• PNF and Movement
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• v.15 no.3
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• pp.381-387
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• 2017

Purpose: Although some studies indicate that the Sorensen test may not be used to examine back muscles such as the erector spinae, alternatives to the back-extension test are rarely suggested. Therefore, the purpose of the present study was to investigate an effective way to stimulate the erector spinae muscles by adding a component of trunk rotation and lateral bending to general back extensions. Methods: A total of 18 healthy, physically active participants performed simple trunk extension, extension with trunk rotation, and extension with lateral bending. Surface electromyography responses of the latissimus dorsi, thoracic, and lumbar levels of the erector spinae; the gluteus maximus; and the biceps femoris muscles were investigated during these 3 conditions of modified back extension tests. Results: The simple trunk extension exercise caused significant increases in activity of the gluteus maximus and biceps femoris muscles as compared to the extension with rotation and lateral bending exercises. The extension with trunk rotation exercise showed significantly greater activation in the thoracic and lumbar levels of the erector spinae and in the latissimus dorsi as compared to the other exercises. The index measuring subjective difficulty was significantly lower in the simple trunk extension exercise as compared to the extension with trunk rotation and extension with lateral bending exercises. Conclusion: The present study suggests that extension with trunk rotation has the advantage of stimulating the para-spinal muscles, while simple trunk extension may not be adequate to selectively simulate the para-spinal muscles but may be appropriate for examining global trunk extensors.

• Physical Therapy Korea
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• v.19 no.2
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• pp.29-38
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• 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.

• Journal of The Korean Society of Integrative Medicine
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• v.4 no.4
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• pp.67-75
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• 2016

Purpose: The purpose of this study was to compare Hip-Knee-Ankle(HKA) angle and muscle activation ratio between vastus medialis(VM), rectus femoris(RF), and vastus lateralis (VL), and by this, to examine their relationship. It is aimed to explore how the activation ratio among the muscles involved in patellofemoral kinetics would vary in relation with the frontal alignment of the lower extremity. Subjects and Methods: 26 healthy subjects were recruited for the study. The HKA angles were measured with radiograph. The VM, RF, VL muscle activation level were measured by surface electromyography while each participant performed 4 different types of movement (isometric knee extension, squat, ambulation, step-up) and VM/RF, VM/VL, RF/VL ratios were calculated. Pearson correlation was used to estimate the relationship between the HKA angle and the muscle ratio. Results: There was significant moderate correlation between HKA angle and VM: RF on the left side during ambulation (p<0.05). Moderate correlations were also observed during step-up and squat with less significance (p<0.1). Conclusion: The frontal alignment of the knee measured by the HKA angle was conditionally associated with muscle activation ratio between VM and RF (VM:RF); On the left, during ambulation, step-up, and squat, the more valgus knee tended to correlate with the more VM muscle activation ratio, which is expected to induce more stabilizing effect to the patella and its tracking. It suggests that the frontal alignement measured by the HKA-angle can affect PF kinetics. It also indicates a possibility that increase in valgus alignment of the knee, by the HKA measurement, may not act unfavorably to generate PFP.

• Journal of the Korean Society of Physical Medicine
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• v.11 no.3
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• pp.119-124
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• 2016

PURPOSE: The aim of this study was to evaluate activation of accessory respiratory muscles using electromyography during chest expansion upper extremity flexion, abduction, and external rotation exercises with an elastic band in children with cerebral palsy. METHODS: The subjects were 10 children with cerebral palsy. The inclusion criterion for participation was a Gross Motor Function Classification System level of I to III. The subjects were instructed to perform upper extremity flexion, abduction, and external rotation exercises with inspiration, and extension, adduction, and internal rotation exercises with expiration while seated on a chair without a backrest. PM (Pectoralis major), SCM (sternocleidomastoid), RA (rectus abdominis), and EO (external oblique) muscle activities were measured using electromyography. RESULTS: All tested muscles showed a statistically significant increase in activity after elastic band exercise. There were significant differences in PM, SCM, RA, and EO results after chest expansion exercise using elastic band. SCM showed the largest increase in activity after use of elastic bands, at $52.37{\pm}45.88$%, followed by the RA ($50.56{\pm}79.31$), EO ($35.42{\pm}35.45$), and PM ($31.72{\pm}25.64$). The increase in the SCM was greatest, followed by increases in the RA, EO, and PM CONCLUSION: These finding suggest that activity of accessory respiratory muscles increases with use of elastic bands during chest expansion exercise in cerebral palsy.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.7
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• pp.805-810
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• 2012

Determining of the exercise intensity is very important in terms of induction of low fatigue during exercise. Little information is available on the contraction level of the trunk muscles during whole body tilts with and without axial rotation. This study was to investigate the difference muscle activation level according to axial rotation. Twenty subjects were participated. The muscle activities of the five trunk muscles were bilaterally measured at eight axial rotation angles with 12 tilt angles along $15^{\circ}$ intervals. The results showed that tilt with $45^{\circ}$ axial rotation was more balanced in the same tilt angle and was maintained approximately level of 40% MVC at over $60^{\circ}$ tilt angle with respect to co-contraction of abdominal and back muscle. Lumbar stabilization exercise using whole body tilts would be more effective with axial rotation than without axial rotation in terms of muscle co-contraction.

