• PNF and Movement
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• 제19권1호
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• pp.127-135
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• 2021

Purpose: The purpose of this study was to determine the effect of the side-bridge exercise on the thicknesses of the external and internal obliques, the transverse abdominis, and the erector spinae, which are some of the trunk muscles of healthy adult males and females. Methods: There were 30 subjects divided into two groups with 15 subjects in the modified side-bridge exercise group and 15 subjects in the bridge exercise group. The changes in each variable were analyzed before the exercise, after three weeks, and after six weeks of exercise using a two-way repeated analysis of variance. The significance level was set at 0.05. When there was any interaction between the time of measurement and each group, a paired t-test was conducted to find the difference within groups and an independent-sample t-test was conducted to find the difference between groups. The significance level for both tests was set at 0.01. Results: There was a significant difference in the external and internal obliques and the erector spinae according to changes over time and the interactions between the time and groups (p < 0.05). However, there was a significant difference in the transverse abdominis only according to the interaction between the length of times (p < 0.05). Conclusion: The study results indicated that the modified side-bridge exercise significantly increased the thickness of the external and internal obliques and the erector spinae. This suggests the usability of the exercise in lumbar stabilization exercises in future studies and clinical fields.

• 정형스포츠물리치료학회지
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• 제14권2호
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• pp.55-64
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• 2018

Purpose : The purpose of this study was to investigate the effect of the sprinter and skater combined patterns on muscle contraction onset time and muscle activation of body stabilizing muscles. Method : Our study included young and healthy men in their 20s. The participants used the sprinter and skater combined patterns of the proprioceptive neuromuscular facilitation (PNF) methods to measure muscle activation and muscle contraction onset time of the trunk muscles. To measure muscle contraction onset time and muscle activation, electrodes were attached to the rectus abdominis (RA), external oblique (EO), internal oblique (IO), and erector spinalis (ES) regions. Significant differences were identified using a paired t-test and a one-way analysis of variance (ANOVA) analysis. Result : In the sprinter combined pattern, the muscle with the fastest onset time of contraction was the RES, and that with the slowest was the RRA (p<.001). In the skater combined pattern, the muscle with the fastest onset time of contraction was the LES, and that with the slowest was the LRA (p<.001). In the sprinter combined pattern, the REO and LIO presented medium muscle contraction onset times (p<.001). In the skater combined pattern, the LEO and RIO presented medium muscle contraction onset times (p<.001). Conclusions: Based on these results, these patterns could be used as exercise methods for the elderly with delayed proactive response speeds of the body stabilization methods due to imbalances in body stabilizing muscles or limbs movement.

• 한국체육학회지인문사회과학편
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• 제53권2호
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• pp.531-540
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• 2014

본 연구는 두 종류의 공기주입식 카약 보트의 성능 비교와 함께 선수들의 카약 전방 스트로크 동작의 차이점을 비교 분석하여 보다 효율적이고 안전한 카약 보트를 찾는 데 목적이 있다. 이를 위해 대한 체육회 소속 K 고등학교 엘리트 남자 선수 5명이 연구에 참여하였으며, K고 실내 수영장에서 실험을 실시하였다. 보트의 성능 평가를 위해 보트 속도, 보트 좌우 흔들림 각도 차이, 보트의 회전 평균 각속도를 산출하였으며 선수의 수행력 차이를 분석하기 위해 몸통의 회전 가동범위, 무릎 관절의 굴곡-신전 가동범위, 몸통의 최대 회전 각속도, 무릎관절의 최대 신전 각속도, 상하지 근육의 활성도를 산출하였다. 연구 결과 선수들의 수행력 평가 변인에서는 통계적으로 유의한 수치를 보이지 않았다. 보트의 성능 평가 변인에서는 보트의 속도에서 B보트가 통계적으로 유의하게 빨랐으며 다른 변인들은 통계적으로 유의한 차이를 보이지 않았다. 결국 길이가 상대적으로 길고 폭이 상대적으로 좁은 B보트는 A보트와 비교했을 때 비슷한 안전성을 갖고 있으면서 보다 효율성을 나타내었다.

