본 연구는 EMG(electromyography) 텍스타일 전극 개발을 목적으로 레이어 수의 디자인 및 원단을 다르게 하여 성능 및 신호 획득 안정성을 평가한다. 레이징 및 프레스 공정을 통하여 텍스타일 전극을 제조하며 Layer-0, Layer-1, Layer-2로 레이어 유무 및 수에 따른 결과를 분석했다. 이에 레이어 유무에 따라서는 근활성 측정에 영향을, 수가 많을수록 높은 성능이 나타남을 확인할 수 있었다. Layer-2 구조로 통일하여 5가지의 원단(네오프렌, 스판덱스 쿠션, 폴리에스테르 100%, 나일론 스판덱스, 광목 캔버스)으로 전극을 제조해 실험해 보았다. 성능적인 면에서, 원단의 중 량이 높은 나일론 스판덱스가 높은 성능을 보였으며, 스판쿠션 텍스타일 전극이 근활성도 수득에 높은 안정성을 보 였다. 이에 위 연구는 레이어에 따른 성능 연관성과 전극-피부사이의 닿는 면적 간의 관계 등을 고찰하여 슬리브 전체의 의복압을 늘리는 대신 특정 센서 측정 부위에만 높은 압력을 가함으로 차후 연구에서 레이어의 수 및 물성에 따른 전극의 공학적 설계 가능성을 제시한 의의가 있다.

Background: The Nordic hamstring exercise is a closed-chain exercise that effectively activates all lower extremity muscles, but there is a lack of consideration of ankle joint which affects exercise effectiveness. One of the major advantages of the Nordic exercise have been known as strengthening lower extremity extensors. This manifests the exercise increases activities of the ankle plantar flexors as well as hip extensors. Objectives: To investigated the impacts of changes in ankle position on the lower extremity musculature and subjective difficulties during the Nordic hip extension exercise. Design: Cross-sectional study. Methods: Twenty the healthy male participants participated in this study. Participants perform three variations of the Nordic exercises including three ankle positions. Each Nordic exercise was defined as ankle position (neutral, dorsiflexion and plantar flexion). During the Nordic exercise, erector spine (ES), gluteus maximus (GM), biceps femoris (BF), gastrocnemius (GCM) activities and subjective difficulties (Borg RPE score) were measured. Results: Muscular activities of the biceps femoris and gastrocnemius were significantly different among the three ankle conditions, which showed controversial results (P<.05). The biceps femoris activity was significantly higher with the dorsiflexion condition, compared to the others (P<.05). On the other hand, activity of the gastrocnemius was significantly higher with the plantarflexion position compared to the others (P<.05). Conclusion: Present study suggests the ankle positional changes could affect lower muscular activities during the Nordic exercise. Although it is difficult to affirm the causes due to limited data, selective activation of the biceps femoris might accomplish with ankle dorsi flexion and that of the gastrocnemius might accomplish with the ankle plantarflexion during the Nordic exercises.

본 연구의 목적은 정적 플랭크 운동의 동작 차이에 따른 코어근육의 근활성도를 비교하는 것이 었다. 본 연구의 대상자는 “J”대학교 20대 남성 10명을 대상으로 진행하였고(연령, 23.20±0.65 세; 신장, 174.54±1.51 cm; 체중, 70.00±2.24 kg; 신체질량지수, 22.94±0.51 kg/m2), 4가지의 풀, 엘보우, 사이드 및 리버스 정적 플랭크 동작을 수행하였으며, 근전도 분석을 위한 표면전극 부착 부위는 신체 근육의 우측 복직근, 외복사근, 광배근 및 척추기립근으로 설정하였다. 본 실험 결과, 광배근과 척추기립근의 근활성도 는 리버스 플랭크 동작 시 가장 높게 나타났고(p<.001), 복직근과 외복사근의 근활성도는 엘보우 플랭크 동작 시 가장 높게 나타났다(p<.001). 따라서 본 연구의 결과는 추후 정적 플랭크 동작 시 효과적인 운동 프로그램의 자료가 될 것으로 기대된다.

