• Journal of Oral Medicine and Pain
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• v.15 no.1
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• pp.37-44
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• 1991

The author has synchronously recorded average electromyographic activities of temporalis anteriors and masseter muscles and the maximum bite force on the mandibular first molar on the prferred chewing side. These activities were recorded in order to study the EMG activity pattern of the working side and the balancing side to maximum bete force and functioning state of muscle in 30 patients with TMD and in 30 healthy subjects as controls. The results were as follows : 1. The maximum bite force on the mandibular first molar on the preferred chewing side was 20.63kg in TMD patients and 53.30kg in the healthy subjects(p<0.01). The maximum bite force in TMD patients was 38.7% of the healthy subjects. 2. The average electromyographic activities of temporalis anterioris and masseter muscles on the working side and the balancing side during maximum bite force were lower in TMD patients than in the healthy subjects(p<0.01). The average electromyographic activities of each muscle in TMD patients were 61.0%-62.8% of the healthy subjects. 3. The proportionalities of average electromyographic activities of temporalis anteriors and masseter muscles on the working side and the balancing side to maximum bite force were greater in TMD patients than in the healthy subjects(p<0.01). 4. Between the working side and the balancing side, the proportionality of average electromyographic activity of temporalis anterior to maximum bite force on the working healthy subjects (p<0.01). The proportionality of average electromyographic activity of working side and the balancing side in both groups (p<0.05).

• Physical Therapy Korea
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• v.17 no.2
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• pp.1-9
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• 2010

To develop effective training methods for strengthening a weakened quadriceps femoris muscle in hemiplegic patients, we examined the effects of maximal isometric contraction of the nonparalyzed knee joint on the electromyographic activities of the paralytic muscle. An electromyogram (EMG) was used to record the electromyographic activities of the paralytic quadriceps femoris muscle in 27 hemiplegic patients. The maximal isometric contraction was measured for each subject to normalize the electromyographic activities. The maximal isometric extension and flexion exercises were randomly conducted when the knee joint angles of the nonparalyzed knees were $0^{\circ}$, $45^{\circ}$, and $90^{\circ}$. The patients were encouraged to maintain maximal isometric contractions in both knee joints during each measurement, and three measurements were taken. A one-minute rest interval was given between each measurement to minimize the effects of muscle fatigue. An average from the three values was taken as being the root mean square of the EMG and was recorded as being the maximal isometric contraction. The electromyographic activity obtained for each measurement was expressed as a percentage of the reference voluntary contraction, which was determined using the values obtained during the maximal isometric contraction. The results of this study are summarized as follows: First, when the knee joint angle of the nonparalyzed knee was $0^{\circ}$, the electromyographic activities of the paralytic medial aspect of rectus femoris were related to measurement by a maximal isometric flexion exercise than by an extension exercise (p<.05). Second, when the knee joint angle of the nonparalyzed knee was $90^{\circ}$, the electromyographic activities of the paralytic lateral aspect of rectus femoris were related to measurement by a maximal isometric flexion exercise than by an extension exercise (p<.05). The results show that myoelectrical activities of paralytic quardriceps were not related to measurement angles and exercise directions of the nonparalized knee joint. Studies on various indirect intervention to improve muscular strength of patients with nervous system disorders of the weakened muscle should be constantly conducted.

• Journal of Oral Medicine and Pain
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• v.18 no.1
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• pp.55-62
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• 1993

The author has synchronously recorded the average electromyographic activities of the sternocleidomastoid muscles, the anterior temporal muacles and the masseter muscles. The marious levels of occlusal force were checked during clenching the resin plates which are made to fit each of the maxillary and the mandibular teeth. These activities were recorded in order to study the EMG activity pattern of the sternocleidomastoid muscle during the masticatory function of the jaw in 11 healthy subjects. The obtined results were as follows : 1. The electromyographic activities of the sternocleidomastoid muscles, the anterior temporal muscles and the masseter muscles were increased as the occlusal force increased, and the sternocleidomastoid muscles have a lineal correlationship with the occlusal force. 2. The sternocleidomastoid muscles and the masseter muscles showed higher EMG activity during clenching at the ventroflexed head position rather than at the extended head position. (p<0.05) However the EMG activities of the anterior temporal muscles showed no difference between the ventroflexed position and the extended position of the head. 3. The electromyographic activities of the sternocleidomastoid muscles, the anterior temporal muscles and the masseter muscles during clenching are similar at the habitual position and at the retruded condylar position. 4. The electromyographic activities of the sternocleidomastoid muscles, the anterior temporal muscles and the masseter muscles on the working side during mastication of gum and almonds are significantly higher than on the balancing side except the masseter muscles during mastication of almonds. (p<0.05, P<0.01) 5. The asymmetry of gum are lower than that during mastication of almonds. (p<0.05) The asymmetry indices of the sternocleidomastoid muscles are higher than those of the anterior temporal muscles and masseter muscles.