• Physical Therapy Rehabilitation Science
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• v.8 no.2
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• pp.86-92
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• 2019

Objective: The purpose of this study was to compare the effects of performing squats and kneeling squats on trunk and lower extremity muscle activity in persons with stroke. Design: Cross-sectional study. Methods: Ten persons with stroke (3 male and 7 female) were recruited. The subjects were instructed to randomly perform the 4 different squat conditions: squat with 30 degrees of knee flexion, squat with 60 degrees of knee flexion, squat with 90 degree of knee flexion, and the kneeling squat. During the squat performance, surface electromyograms (sEMG) was used to assess muscle activity of the erector spinae (ES), gluteus maximus (Gmax), gluteus medius (Gmed), and biceps femoris (BF) muscles. Results: Muscle activation of the ES and BF were significantly increased with the kneeling squats compared to the general squats with 30 degrees and 60 degrees of knee flexion (p<0.05), and muscle activation of the Gmax and Gmed were significantly increased with the kneeling squats compared to all other squat conditions (p<0.05). Conclusions: The results suggest that the kneeling squat is an effective exercise to strengthen the proximal muscles of the lower extremities. Rather than applying a difficult general squat to the stroke population, the kneeling squat may be applied as a safer method for training the proximal muscles.

• Journal of International Academy of Physical Therapy Research
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• v.12 no.2
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• pp.2338-2344
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• 2021

Background: The therapeutic exercise method using kinesiology taping (KT) has been reported to be effective in activating the suprahyoid muscle in healthy adults. However, its applicability and effectiveness are not known to the physically vulnerable elderly. Objectives: To investigate the effects of kinesiology taping on the activity of suprahyoid muscles in community-dwelling elderly people. Design: Repeated measure design. Methods: We enrolled 23 healthy elderly adults (age range 60-75 years) with no history of neurologic disease. Participants performed five consecutive spontaneous swallowing actions at 5-second intervals under three conditions (KT with 80% stretch, placebo-KT, and non-KT. Activation of the suprahyoid muscles during swallowing in the three conditions was measured using surface electromyography (sEMG). In addition, a 0-10 numerical rating self-report scale was used to evaluate the required effort and the resistance felt during swallowing. Results: KT with 80% stretch were significantly higher in sEMG mean value, peak value, required effort, and resistance felt during swallowing compared to other two conditions (P<.05, all). KT with 80% stretch required the most effort during swallowing and, consequently, has a positive effect on increasing suprahyoid muscle activation. Conclusion: Our results could be taken into consideration in therapeutic exercise method for suprahyoid muscle in dysphagia rehabilitation.

• PNF and Movement
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• v.18 no.3
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• pp.315-321
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• 2020

Purpose: Recent studies have indicated that applying different inclination angles and suspension devices could be a useful way of performing exercises that include the co-activation of the trunk muscles. Present study was to examine the influences of changes in the inclination angle during trunk muscle activity while engaging in a bridge exercise with a suspension device. Methods: 18 healthy, physically active male volunteers completed three trunk inclination angles (15°, 30°, and 45°) for bridge exercise variations. The surface electromyography responses of the rectus abdominis, internal oblique (IO), erector spinae (ES), and rectus femoris (RF), as well as the subjective difficulty (Borg RPE score), were investigated during these bridge exercises. Results: The bridge with a 45° inclination angle suspension significantly increased the muscular activities of the RA and RF and increased the Borg RPE scores (p<0.05). The bridge with a 15° suspension significantly elevated the ES activities when compared to the other conditions. Conclusion: The present study demonstrated that a higher inclination angle could not activate the overall trunk muscles during the bridge exercise. The RA and RF produced greater activation during the bridge exercise with the higher inclination angle. On the other hand, the activities of the erector spine were greater during the bridge exercise with the lower inclination angle. The present study suggests that applying a low trunk inclination angle for the supine bridge exercise is suitable for activating the erector spine muscles.

• Journal of the Korean Society of Physical Medicine
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• v.18 no.3
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• pp.65-72
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• 2023

PURPOSE: This study assessed the influence of bilateral coordination exercises on unstable support surfaces on leg muscle activation and balance in stroke patients. METHODS: Two groups were recruited for comparison: an experimental group of 10 individuals who performed bilateral coordination exercises on unstable surfaces and a control group of 10 individuals who performed the same exercises on stable surfaces. All participants were assigned randomly. Pre-tests were conducted to measure the leg muscle activation and balance levels of the participants prior to the experiment. The intervention was comprised of three 30-minute weekly sessions for four weeks, followed by a post-test after the four-week period. RESULTS: Significant differences were identified within the experimental group in relation to all muscles (p < .01) and balance (p < .05). Within the control group, significant differences were identified in relation to the rectus femoris muscle, biceps femoris muscle, and balance (p < .05). Significant differences between the two groups were only observed in relation to the tibialis anterior and soleus muscles (p < .05). CONCLUSION: Only the tibialis anterior and soleus muscles showed significant differences between the two groups. This effectiveness may be attributed to using an ankle strategy to maintain body balance during exercise on unstable surfaces.

• Journal of Biomedical Engineering Research
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• v.45 no.2
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• pp.66-74
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• 2024

This study analyzed the occurrence of abnormal muscle coactivations based on the assistance of upper limb weight during reaching task in stroke patients. Nine chronic stroke survivors with hemiplegia performed reaching tasks using a programmable haptic robot. Electromyography (EMG) coactivation levels in the upper limb muscles were analyzed using a linear model describing the activation levels of two muscles when the patient's upper limb weight was assisted at 0%, 25%, and 50%. As the upper limb weight assistance of the haptic robot decreased, the magnitude of the EMG signal in both the deltoid and biceps muscles increased simultaneously on both the paretic and non-paretic sides. However, no difference was found between the paretic and non-paretic sides when comparing the slope of the linear model describing the activation relationship between the deltoid and biceps. The aforementioned results suggest that in some stroke survivors, the deltoids, triceps, and biceps on the paretic side may not be abnormally coupled when supporting the upper limbs against gravity. Furthermore, these results suggest that the combination of haptic robots and EMG analysis might be utilized for evaluating abnormal coactivations in stroke patients.