• Physical Therapy Rehabilitation Science
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• v.4 no.1
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• pp.22-27
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• 2015

Objective: Jump training helps increase the muscle power by improving the muscle strength and reaction time of the muscle in operation. The purpose of this study was to identify the effects of strengthening, stretching exercise and meditation on electromyographic (EMG) onset timing of rectus femoris and gastrocnemius muscle during vertical jump performance. Design: Cross-sectional study. Methods: Ten healthy adults (5 male and 5 female) who were familiar with the vertical jumping task and had no lower extremity injuries or any bone or joint disorders, were recruited for this study. Muscle onset timing was measured by surface EMG. After EMG onset timing were measured during performing three baseline vertical jump trials, strengthening and stretching exercises of the rectus femoris and gastrocnemius, and meditation were performed in random order. EMG onset timing was measured during vertical jump after intervention, respectively. EMG value was averaged for the three trials and analyzed using one-way repeated ANOVA. Results: During vertical jump, EMG onset timing of gastrocnemius was a significant difference after intervention (p<0.05), and then there was significantly faster in strengthening exercise than meditation (p<0.05). Conclusions: These results indicate the potential positive effect of performing strengthening exercise of the gastrocnemius before a jumping event. Future research is required to identify the effects of intervention over a long period.

• Physical Therapy Korea
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• v.13 no.1
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• pp.24-31
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• 2006

The purpose of this study was to identify the effect of the hip internal rotation on gluteal and erector spinae muscle electromyographic (EMG) activity during treadmill walking. Eleven healthy subjects were recruited. All subjects performed treadmill walking while maintaining the hip in neutral position (condition 1) and in internal rotation (condition 2). Surface EMG activity was recorded from four muscles (gluteus maximus (GM), gluteus medius (GMED), tensor fascia latae (TFL), and erector spinae (ES)) and the hip internal rotation angle was measured using a three dimensional motion analysis system. The gait cycle was determined with two foot switches, and stance phase was normalized as 100% stance phase (SP) for each condition using the MatLab 7.0 program. The normalized EMG activities according to the hip rotation (neutral or internal rotation) were compared using a paired t-test. During the entire SP of treadmill walking, the EMG activities of GM in condition 1 were significantly greater than in condition 2 (p<.05). The EMG activities of TFL and ES in condition 2 were significantly greater than in condition 1 (p<.05). The EMG activities of the GMED in condition 1 were significantly greater than in condition 1 (p>.05) except for 80~100% SP. Further studies need randomized control trials regarding the effect of hip internal rotation on the hip and lumbar spine muscle activity. Kinetic variables during gait or going up and down stairs are also needed.

• PNF and Movement
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• v.18 no.1
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• pp.107-116
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• 2020

Purpose: To investigate the effects of electromyography (EMG) biofeedback on the muscle activity of the trapezius, shoulder pain, function, and range of motion (ROM) in patients with subacromial impingement syndrome (SAIS). Methods: Sixteen patients (9 males and 7 females) with SAIS participated voluntarily. The main outcome measures were muscle activity of the trapezius, shoulder pain (VAS), ROM, and the shoulder pain and disability index (SPADI). Exercises with EMG biofeedback consisted of shoulder flexion in a standing position, shoulder external rotation in a side-lying position, and shoulder horizontal abduction in a prone position. Post measurements were taken immediately after EMG biofeedback training. Results: Middle and lower trapezius activity, as well as ROM, was significantly increased by exercise with EMG biofeedback (p<0.05). In addition, VAS and SPADI scores significantly decreased post-EMG biofeedback training (p<0.05). Conclusion: EMG biofeedback intervention is an effective exercise for SAIS patients to restore activity of the middle and lower trapezius and to improve pain, shoulder function, and ROM.