• The Journal of Korean Physical Therapy
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• v.13 no.3
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• pp.829-837
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• 2001

Using Video Display Terminals(VDT) in the working environment often causes health complaints in the neck and shoulder region. This study was conducted on ten subjects, in order to investigate the change of electromyographic activities in the neck region(sternocleidomastoid muscle, upper trapezius muscle and erector muscle of cervical spine)with regards to the screen height and document holder position. A total of six different conditions of screen height and document holder position were measured during subjects performed a text-entry task for a duration of 10min. The raw EMG signal was transmuted into the root mean square(RMS). Two-way ANOVA for repeated measures was used to analyse the effects of the two factors. As a result, changing the screen height and document holder position has no effect on electromyographic activities in the neck region.

• The Journal of Korean Academy of Prosthodontics
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• v.22 no.1
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• pp.85-94
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• 1984

The purpose of this study was to investigate treatment effectiveness of TENS and bite plane for bruxism and TMJ dysfunction patients. The electromyograms were made on males aged 23 to 25 with sound stomatognathic system, 5 males bruxism aged 24 to 27, and 1 male and 4 females TMJ dysfunction patients (right TMJ pain) aged 14 to 33. The electromyographic study was limited to the middle of masseter muscle and anterior temporal muscle. The electromyographic study was carried out with 8-channel EM2 (Myotronics Research Inc.) and was taken 5 mandibular positions of clinical rest position, clench intercuspal position, clench protruded, cluch right, clench left. The 2 pairs of surface electrodes were used exactly, with the ear lobe as reference point. The recording were subjected to determine the mean voltage. The results were as follows; 1. In the clinical rest position, the muscle activities of bruxism and TMJ dysfunction patients were higher than those of normal at the before treatment, but that were lower or similar to those of normal at the TENS after and after bite plane wearing. 2. In the clench I.C.P., the muscle activities of TMJ dysfunction patients were decreased as the order of the before treatment, after TENS, after occlusal bite plane wearing, but those of bruxism were irregular. 3. In the clench right and the clench left, the muscle activities of the middle of masseter muscle of the non-working side of bruxism were higher than those of the working side at the before treatment and after TENS, but the muscle activities of after occlusal bite plane wearing were similar to those of the normal. 4. In the clench right and the clench left, the muscle activities of the middle of masseter muscle and anterior temporal muscle of the working side of TMJ dysfunction patients were higher than those of non-working side as like the normal at the before treatment, after TENS, and after occlusal bite plane wearing.

• Physical Therapy Korea
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• v.26 no.2
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• pp.16-23
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• 2019

Background: High-heeled shoes can change spinal alignment and feet movement, which leads to muscle fatigue and discomfort in lumbopelvic region, legs, and feet while walking. Objects: This study aimed to identify the effects of different shoe heel heights on the walking velocity and electromyographic (EMG) activities of the lower leg muscles during short- and long-distance walking in young females. Methods: Fifteen young females were recruited in this study. The experiments were performed with the following two different shoe heel heights: 0 cm and 7 cm. All participants underwent an electromyographic procedure to measure the activities and fatigue levels of the tibialis anterior (TA), medial gastrocnemius (MG), rectus femoris (RF), and hamstring muscles with each heel height during both short- and long-distance walking. The walking velocities were measured using the short-distance (10-m walk) and long-distance (6-min walk) walking tests. Results: Significant interaction effects were found between heel height and walking distance conditions for the EMG activities and fatigue levels of TA and MG muscles, and walking velocity (p<.05). The walking velocity and activities of the TA, MG, and RF muscles appeared to be significantly different between the 0 cm and 7 cm heel heights during both short- and long-distance walking (p<.05). Significant difference in the fatigue level of the MG muscle were found between the 0 cm and 7 cm heel heights during long-distance walking. In addition, walking velocity and the fatigue level of the MG muscle at the 7 cm heel height revealed significant differences in the comparison of short- and long-distance walking (p<.05). Conclusion: These findings indicate that higher shoe heel height leads to a decrease in the walking velocity and an increase in the activity and fatigue level of the lower leg muscles, particularly during long-distance walking.