Background: The hamstring muscles in the lower extremity are highly important for knee joint stability and can be classified into medial and lateral hamstrings according to the anatomical position, which have some different functions. To measure the strength of the individual hamstring muscles, manual muscle testing is clinically performed by dividing rotation postures into internal and external postures. However, this has no sufficient scientific background. Objects: This study aimed to test the difference that the tibial rotation would cause in the muscle activity of the medial and lateral hamstrings. Methods: The muscle activities of the biceps femoris, semitendinosus, and semimembranosus were measured in a total of three different postures (neutral position and internal and external rotations) with 3 replications. During the maximal isometric contraction, resistance was constantly provided by the string attached to the strap, not by manual resistance of the examiner. Before and after electromyography measurements, the participants underwent hamstring flexibility measurement using the active knee extension test in the supine position on the treatment table Results: The semitendinosus had a 12.56% reduction in muscle activity in external rotation as compared with that in neutral position. The biceps femoris and semimembranosus showed reduced muscle activities in both external and internal rotations as compared with those in neutral position. Only the women showed significant decreases in the comparison between pre and post-active knee extension. Conclusion: Only the semitendinosus muscle was consistent with the anatomical speculation. However, the reduction in the muscle activity of the semitendinosus as compared with that in neutral position was only 12.56%, the clinical value of which may be difficult to justify.

본 연구는 스탠스 자세와 운동면의 차이가 어깨돌림동작 시 활동근의 %MVIC를 비교분석하여 어깨강화운동을 위한 기초자료를 제공하는데 목적이 있다. 남성 8명을 무선배정하여 두발지지 자세, 한발지지 자세, 런지자세와 이마면, 수평면, 시상면에서 회전동작을 10회씩 수행하였다. 수행 중 가시위근, 가시아래근, 작은원근, 앞세모근, 배곧은근, 척수세움근, 큰가슴근, 넓은등근의 근활성도를 측정하였다. SPSS 22.0 통계프로그램을 사용하여 반복측정 일원분산분석(repeted one-way ANOVA)을 실시하였다. 첫째, 이마면에서 바깥돌림 동작 시 척추세움근은 두발지지 자세와 한발지지 자세보다 런지자세에서 높게 나타났고 안쪽돌림 동작 시 가시위근은 두발지지 자세보다 한발지지 자세, 한발지지 자세보다 런지자세에서 높게 나타났다. 둘째, 수평면에서 바깥돌림 동작 시 앞세모근은 두발지지 자세보다 한발지지 자세과 런지자세에서 높게 나타났고 안쪽돌림 동작 시 가시아래근은 두발지지 자세와 한발지지 자세보다 런지자세에서 높게 나타났으며, 큰가슴근에서는 한발지지 자세보다 두발지지 자세, 한발지지 자세보다 런지자세가 높게 나타났다. 셋째, 시상면 바깥돌림 동작 시 배곧은근은 두발지지 자세보다 한발지지 자세와 런지자세에서 유의하게 높게 나타났다. 안쪽돌림 동작 시 가시위근은 두발지지 자세보다 한발지지 자세와 런지자세에서 높게 나타났고 가시아래근은 두발지지 자세와 한발지지 자세보다 런지자 세에서 높게 나타났다. 배곧은근에서 두발지지 자세와 런지자세보다 한발지지 자세에서 높게 나타났고 척추세움근은 한발지지 자세보다 두발지지 자세와 런지자세에서 높게 나타났다. 결론적으로 스탠스와 어깨의 운동면의 차이가 어깨위팔관절의 돌림운동 시 활동근들의 근활성도에 미치는 영향은 스탠스자세와 운동면에 따라서 다른 양상이 나타났으며, 이를 어깨 강화 운동프로그램에 적용한다면 보다 긍정적 효과를 기대할 수 있는 운동프로그램이 될 것으로 생각 된다.

본 연구는 필라테스 동작 시 폼롤러의 적용과 움직임에 따른 몸통과 하지의 근활성도 차이를 알아보는 것이 목적이다. 피험자로 남자 8명을 선정하여 필라테스 네발자세, 교각자세, 코어컨트롤 동작을 매트위에서 정적동작, 폼롤러 위에서 정적동작, 폼롤러 위에서 동적동작으로 무선배정하여 1주 간격으로 수행하였다. 각 동작의 수행 시 척추세움근, 배곧은근, 배바깥빗근, 중간볼기근, 넙다리두갈래근과 넙다리곧은근의 근활성도를 측정하여 일원분산분석으로 분석하였다. 유의수준은 α=.05로 설정하였다. 첫째, 네발기기 동작에서 폼롤러 동적동작에서는 배곧은근, 배바깥빗근, 중간볼기근, 넙다리두갈래근의 근활성도가 높게 나타났으며(p<.001)(p<.05), 폼롤러 정적동작에서는 넙다리곧은근의 근활성도가 높게 나타났다(p<.001). 둘째, 교각자세 동작에서 폼롤러 동적동작에서는 넙다리두갈래근의 근활성도가 높 나타났다(p<.001). 셋째, 코어컨트롤 동작에서 폼롤러 동적 동작에서는 배곧은근, 척추세움근, 중간볼기근의 근활성도가 높게 나타났으며(p<.001)(p<.01), 정적 동작에서는 배바깥빗근의 근활성도가 높게 나타났다(p<.05). 필라테스 운동시 근활성도를 고려하여 방법과 난이도를 적용하면 더욱더 효과적일 것이라 사료된다.

