• 대한물리의학회지
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• 제4권4호
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• pp.209-214
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• 2009

Purpose：The purpose of this study are analysis characteristic of grasping power with each different elbow flexion degree and grasping power with each different elbow each different hand position and announcement. Methods：Measuring about 10cm wide open position with both feet for each elbow in the line positions of the $0^{\circ}$, $45^{\circ}$, $90^{\circ}$, $135^{\circ}$, and forearm position of supination, mid position, pronation is of the order. Results：The averge position of maximal grip strength was $0^{\circ}$ of elbow flexion with mid position in male and $90^{\circ}$ of elbow flexion with mid position in female. Grip strength in change of wrist position according to elbow flexion was significant difference(P<0.05). Grip strength in change of wrist position according to elbow flexion by sex was significant difference(P<0.05) Conclusion：When the elbow has flexion with $0^{\circ}$, $45^{\circ}$, $90^{\circ}$, $135^{\circ}$ then grasping power has a intimate relation with forearm position. Grasping power with forearm supination, pronation and mid position also has a intimate relation with elbow flexion.

• The Journal of Korean Physical Therapy
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• 제35권5호
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• pp.151-155
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• 2023

Purpose: This study examined the effect of the degree of neck flexion on the muscle activity of the upper trapezius and sternocleidomastoid muscles in the sitting position. Methods: Twenty-five healthy young adults participated in this study. The study was designed to compare the muscle activity of the upper trapezius and sternocleidomastoid muscles according to the neck flexion angle under the three conditions (neutral position, 15° neck flexion, and 45° neck flexion) in the sitting position. During the neck position of three conditions in sitting, the electromyography (EMG) data (% maximum voluntary isometric contraction) of the muscles were recorded using a wireless surface EMG system. Results: The muscle activity of the upper trapezius muscle and the sternocleidomastoid muscles showed a significant difference according to the three-neck position conditions (p<0.05), and in the post-hoc test results, both muscles showed significant differences between the neutral position and 15° flexion, the neutral position and 45° flexion, and the 15° flexion and 45° flexion, respectively. Conclusion: The load on the muscles around the neck and shoulders increased as the neck flexion angle increased. This suggests that performing various daily activities and tasks with the neck as neutral as possible can prevent muscle fatigue or musculoskeletal disorders.

• 한국전문물리치료학회지
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• 제26권3호
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• pp.91-98
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• 2019

Background: The bridge exercise targets the gluteus maximus (Gmax) and gluteus medius (Gmed). However, there is also a risk of dominant hamstring (HAM) and erector spinae (ES) muscles. Objects: To analyze the muscle activity the of Gmax, Gmed, HAM and ES during the bridge exercise with and without hip external rotation in different degrees of knee flexion. Methods: Twenty-three subjects were participated. The electormyography (EMG) activity of the Gmax, Gmed, HAM and ES muscles was recorded during the exercise. The subjects performed the bridge exercise under four different conditions: (a) with $90^{\circ}$ knee flexion, without hip external rotation (b) with $90^{\circ}$ knee flexion, with hip external rotation (c) with $135^{\circ}$ knee flexion, without hip external rotation (d) with $135^{\circ}$ knee flexion, with hip external rotation. Results: There was no significant interaction effect between the degree of knee flexion and hip external rotation. There was a significant main effect for degree of knee flexion in Gmax, HAM muscles activity. Gmax muscle activity was significantly greater in the $135^{\circ}$ knee flexion position than in the $90^{\circ}$ knee flexion position (p<.001). While HAM muscle activity was significantly less in $135^{\circ}$ knee flexion position than in the $90^{\circ}$ knee flexion position (p<.001). ES muscle activity was significantly less in the $135^{\circ}$ knee flexion position than in the $90^{\circ}$ knee flexion position (p=.002). The activity of both the Gmax and Gmed muscles was significantly greater with hip external rotation (p<.001 and p=.005, respectively). Conclusion: For patients performing the bridge exercise, positioning the knee in $135^{\circ}$ of flexion with hip external rotation is effective for improving Gmax and Gmed muscle activity while decreasing HAM, and ES muscle activity.

• 대한물리의학회지
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• 제16권1호
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• pp.9-16
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• 2021