• 한국융합학회논문지
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• 제10권3호
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• pp.67-72
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• 2019

본 연구는 일주일 동안의 컴퓨터 사용시간이 몸통 근육 두께와 압력 통증 역치에 미치는 영향을 분석하였다. 33명의 대상자를 일주일에 컴퓨터를 10시간 이하(A 그룹), 10시간에서 20시간(B 그룹), 20시간 이상 사용하는 그룹(C 그룹)으로 나누어 위 등세모근, 작은가슴근, 앞 목갈비근, 중간 목갈비근의 근 두께와 위 등세모근, 작은가슴근, 앞 목갈비근, 중간 목갈비근, 어깨올림근의 압력 통증 역치를 측정하였다. 본 연구의 결과 C 그룹의 작은가슴근, 앞 목갈비근, 중간 목갈비근은 다른 그룹들의 근 두께에 비해 유의하게 증가되었고(p<.05) 위 등세모근, 앞 목갈비근, 작은가슴근, 어깨올림근의 압력통증역치는 다른 그룹들에 비해 유의하게 감소하였다(p<.05). 그러므로, 본 연구는 1주일 동안 컴퓨터를 장시간 사용하는 사람들은 장시간 컴퓨터 사용이 다양한 근골격계 질환의 원인이 될 수 있음을 인지하고 그에 따른 적절한 예방적 접근을 수행할 것을 권장한다.

• 한국콘텐츠학회논문지
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• 제20권7호
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• pp.47-55
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• 2020

스마트 기기 사용의 증가와 함께 현대인들의 거북목 증후군 발병률이 증가했다. 거북목 증후군은 목의 앞 근육이 길어지고, 위쪽 근육이 짧아져 몸통에 비해 머리가 앞으로 나와 있는 자세이며, 수술이나 약물치료보다 평소의 자세 습관을 고치는 방법이 효과적이다. 따라서 본 논문에서는 실시간으로 거북목 증후군을 유발할 수 있는 자세를 감지하고 경고하는 시스템을 제안한다. 올바른 자세와 거북목 자세의 이미지 데이터들을 수집하여 합성곱 신경망기반의 학습모델을 만든다. 웹캠만을 이용하여 카메라에 들어오는 앉은 자세를 학습모델로 실시간 검증하고, 거북목 자세일 경우 경고음을 발생하여 바른 자세를 앉도록 유도한다. 이 시스템은 평소 자세 습관을 교정하도록 유도하여 거북목증후군을 치료하고 목 디스크와 같은 더 심각한 질병을 예방할 수 있다.

• 디지털융복합연구
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• 제12권12호
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• pp.441-447
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• 2014

본 연구는 대기업에 근무하는 산업체 근로자를 대상으로 비만도에 따른 척추안정화근력의 차이를 분석하는데 목적을 두었다. 편의표본 추출방법(Convenience Sampling Method)에 의하여 50명을 표본을 추출하여, 체질량지수(BMI) $25kg/m^2$ 이상을 비만군(25명), 이하를 정상군(25명)으로 분류하여 독립표본 t검정(Independent t-test)으로 분석하였다. 집단간 척추안정화근력의 측정결과 정상군의 평균이 비만군에 비해 모두 높았으며, Sagittal Plane에서는 $0^{\circ}$ Forward에서 유의한 차이를 보였고, Coronal plane에서는 $90^{\circ}$ Left, $90^{\circ}$ Right에서 유의한 차이를 보였으며, Diagonal Plane에서는 $45^{\circ}$ Left Tilt, $45^{\circ}$ Right Tilt에 유의한 차이를 보였다. BMI 분류에 따른 근육량과 골격근량의 분석결과에서는 비만군이 정상군에 비해 모두 높았으며 통계적으로 유의한 차이를 보였다. 비만군이 정상군에 비해 근육량은 많지만 척추안정화근력은 약하다는 것을 감안하여 Sagittal Plane, Coronal plane, Diagonal Plane에서의 비만인을 위한 척추안정화 강화 프로그램의 개발이 요구된다.