Various studies related to therapeutic horseback riding have been reported to be positive for the therapeutic effect of patients with cerebral palsy; however, most of the previous studies focused on to muscle development with training period related to the physical effects of therapeutic horseback riding. To identify the causes and phenomena of muscular activation of the body through actual therapeutic horseback riding exercise and to promote the excellence of physical effects of therapeutic horseback riding. This study was a nonrandomized prospective positive-controlled trial design. Twelve teenaged males with cerebral palsy were selected who had experienced riding exercise for 8-12 months. This study measured 8 muscle activities of the pectoralis major muscle (PM), biceps brachii (BB), rectus abdominis muscle (RA), latissimus dorsi muscle (LD), spinal erector muscle (SE), rectus femoris muscle (RF), anterior tibial muscle (AT), and external gastrocnemius muscle (EG) by using electromyography (EMG). Muscle activity was significantly higher in horse riding position than sitting on the common chair in all muscles (PM, BB, RA, LD, SE, RF, AT, and EG). The activity of the body muscles according to the difference of horse walking method (walk: WA; sitting trot: ST; and riding trot: RT) of therapeutic horse riding showed the highest muscle activity in the PM muscle at ST, and the highest activity at BB, RA, LD, SE, and AT muscles at ST and RT, and showed the highest muscle activity in RF and EG muscle at RT. The results of this study suggest that intervention for the treatment of cerebral palsy patients can use therapeutic riding exercise as a rehabilitation method.

Background: Scapular downward rotation syndrome (SDRS) is a common scapular alignment impairment that causes insufficient upward rotation and muscle imbalance, shortened levator scapulae (LS) and rhomboid, and lengthened serratus anterior (SA) and trapezius. A modified shrug exercise (MSE), performing a shrug exercise with the shoulders at 150° abduction, is known as an effective exercise to increase scapular stabilizer muscle activation. Previous studies revealed that scapular exercise are more effective when combined with trunk stabilization exercises in decreasing scapular winging and increasing scapular stabilizer muscle activation. Objects: The purpose of our study was to clarify the effect of MSE with or without trunk stabilization exercises in subjects with SDRS. Methods: Eighteen volunteer subjects (male=10, female=8) with SDRS were recruited for this experiment. All subjects performed MSE under 3 different conditions: (1) MSE, (2) MSE with an abdominal draw-in maneuver (ADIM), and (3) MSE with an abdominal expansion maneuver (AEM). The muscle thickness of the lower trapezius (LT) and the SA were measured using an ultrasonography in each condition. Electromyography (EMG) data were collected from the LT, LS, SA, and upper trapezius (UT) muscle activities. Data were statistically analysed using one-way repeated analysis of variance at a significance level of .05. Results: The muscle thickness of the LT and the SA were the significant different in the MSE, MSE with ADIM (MSE+ADIM) and MSE with AEM (MSE+AEM) conditions (p<.05) In both LT and SA, the order of thick muscle thickness was MSE+AEM, MSE+ADIM, and MSE alone. No significant differences were found in the EMG activities of the SA, UT, LS, and LT in all condition. Conclusion: In conclusion, MSE is more beneficial to people with SDRS when combined with trunk stabilization exercises by increased thickness of scapular stabilizer muscles.