PURPOSE: This study was to investigate the effect of applying neck flexion during elbow flexion exercise on muscle activity of the biceps brachii, the anterior deltoid and the sternocleidomastoid (SCM). METHODS: Twenty healthy adults participated in this study. The subjects measured %MVIC (Maximal volumetric control) and collected the maximum electromyography (EMG) values in the biceps brachii, anterior deltoid, SCM. The first action was to sit in a sitting position with the eyes facing front and maintained the weight of each section by performing elbow flexion using a tension gauge. The second action was to sit in a sitting position with the head down and maintained the weight of each section by performing elbow flexion using a tension gauge. Paired T-test was used for comparison of the before-and-after neck flexion to analyze the muscle activity of the Biceps brachii of next flexion and extension, the SCM, and the Anterior deltoid during elbow flexion exercise. The Repeated measured ANOVA was used for comparing %MVIC in each muscle. The significance level (?) was set at .05. RESULTS: Neck flexion during elbow flexion increased the muscle activity of the Biceps brachii and Anterior Deltoid muscle in the maximal muscle strength 50 ~ 60%, 70 ~ 80% and decreased the muscle activity of the SCM (p < .05). CONCLUSION: The applic has been confirmed to reduce the mobilization of the SCM and increase the mobilization of the Biceps brachii and Anterior Deltoid to increase the mobilization. Therefore, it seems effective to apply neck flexion when elbow flexion exercise.

• 대한물리의학회지
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• 제11권3호
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• pp.35-39
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• 2016

PURPOSE: The purpose of this study was to examine changes in the neck flexion angle according to posture while using a smartphone and the duration of smartphone usage. METHODS: The subjects in this study were 16 healthy young students in their 20s. The subjects wore a cervical range of motion instrument. They were instructed to use a smartphone while standing, sitting on a chair, and sitting on the floor. In all postures, they could use the smartphone and use their arms freely while keeping their back connected to the wall or the back of the chair. When sitting on the floor, they assumed a cross-legged position. The neck flexion angle was measured at zero, three, six, and nine minutes for each posture. RESULTS: Neck flexion is affected by the posture while using a smartphone (p<.05). Neck flexion in the standing position is larger than that in the sitting on the floor position. Neck flexion was affected by smartphone usage duration (p<.05). In general, as usage time increases, the neck flexion angle increases as well. CONCLUSION: This study suggests that using smartphone in the standing position and for a short period of time is a method to reduce the neck flexion angle.

• Journal of Oral Medicine and Pain
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• 제20권2호
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• pp.489-496
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• 1995

The purpose of this study was to evaluate an effect of change on head posture initial occlusal contacts with measuring the distances between initial occlusal contacts and maximum intercuspal position at different head posture in TMDs patient. For this study, 24 patients from age 13 to 36 were selected, they were examined health history taken, patients who have sign and symptoms of TMDs were examine before the study. For the normal group, 21 adults from age 23 to 25 were selected. They have normal or class I molar relationship, and have no other prosthetic restorations. Difference on distance between initial occlusal contact and maximum intercuspal position with mandibular kinesiograph$(MKG^R)$(K6 diagnostic system, Myo-tronic Inc, USA) in upright, supine, 45$^{\circ}$ extension, 30$^{\circ}$ flexion position of the head were measured. The Frankfort horizontal plane was used as a reference plane. The results were as follows : 1. There were significant differences between initial occlusal contacts of the normal and patient group on upright position and 30$^{\circ}$ flexion of the head(p<0.05, p<0.01) 2. The position of the initial occlusal contacts have a tendency to place anterior and inferior to maximal intercuspal position in upright position and 30( flexion of the head as well as posterior and inferior in supine position and 45$^{\circ}$ extension of the head in the normal and patient groups. 3. There were significant differences among the initial occlusal contacts between uptight and supine position; upright and 45$^{\circ}$ extension of the head(p<0.05); supine position and 30$^{\circ}$ flexion of the head, .and 30(flexion and 45$^{\circ}$ extension of the head in the patient group(p<0.01) The result have shown that after treatment on the supine position, it may be necessary to check occlusal contact on the upright position as well ass flexion of the head. It may need careful adjustment in occlusal condition on upright position of TMDs patient.

• 대한통합의학회지
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• 제7권4호
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• pp.33-41
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• 2019

Purpose : The muscle strength of iliopsoas (IL) was measured commonly in sitting position with hip and knee flexed 90°. However, there is no study to determine the muscle strength of IL in various test positions. Therefore, the purpose of this study was to compare the muscle strength of IL and muscle activity of rectus femoris (RF) according to test position and knee flexion angle. Methods : Twenty healthy subjects were participated for this study. The muscle strength of IL and muscle activity of RF were measured by hand-held dynamometer and surface electromyography during maximum voluntary isometric contraction (MVIC) of IL, respectively. The muscle strength of IL and muscle activity of RF was measured in 4 conditions as follows; 1) knee flexion angles 90 ° in supine, 2) 130 ° in supine position, 3) 90 ° in sitting, 4) 130 ° in sitting. Each condition were performed randomly by three repetitions. Results : The muscle strength of the IL was the main effect on the test position and knee flexion angle (p<.05), and the muscle activity of RF was the main effect only on the knee flexion angle (p<.05). There was also no interaction between the factors (p>.05). In supine position, the muscle strength of IL in knee flexion 130 ° was significantly less than that in knee flexion 90 ° (p<.0125). In knee flexion 90 °, the muscle strength of IL in supine position was significantly greater than that in sitting position (p<.0125). The muscle activity of RF in knee flexion 130 ° was significantly less than that in knee flexion 90 ° in supine and sitting positions (p<.0125). Conclusion : When the muscle strength of IL was measured in clinic and sports fields, the supine position with knee flexion 130 ° was recommended to prevent the muscle activation of RF and to maintain the trunk stability.