• 대한인간공학회지
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• 제25권2호
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• pp.197-204
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• 2006

The purpose of this study was to investigate the relationship between the cumulative fatigue of trunk muscles and the period of recovery time during repetitive lifting and lowering task with two different frequencies(4 times/min and 6 times/ min). Eight healthy males with no prior history of LBD(low back disorders) volunteered for this study. Subjects had 2, 3, 4, and 5 minutes recovery time respectively while they were preforming the lifting and lowering task at 15% level of MVC. EMG signals from six trunk muscles were collected and the fatigue level was analyzed quantitatively. In results, the fatigue levels of LES(left elector spinae), RLD(right lattissimus dorsi), LLD(left lattissimus dorsi), RRA(right rectus abdominis) and LRA(left rectus abdominis) were recovered when 3 minutes recovery time was given at 4 times/min frequency. However, the fatgue level of RES(right elector spinae) was recovered when 4 minutes recovery was given. On the other hand, when 6 times/min frequency was used, the RLD, LLD, RRA and LRA were recovered at 5 minutes of recovery time. But for RES and LES, it took longer than 5 minutes to be recovered. This results can be applied to design the adequate length of recovery time to control the cumulative fatigue of trunk muscles in industry with repetitive lifting and lowering task.

• 대한인간공학회지
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• 제27권2호
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• pp.1-7
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• 2008

This study quantified 7 trunk muscles' physiological cross-sectional areas (PCSAs) and developed prediction equations for the physiological cross-sectional area as a function of anthropometic variables for Korean people. Nine females and nine males were participated in the magnetic resonance imaging (MRI) scans approximately from S1 through T8. Muscle fiber angle corrected cross-sectional areas (anatomical cross sectional areas: ACSAs) were recorded at each vertebral level and maximum value of ACSAs were determined as physiological cross sectional area (PCSA). There was a significant gender difference in PCSAs of all muscles (p<0.05). Stepwise linear regression techniques using anthropometric measures (e.g., height, weight, trunk depths and widths) as independent variables were conducted to develop prediction equations for the PCSA for each muscle. For males, six muscles' significant prediction equations (p<0.05) were developed except quadratus lumborum. For females, three prediction equations were developed for psoas, quadratus lumborum, and erector spinae muscles (p<0.05).

• 한국운동역학회지
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• 제12권1호
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• pp.125-133
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• 2002

The purpose of this study was to develop a method for estimating 3-D coordinates of lower trunk muscles using orientation angles during a motion. Traditional 3-D motion analysis system with DLT technique was used to track down the locations of eight reference markers which were attached on the back of the subject. In order to estimate the orientations of individual lumbar vertebrae and musculoskeletal parameters of the lower trunk muscle, the rotation matrix of the middle trunk reference frame relative to the lower trunk reference frame was determined and the angular locations of individual lumbar vertebrae were estimated by partitioning the orientation angles (Cardan angles) that represent the relative angles between the rotations of the middle and lower trunks. When the orientation angles of individual intervertebral joints were known at a given instant, the instantaneous coordinates of the origin and insertion for all selected muscles relative to the L5 local reference frame were obtained by applying the transformation matrix to the original coordinates which were relative to a local reference frame (S1, L4, L3, L2, or L1) in a rotation sequence about the Z-, X- and Y-axes. The multiplication of transformation matrices was performed to estimate the geometry and kinematics of all selected muscles. The time histories of the 3-D coordinates of the origin and insertion of all selected muscles relative to the center of the L4-L5 motion segment were determined for each trial.

• 한국운동역학회지
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• 제22권3호
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• pp.341-348
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• 2012

The purpose of this study was to compare the muscle activities of the thoracic extensor(TE) and lumbar extensor(LE) during trunk lift (TL) exercise according to exercise position. Seventeen healthy subjects with no medial history of back pain were recruited for this study. Subjects performed the TL exercise in prone, quadruped and heel-sitting positions. The activities of the TE and LE were measured using surface electromyography during TL exercise in each exercise position. A one-way repeated-measures analysis of variance (ANOVA) was used to compare the normalized muscle activities of the TE and LE and the TE/LE ratio. The results showed that there was not significant effect of exercise position on the muscle activities of TE(p>.05). However, there was significant effect of exercise position on the muscle activities of LE and the TE/LE ratio(p>.05). Post hoc pair-wise comparisons with Bonferroni correction showed that both muscle activities of LE and TE/LE ratio in prone position were significantly different in those in heel-sitting and quadruped positions, during TL exercise, respectively. The TE/LE ratio was the greatest for TL exercise in heel-sitting position. Therefore, for selective activation of the TE muscle, we recommend performing the TL exercise in heel-sitting or quadruped position.