Background: The MLA is supported by both the abductor hallucis (ABH) and the extrinsic muscles. Insufficient muscular support may lower the MLA when the body’s weight is applied to the foot. The short foot exercise (SFE) is effective in increasing the height of the MLA for people with flat feet. Most of the research related to the SFE has simply evaluated the efficiency of the exercise using enhanced ABH electromyography (EMG) activation. Since the tibialis anterior (TA), peroneus longus (PER), and ABH are all involved in supporting the MLA, a new experiment design examining the EMG of the selected muscles during SFE should be applied to clarify its effect. Objects: Therefore, this study aimed to clarify the effect of the SFE in different ankle position on the MLA angle and the activation of both the intrinsic and extrinsic muscles and to determine the optimal position. Methods: 20 healthy subjects and 12 subjects with flat feet were recruited from Yonsei University. The surface EMG and camera were used to collect muscle activation amplitude of TA, PER, and ABH and to capture the image of MLA angle during SFE. The subjects performed the SFE while sitting in three different ankle positions—neutral (N), dorsiflexion (DF) at 30 degrees, and plantar flexion (PF) at 30 degrees. Results: ABH EMG amplitudes were significantly greater in N and DF than in PF (p<.05). Muscle activation ratio of TA to ABH was the lowest in PF (p<.05). MLA angle in both groups significantly decreased in PF (p<.01). The TA and ABH was activated at the highest level in DF. However, in PF, subjects significantly activated the ABH and PER with relatively low activation of TA. Conclusion: Therefore, researchers need to discuss which SFE condition most effectively use the arch support muscle for flat foot.

The purpose of this study was to examine the effects of abdominal hollowing with ultrasound biofeedback on multifidus and transversus abdominis/internal oblique muscle activities during lifting tasks. This study recruited 12 healthy men. All subjects received training on expiration without and with abdominal hollowing with ultrasound biofeedback. After receiving training for each condition, the thickness of transversus abdominis was measured using ultrasound, and then, electromyography activities of transversus abdominis/internal oblique and multifidus during lifting tasks were measured using a surface electromyography system. The differences in thickness of transversus abdominis and electromyography activities of transversus abdominis/ internal oblique and multifidus between the two conditions were analyzed using paired t-test. Thickness of transversus abdominis and transversus abdominis/internal oblique and multifidus activities were significantly increased during expiration with abdominal hollowing with ultrasound biofeedback compared to during expiration without abdominal hollowing (p < 0.05). These findings suggest that abdominal hollowing with ultrasound biofeedback is effective in increasing trunk stabilizer muscle activities during both static and dynamic tasks such as lifting.

The purpose of this study was to investigate the effects of stable and unstable bridging exercises on the EMG activity of abdominal muscles. Twenty healthy women participated in this study and the muscle activities of left-right rectus abdominis (RA), external oblique (EO), and internal oblique (IO) muscles were recorded during 4 bridging exercises (unilateral/ bilateral, stable/unstable). The activity of the right EO muscle was the highest during unilateral exercise in unstable condition, and left EO muscle also produced the same result. The activity of the right IO muscle was the highest during unilateral exercise in an unstable condition, and left IO muscle also produced the same result. The activity of the right RA muscle was the highest during unilateral exercise in a stable condition, and left RA muscle produced the same result. Unstable/unilateral (USUL) represented the highest activity among the 4 exercises. EO/IO muscles represented the highest activity during the USUL exercise, and RA did so during the stable/unilateral exercise. These results suggest that specific posture (USUL) can be administered targeting a specific side of abdominal muscles.

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 α=.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.

Background: Recently, there has been an emphasis on the use of interventions with biofeedback information for the maintenance or correction of posture. Objects: This study assessed the change of trunk posture and trunk muscle activation when people exhibiting postural kyphosis performed visual display terminal work with or without a contact feedback device (CFD). Methods: Eighteen right-handed individuals were recruited. Thoracic angle and right thoracic erector spinae (TES) muscle amplitude were analyzed. There were two sessions in these experiments. The control session involved 16 minutes of typing without a CFD, and the CFD session involved 16 minutes of typing with a CFD. The visual analog scale score was analyzed with a paired t-test, and the kinematic and electromyography data were analyzed through two-way repeated analysis of variance. Results: The paired t-tests revealed that subjects had significantly less pain after the CFD sessions than after the control sessions (p<.05). Significant main effects by session and by time were observed in the thoracic kyphosis angle (p<.05). There was a significant session×time interaction for TES amplitude (p<.05), along with significant main effects by session and by time (p<.05). Conclusion: The CFD caused people with postural kyphosis to straighten and to activate their TES continuously, even though they were habituated to bend their bodies forward. Therefore, the CFD was a beneficial treatment tool

