius and vastus medialis muscles.

• 한국전문물리치료학회지
• /
• 제19권2호
• /
• pp.29-38
• /
• 2012

This study aimed to identify the asymmetry observed in the electromyography (EMG) activity patterns of selected trunk and thigh muscles between the affected and unaffected sides during the sit-to-stand movement in ambulatory patients with post-stroke hemiparesis. This study included 20 patients with post-stroke hemiparesis. The differences between stroke fast walkers (${\geq}8m/s$, 11 subjects) and stroke slow walkers (<8 m/s, 9 subjects) were compared. The activation magnitude and onset time of the multifidus, lumbar erector spinae, hamstrings, and quadriceps during the sit-to-stand movement were recorded through surface EMG. Moreover, the EMG activation magnitude and onset time ratios of each bilateral corresponding muscle from the trunk and leg were measured by dividing the relevant values of the unaffected side by those of the affected side. In all the subjects, the activation magnitudes of the multifidus, hamstring, and quadriceps on the affected side significantly decreased compared to those on the unaffected side (p<.05). The onset time of muscle activity in the affected side was markedly delayed for the multifidus and quadriceps during the task (p<.05). The activation magnitude ratios of the quadriceps were markedly decreased in the stroke slow walkers as compared to those in the stroke fast walkers. These findings indicate that the asymmetry in the multifidus, hamstring, and quadriceps muscle activation patterns in patients with post-stroke hemiparesis may be due to the excessive muscle activation in the unaffected side to compensate for the weakened muscle activity in the affected side. Our findings may provide researchers and clinicians with information that can be useful in rehabilitation therapy.

• 한국전문물리치료학회지
• /
• 제21권2호
• /
• pp.28-36
• /
• 2014

The purpose of this study was to evaluate the changes in the electromyographic (EMG) activity of the trunk and the lower limb muscles during quiet standing on an unstable surface while wearing low-heeled shoes (3 cm), high-heeled shoes (7 cm) and without footwear (0 cm) in 20 young healthy women. The subjects stood on an unstable surface for 30 seconds. We examined the differences in the EMG data of the erector spinae, rectus abdominis, biceps femoris, rectus femoris, tibialis anterior, and the gastrocnemius medialis muscle. A one-way repeated analysis of variance was used to compare the effects of shoe heel height on the EMG activity with the level of significance set at ${\alpha}=.05$. The EMG activity of the erector spinae and the rectus femoris were significantly increased (p<.05) in the subjects who wore elevated heel height, while the tibialis anterior and the gastrocnemius medialis were significantly decreased (p<.05). However, the rectus abdominis and the biceps femoris exhibited no significant difference among the three conditions. The above results indicate that wearing high-heeled shoes may change the postural strategy. The findings of this study suggest that excessive heel height could contribute to an increased fall risk during quiet standing.

• 대한물리의학회지
• /
• 제8권4호
• /
• pp.655-666
• /
• 2013

PURPOSE: The main objective of this study is observing the effects of the functional postural trunk exercise (FPTE) on deep cranio-cervical flexor (CCF) muscle endurance applied on neck pain patients suffering from the acute whiplash-association disorder (WAD). METHODS: The study was tested with 47 patients with neck pain. All patients were equally treated with the ordinary therapy, only experimental group (n=23) was treated with FPTE: assumption of an upright lumbo-pelvic and spinal postural position, adding a neck lengthening manoeuvre in addition. Patients attended physical therapy for 3 times a week, for 4 weeks. Visual analogue scale (VAS) for pain, neck disability index (NDI), range of motion (ROM), were recorded both before and after the intervention. Also muscle activity in the CCF test was employed to analyze the changes between before and after. RESULT: After 4 weeks of training intervention, a remarkable increase in muscle endurance, rotation, extension ROM (p<.05) and decrease in pain and NDI (p<.05) in both groups. Further, the differences between groups were muscle endurance (F=60.350, p<.01), pain, and the left rotation ROM (p<.05). CONCLUSION: From the results, the experimental group had significant the increase in muscle endurance, and the significant decrease in pain. Whilst further research in this category is necessary, these observations suggest that applying exercise in early diagnosis can be of help to treat the neck pain patients suffering from the WAD.

• 한국운동역학회지
• /
• 제33권4호
• /
• pp.119-127
• /
• 2023

Objective: This study aimed to compare the activity of the trunk and leg muscles while performing fente (in fencing) wearing weighted and waterbag vests. Method: The electromyography test was used to measure and analyze the activation of the trunk and leg muscles. Eight active fencers from B University (age: 19.5 ± 0.66 years, height: 179.75 ± 5.93 cm, weight: 72 ± 6.32 kg) were selected for this study. Results: According to the EMG analysis results of the 4 muscles measured in this study, left-right differences were observed for rectus abdominis and external oblique abdominis, but left-right differences between the groups were not significant. The gluteus medius muscle was not significantly different from the adductor muscle, but there were significant differences between the groups. Conclusion: The electromyographic analysis of the four muscles measured in this study revealed no significant difference between the left and right recti abdominis and external obliques depending on the vests. However, significant differences were observed between the left and right gluteus medius and adductor longus. Our results can be interpreted as the effects of the inherent movements involved in the fente. Furthermore, our results indicate that the weight transfer while wearing a waterbag vest, which provides an unstable environment, increased the activity of leg muscles.