• Journal of Oral Medicine and Pain
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• v.16 no.1
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• pp.25-32
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• 1991

The author studied the changes of electromyographic activities of the masseter and anterior temporal muscles during maximal clenching before and after stabilization splint wearing. It also studied the changes of the symmetry of the muscle activity during maximal clenching. For this study, 15-healthy-female-students were selected. The obtained results were as follows : The EMG activities of right and left anterior temporal muscles and right masseter muscle during maximal clenching immediately after wearing of the stabilization splint were not changed compared with before wearing of the stabilization splint. The EMG activities of right and left masseter and anterior temporal muscles during maximal clenching were significantly increased after 1 week and 4 week-use of the stabilization splint(p<0.01). The asymmetric indices of the EMG activities of right and left masseter and anterior temporal muscles during maximal clenching immediately after wearing of the stabilization splint were not changed compared with before wearing of the stabilization splint. The asymmetric indices of the EMG activities of right and left anterior temporal muscles during maximal clenching were significantly decreased after 1 week and 4 week use of the stabilization splint(p<0.01). and that of masseter muscles showed a decreased tendency but there were no significant differences(p>0.05).

• Korean Journal of Applied Biomechanics
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• v.20 no.3
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• pp.303-310
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• 2010

The purpose of this study was (a)to compare electromyographic (EMG) activities and physiological variables on the development of fatigue induced by ergometer test, (b)to determine investigate the differences in the stage of fatigue between the electromyographic characteristics and physiological variables. Nine male university students who have no musculoskeletal disorder were recruited as the subjects. The electromyographic characteristics(peak IEMG, average IEMG, median frequency, mean edge frequency) and physiological variables(HR, RPE, blood lactate) were determined for each stage(15, 30, 45, 60 minutes, all out). For each dependent variable, one-way analysis of variance(ANOVA) with repeated measures and correlation analysis were performed to test if significant difference existed(p<.05). The results showed that peak IEMG, average IEMG from low extremity and physiological variables were significantly increased during the all-out stage. EMG parameters in VL, VM show significantly correlation with physiological variables during whole stages. This indicated that IEMG values may be proper parameters to determine muscle fatigue rather than physiological variables.

• Physical Therapy Korea
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• v.4 no.1
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• pp.1-10
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• 1997

The purposes of this study were to compare the electromyographic activities from the rectus femoris, vastus medialis oblique portion, vastus medialis longitudinal portion, and vastus lateralis during straight leg raising (SLR) and quadriceps setting (QS) exercise and to determine which exercise is more effective to selectively strengthen the vastus medialis. Thirty two healthy subjects <19 men, 13 women) participated in the study. All participants performed SLR and QS exercises while electromyographic activity was recorded from EMG surface electrodes. Statistical analysis demonstrated significantly greater values for the vastus medialis oblique portion, vastus medialis longitudinal portion, and vastus lateralis activities during QS exercise than for those during SLR exercise. However, the rectus femoris muscle activity between SLR and QS exercises was not significantly different. The ratios of vastus lateralis to vastus medialis during SLR and QS exercise were not significantly different. These results show that QS exercise is more effective for strengthening the quadriceps muscle on the whole than the SLR exercise. As for selective methods of strengthening vastus medialis specifically, both SLR and QS exercises are useful.

• Physical Therapy Korea
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• v.14 no.3
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• pp.9-15
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• 2007

The purpose of this study was to investigate electromyographic activities of the flexor digitorum superficialis (FDS) and the flexor carpi ulnaris (FCU) by the shape of the ultrasound head. Twelve healthy subjects participated and performed ultrasound therapy with a round head and a long handled head during each 5-minute application. Electromyographic activities of the FDS and FCU were recorded by surface electrodes and normalized by maximal voluntary isometric contraction (MVIC) values. There was no difference in the muscular fatigue of FDS and FCU as determined by the shape of the ultrasound head (p>.05). Without the shape of head, the mean power frequency decreased with the time. There also was no difference in %MVIC of the FDS and FCU as determined by the shape of the ultrasound head (p>.05), but the force exerted exceeded 20%MVIC. There was however a significant difference in the amount of cumulative workload of the FDS and FCU as determined by the shape of ultrasound head (p<.05). The workload was however not affected by the shape of the ultrasound head. Constant static grasp of ultrasound transducer head during ultrasound therapy is considered a high risk factor of work-related musculoskeletal disease.