• Journal of Oral Medicine and Pain
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• v.21 no.1
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• pp.89-101
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• 1996

This study was performed to investigate influence of the changes of head posture on resting electromyographic (EMG) activity in anterior temporalis, masseter, sternocleidomastoid muscle and trapezius, and on status of occlusal contacts. For this study twenty-nine patients with temporomandibular disorders(TMD) and thirty dental students without any masticatory symptoms were selected as patients group and control group, respectively. EMG activity($\mu$V) at rest was observed in four kind of head postures such as natural or normal head posture(NHP), forward head posture(FHP), upward head posture(UHP), downward head posture(DHP), and in NHP and FHP, EMG activity with flat occlusal splint was also checked. BioEMG$^\textregistered$(Bioelectromyograph, Bioresearch Inc., USA) was used to record EMG activity in the above four muscles with eight locations on both sides. The author used T-Scan$^\textregistered$(Tekscan Co., USA) system to investigate the changes of oclusal contats on clenching in the four head postures about number, force, time(duration) and total left-right statistis(TLR, occlusal stability crossing left-right dental arch on clenching). For taking in upward or downward head posture, head was inclined $10^{\circ}$ upward or downward and CROM$^\textregistered$ (cervical-range-of motion, Performance attainment Inc., USA) was used to maintain same posture during the procedure. The results obtained were as follows : 1. For resting EMG activity, anterior temporalis did not show any difference by change of head posture, but masseter and sternocleidomastoid muscle showed higher value of EMG activity in FHP and UHP, and trapezius showed higher value of EMG activity in FHP and DHP. 2. EMG activity of trapezius was higher than that of any other muscles in NHP, FHP, and DHP, but in UHP, the activity was the lowest reversely. 3. Patients group showed higher EMG activity than control group did in all the muscles in NHP. And significant difference between the two groups were also observed in anterior temporalis in FHP, in sternocleidomastoid muscle in UHP, and in sterno-cleidomastoid muscle and trapezius in DHP with higher activity in patients group. 4. There was no change of EMG activity in NHp with splint, but EMG activity in anterior temporalis and masseter was decreased in FHP with splint. 5. In general, status of occlusal contacts was not changed with head posture in all subjects, and difference between patients group and control group was only noted for number and force of tooth contact in UHP and DHP with more value in control group. 6. Correlationship between EMG activity and number ad force of tooth contacts was shown negatively with regard to masseter in NHP, and trapezius in UHP and DHP.

• The Journal of Korean Academy of Prosthodontics
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• v.36 no.4
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• pp.598-614
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• 1998

This study was performed to investigate the influence of lateral guidance pattern and chewing pattern on masticatory muscle activity and occlusal contact pattern. Twenty-five patients with temporomandibular disorders and thirty students without temporomandibular disorders were selected for this study. Electromyographic examination and occlusal contact examination were performed simultaneously with Bio-Pak System (Bioresearch Inc.,U.S.A.) and T-Scan System(Tekscan Co., USA). The obtained results were as follows : 1. The EMG activity of masseter and anterior temporal muscle in patient group with canine guidance was higher than with non-canine guidance. but there was no significant difference (p>0.05). 2. The EMG activity of anterior temporal muscle in normal group with non-canine guidance was higher at preferred chewing side than at opposite side (p<0.05). 3. The EMG activity of masseter muscle was higher in normal group than in patient group (p<0.05). 4. The number of occlusal contact in patient group with canine guidance was higher than with non-canine guidance, but there was no significant difference (p>0.05). 5. The occlusal contact force at preferred chewing side was higher in patient group than in normal group(p<0.05).

• Journal of Korean Physical Therapy Science
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• v.19 no.2
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• pp.1-7
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• 2012

Purpose : The purpose of this study was to investigate the effect of different heel height on the electromyographic (EMG) activity in Rectus abdominis (RA) and Erector spinae (ES) during gait activity. Methods : A repeated measures design was used. 33 healthy females carried out a standardized gait activity under 3 conditions; with heel wedges of 1, 7, and 12cm in height. EMG activity was recorded from RA and ES during the activity. Data was analysed using the repeated one-way ANOVA. Results : First, as the shoe-heel height was getting higher, change of muscle activation indicated the statistically significant difference in rectus abdominis(p<0.05). Second, as the shoe-heel height was getting higher, change of muscle activation indicated the statistically significant difference in erector spinae(p<0.05). Conclusion : We found that as heel height increased, there was an increase in EMG activity in both RA and ES. This indicated that no RA : ES imbalance was elicited. This study provides information that will inform future research on how heel height affects muscle activity around the trunk.