뇌와 근육은 상의 하달식 구조로 상지 운동 수행 과정에서 뇌파와 근전도 신호의 변화와 함께 기능적 연결성이 발생한다. 본 논문에서는 사용자가 상지 운동을 수행하였을 때의 뇌파와 근전도 신호에 대해 코히어런스 방법을 적용하 여 운동 의도 여부에 따른 뇌와 근육간의 연결성 차이를 규명하고자 한다. 상지 운동을 수행하는 과정에서 운동 피질 영역의 뇌파는 뮤 리듬(mu rhythm, 8~14 Hz)과 베타 리듬(beta rhythm, 15~30 Hz)에서 활성화 되며, 근전도 신호는 베타 리듬과 파이퍼 리듬(piper rhythm, 30~60 Hz)에서 활성화 된다. 뇌파와 근전도 신호간의 코히어런스 분석 결과 운동 의도를 포함한 능동 운동 수행 시 수동 운동을 수행하였을 때 보다 유의미한 차이로 높은 코히어런스 계수가 확인되었다. 이는 인지적 반응과 근육의 움직임 사이의 코히어런스 관계로 운동 의도가 포함된 상지 운동 수행 과정에서 의 뇌와 근육간의 연결성을 해석할 수 있었다. 운동 의도에 따른 뇌-근육간의 코히어런스 특징을 이용한다면 재활 기기 사용자의 운동 의도에 따라 피드백이 필요한 재활 훈련 시스템 설계에 도움이 될 수 있을 것으로 사료된다.

Background: Prone hip extension (PHE) can be performed to measure the lumbopelvic motor patterns and motions. Imbalances in lumbopelvic muscle activity and muscle weakness can result in instability including pain in lumbopelvic region. The posterior oblique sling (POS) muscles contribute to dynamic lumbopelvic stability. In addition, POS are anatomically aligned with the trapezius muscle group according to shoulder positions. Objects: This study compared the electromyography (EMG) activity of POS and pelvic compensations during PHE with and without pre-activation of lower trapezius muscle (lowT). Methods: Sixteen healthy males were recruited. PHE was performed in randomized order: PHE with and without lowT pre-activation. Surface EMG signals were recorded for biceps femoris (BF), gluteus maximus (GM) (ipsilateral), lumbar multifidus (MF) (bilateral), and the lowT (contralateral). An electromagnetic tracking motion analysis was used to measure the angle of pelvic rotation and anterior tilting. Results: The ipsilateral GM and bilateral MF EMG amplitudes were greater during PHE with lowT pre-activation compared to PHE without lowT pre-activation (p<.05). The BF amplitude during PHE without lowT pre-activation was significantly greater than that during PHE with lowT pre-activation (p<.05). The angles of pelvic rotation and anterior tilting during PHE with lowT pre-activation were significantly smaller compared to PHE without lowT pre-activation (p<.05). Conclusion: PHE with lowT pre-activation, which is aligned with the POS, showed more increased MF and GM muscular activity with smaller lumbopelvic compensations in rotation and anterior tilting compared to PHE without lowT pre-activation.

Lumbopelvic stabilization exercise has become the most popular treatment method in lumbar rehabilitation since its effectiveness was shown in some aspects of pain and disability. The abdominal drawing-in maneuver (ADIM) has been extensively implemented to promote lumbopelvic stability. However, performing ADIM correctly is difficult even for healthy subjects, and it is time consuming to train people in ADIM. Thus, the purpose of this study was to compare abdominal muscle [rectus abdominalis (RA), external oblique (EO), and transverse abdominis/internal oblique (TrA/IO)] activity during lumbopelvic stabilization exercises (ADIM only, ADIM with a ball, maximum exhalation only, and maximum exhalation with a ball) performed in a supine position with feet against a wall. Fifteen healthy subjects were recruited for this study. Surface electromyography was used to measure abdominal muscle activity during lumbopelvic stabilization exercises. A one-way repeated-measures analysis of variance was used to determine the statistical significance of RA, EO, and TrA/IO muscle activity during four lumbopelvic stabilization exercises. Both-side TrA/IO muscle activity was significantly greater with maximum exhalation with a ball than with ADIM only or ADIM with a ball (p<.008). The results of this study suggest that maximum exhalation with a ball can be used as an effective lumbopelvic stabilization exercise to increase TrA/IO muscle activity in healthy subjects.

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.