• 한국전문물리치료학회지
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• 제29권1호
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• pp.79-86
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• 2022

Background: Bird dog exercise (BDE) is one of the lumbar stabilization exercises that rehabilitate low back pain by co-contraction of the local and global muscles. Previous studies have reported the effect of various type of BDEs (for example, practicing the exercises on various surfaces and changing the limb movement) for muscle co-contraction. Objects: This study aimed to investigate the effect of knee joint flexion position of the raised lower limb on abdominal and back muscle activity during BDE in patients with chronic low back pain (CLBP). Methods: Thirteen males participated in this study (age: 32.54 ± 4.48 years, height: 177.38 ± 7.17 cm). Surface electromyographic (SEMG) data of the internal abdominal oblique (IO), external abdominal oblique (EO), lumbar multifidus (MF), and thoracic part of the iliocostalis lumborum (ICLT) were collected in two knee joint flexion positions (90° flexion versus 0° flexion) during BDE. The SEMG data were expressed as a percentage of root mean square mean values obtained in the maximal voluntary isometric contraction. Results: Greater muscle activity of the IO (p = 0.001), MF (p = 0.009), and ICLT (p = 0.021) of the raised lower limb side and the EO (p = 0.001) and MF (p = 0.009) of the contralateral side were demonstrated in the knee joint flexion position compared to the knee joint extension position. Greater local/global activity ratios of the abdominal muscle (i.e., IO and EO) of the raised lower limb (p = 0.002) and the back muscle (i.e., MF and ICLT) of the contralateral side (p = 0.028) were also noted in the knee joint flexion position. Conclusion: BDE with a knee joint flexion position might be recommended as an alternative lumbar stabilization exercise to enhance muscle activity in both the raised lower limb and the contralateral sides of the trunk for individuals with CLBP.

• The Journal of Korean Physical Therapy
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• 제7권1호
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• pp.43-49
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• 1995

The purpose of this study were to determine the effect of testing posture and elbow position on grip strength. Two hundred college students 100 males and 100 females aged 18 to 28 years, participated in the study. A Grip-Strength Dynamometer was used to measure the grip strength in two testing posture(sitting and standin) and four elbow position$(0^{\circ},\;45^{\circ},\;90^{\circ}\;and\;135^{\circ}\;flexion)$ correlations and t-test was used to determine any significant difference in grip strength between the testing posture and the elbow position. The results were as follows : 1. The grip strength was affected by testing pasture and flexion degree of elbow. 2. The grip strength was stronger in the standing than sitting in subjects 3. The grip strength decreased according to elbow flexion increase in subjects. 4. The higher grip strength gained in the standing with the elbow 0 flexion. 5. The grip strength by elbow flexion degree showed significant difference at sitting and standing posture. The grip strength was significant differenced by testing position at same elbow flexion degree.

• 대한물리치료과학회지
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• 제20권1호
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• pp.43-49
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• 2013

Background and purpose : The shoulder joints permit the greatest mobility of any joint area carries out the important function of stabilization for hand use. Research has now shown that grip strength has proven to be a reliable indicator for quality of life at an older age. The purpose of this study was to investigate the effects of testing posture and shoulder position on grip strength for repetitive gripping task. Methods : Forty(20male, 20female) college adult volunteers with no known shoulder dysfunction participated subject in two testing posture(sitting and standing) and three positions with shoulder flexion: (1) shoulder $0^{\circ}$ flexion (2) shoulder $90^{\circ}$ flexion (3) shoulder $180^{\circ}$ flexion. The paired t-test was used to determine any significant difference in grip strength between the testing posture and shoulder position. Results : The higher grip strength gained in the sitting with the shoulder $180^{\circ}$ flexion and the higher grip strength gained in the standing with the shoulder $180^{\circ}$ flexion. The second experiment showed that the grip strength was significant for sitting, standing position of shoulder $0^{\circ}$ flexion( p<0.05). Grip strength goes up as increase height and weight. Conclusion : These findings demonstrate that the theory does not fit with, because of the influence of gravity, a measure from the shoulder joint is the most high, $0^{\circ}$. And sitting posture and stance in the grip of a difference when compared SIT $0^{\circ}$ and standing position $0^{\circ}$ significant difference in indicated but, $90^{\circ}$ and $180^{\circ}$ in the sitting position and stance in the grip of the difference was not significant difference. To demonstrate the universality of this study's results, future studies should have a larger and more subject as well as a more even distribution of male and female subject. Therefore future research is needed to refine the definition and identify optimal methods of measuring this grip strength.