• Physical Therapy Korea
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• v.20 no.3
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• pp.27-35
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• 2013

The aim of this study was to compare the electromyographic (EMG) activity levels of the scapular upward rotators [upper trapezius (UT), lower trapezius (LT), and serratus anterior (SA)] and other scapular muscles [posterior deltoid (PD), levator scapulae (LS), and infraspinatus (IS)] during isometric lower trapezius exercises. Twenty males with no medical history of shoulder pain or upper extremity disorders were recruited for this study. EMG activity was recorded from the UT, LT, SA, PD, LS, and IS while subjects performed three different exercises: Prone arm lift (PAL), Backward rocking diagonal arm lift (BRDAL), Modified Prone Cobra (MPC). One-way analysis of variance (ANOVA) was used to determine any significant differences among the three exercises. A lower relative activation of UT, LT, and SA was seen with the MPC than with the other exercises (p<.05). The relatively lower activation of the UT identified, the MPC exercise as the preferred choice for preferential strengthening the LT (p<.05). However, a higher activation in the PD, LS, and IS occurred with the MPC than with the other exercises (p>.05). The recruitment pattern of synergist varied depending on the exercise posture. These findings suggest that exercise posture is an important factor in the selection of strengthening exercise for weak muscle.

• Journal of International Academy of Physical Therapy Research
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• v.1 no.2
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• pp.185-191
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• 2010

Background: This study investigated effective posture for gluteus medius rehabilitation training and effects of isometric muscle activity by electrophysiology through EMG while performing dynamic isotonic behavior of weight placed differently on upper limbs. Method: 16 healthy male subjects 20 to 29 years of age volunteered for the study. Lateral stabilizer right gluteus medius activity was assessed using EMG while the right lower extremity maintains single limb support, and the left upper extremity elevation movement maintains 5 seconds without load, 1RM to 1 repetition, 5RM to 5 times, 10RM to 10 times, 5RM and 10RM maintain 5sec. Results: Comparison of the mean value of EMG data showed a statistically more significant difference in upper extremity elevation movement on opposite upper extremity added weight than one that was not added on a single limb weight bearing posture(p>.05). Weight supported side gluteus medius activity for 1RM, 5RM, 10RM weight difference and movement repetition did not differ(p>.05). Comparison in maximum value showed statistically significant differences in not adding weight on upper limb elevation exercise and 1RM, 5RM, 10RM repeated behavior. Elevation behavior and repetition appeared over 70% of MVIC. Conclusion: Unilateral weight bearing stance added weight in the opposite upper limb elevation movement was an indirect exercise to effectively stimulate gluteus medius activity. Applying various added weight will have effective exercise on the early stages of rehabilitation because activity gluteus medius did not differ through added weight.

• Physical Therapy Korea
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• v.17 no.2
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• pp.67-74
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• 2010

The purpose of this study was to examine the acute effects of nerve mobilization, static stretching, and hold-relax on the flexibility of hamstring muscles and their surface electromyographic (EMG) responses to passive stretches in poststroke hemiparesis. This study was a randomized cross-over trial. Fourteen subjects received three treatment sessions in random order with each consisting of ten repetitions. The treatment sessions included nerve mobilization, static stretching, and hold-relax. The treatment sessions were held at least 24 hours apart to minimize any carryover effect. The outcome was measured by the distance between the greater trochanter and lateral malleolus and hamstring EMG activity during passive knee extension stretching. Repeated-measures analysis of variance showed significant changes in hamstring flexibility and EMG activity in main effect of time pre, post and followup (p<.05). However, no significant differences occurred among the three stretching techniques. No technique was consistently found to be superior. The three stretching techniques in this study make it difficult to determine the most effective technique. Therefore, clinicians use nerve mobilization of effective stretching techniques with other stretching techniques.

• Journal of Korean Physical Therapy Science
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• v.23 no.1
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• pp.24-32
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• 2016

Purpose: Muscle imbalance around the knee region, especially quadriceps imbalance, is considered one of the main contributing factors to the development and progression of knee dysfunction based on the changes observed via electromyography (EMG). This study aimed to investigate the effect of vastus lateralis (VL) inhibition taping using non-elastic tape on the EMG activity of the vastus medialis oblique (VMO) and VL during isometric knee extension. Method: Thirty-three healthy young adults (11 males and 22 females) were recruited. With and without VL inhibition taping, the participants performed isometric knee extension in the sitting position for a total of 7 seconds. Result: VMO/VL EMG ratio significantly increased after VL inhibition taping (p<.05). Conclusion: These findings suggest that VL inhibition taping may contribute to VL inhibition and may help improve VMO/VL ratio in young adults. We expect VL inhibition taping to be useful in individuals with greater VL than VMO activity