• 한국전문물리치료학회지
• /
• 제10권3호
• /
• pp.29-40
• /
• 2003

The purpose of this study was to compare the muscle activity during a push-up on a suspension sling and a fixed support at the same level. Tests were performed on 15 male subjects. Electromyography using a surface EMG recorded the activity of the triceps, pectoralis major, and internal and external oblique muscles during each push-up. EMG activity was recorded at 0, 45, and 90 degrees of elbow flexion in the push-up position on a suspension sling or a fixed support at the same height above the floor (30 cm). The testing order was selected randomly. The subjects were asked to maintain the push-up position with straight knees, hips, and trunk for 5 seconds at each elbow angle. The mean root mean square (RMS) of EMG activity was calculated. EMG activity was normalized using the maximum voluntary isometric contractιn elicited using a manual muscle testing technique. Two-factor repeated measures analysis of variance (ANOVA) was used to compare the average RMS value of EMG activity for each condition. The EMG activity for the pectoralis major, and internal and external oblique muscles during a push-up on a sling was significantly higher than on a fixed support at all angles of elbow flexion (p<.01). There were significant differences in the EMG activity of the pectoralis major and triceps brachii muscles at difference angles of elbow flexion (p<.05). The pectoralis major muscle had the highest EMG activity at 90 degrees of elbow flexion on both the sling and fixed support. The triceps brachii muscle had the highest EMG activity at 45 degrees of elbow flexion on both the sling and fixed support. The internal and external oblique muscles had the highest EMG activity at 0 degrees of elbow flexion, although the difference with angle of flexion was not significant. These results suggest that to improve proximal and trunk stability and muscle strength, push-ups are more useful when performed on a suspension sling than On a fixed support.

• 한국전문물리치료학회지
• /
• 제24권1호
• /
• pp.71-78
• /
• 2017

Background: Muscle weakness and impaired trunk muscle control are common in stroke patients. The bridging exercise (BE) is generally used for trunk stabilization and improving the overall function of stroke patients. The effectiveness of the BE with hip adductor contraction (BEHA) in facilitating trunk muscle activation has been well studied in healthy adults. However, the impact of BEHA in sub-acute stroke patients has not yet been investigated. Objects: The purpose of this study was to determine the effects of BEHA on the electromyography (EMG) activities and the asymmetry of the rectus abdominis (RA), external oblique (EO) and internal oblique (IO) abdominal muscles. Methods: Twenty participants with sub-acute stroke (11 males and 9 females) were recruited. Each participant was asked to perform bridging exercises for five seconds under three different conditions: BE in a neutral position (BEN), BEHA with a large ball (BEHAL) and BEHA with a small ball (BEHAS). The EMG amplitudes of the bilateral RA, EO and IO and the asymmetry of the EMG activity between the sound and affected sides were compared among the conditions. The significance level was set at ${\alpha}=.05$. Results: The EMG activities of RA, EO and IO were significantly greater during BEHAL and BEHAS than during BEN (p<.05); the asymmetry of the RA, EO and IO decreased significantly during BEHAL and BEHAS compared to BEN (p<.05). However, no measured variables showed any significant differences between BEHAL and BEHAS (p>.05). Conclusion: This study compared the EMG activities of the RA, EO and IO on both sides and the asymmetry of the RA, EO and IO during BEN, BEHAL and BEHAS. Our findings suggest that BEHA was more effective for individuals with hemiplegic stroke at facilitating and normalizing abdominal muscle control than BEN.

• 한국전문물리치료학회지
• /
• 제17권4호
• /
• pp.26-34
• /
• 2010

The purpose of this study was to compare the trunk and lower extremity muscle activity induced by six different conditions floor, intensity 0, 1, 3, 5 of whole body vibration (WBV), and Swiss ball during bridging exercise. Surface electromyography (EMG) was used to measure trunk and lower extremity muscles activity. Ten elderly women were recruited from Hong-sung Senior Citizen Welfare Center. The collected EMG data were normalized using reference contraction (during floor bridging) and expressed as a percentage of reference voluntary contraction (%RVC). To analyze the differences in EMG data, the repeated one-way analysis of variance was used. A Bonferroni's correction was used for multiple comparisons. The study showed that EMG activity of the rectus abdominis, external oblique, internal oblique, erector spinae and rectus abdominis muscles were not significantly different between six different conditions of during bridging exercise (p>.05). However, there were significantly increased EMG activity of the rectus femoris (p=.034) in the WBV intensity 0, 1, 3, and 5 conditions compared with the floor bridging condition. EMG activity of the medial gastrocnemius were significantly increased in the WBV intensity 0, 1, 3, 5 and Swiss ball conditions compared with the floor bridging condition. Future studies are required the dynamic instability condition such as one leg lifting in bridging.