J Korean Soc Phys Med, 2020; 15(2): 49-56 https://doi.org/10.13066/kspm.2020.15.2.49 Online ISSN: 2287-7215 Print ISSN: 1975-311X Research Article Open Access 복부드로잉 - 인기법이평지보행시몸통과다리의근활성도에미치는효과 안수홍 이수경 1 조현대 2 동의대학교보건의과학과물리치료전공, 1 동의대학교물리치료학과, 2 곤지암중학교 Effects of Abdominal Drawing-in Maneuver on Muscle Activity of the Trunk and Legs during Flat Walking Su-Hong Ahn, PT, MS Su-Kyoung Lee, PT, PhD 1 Hyun-Dai Jo, PhD 2 Department of Biomedical Health Science, Graduate School, Dong-Eui University 1 Department of Physical Therapy, College of Nursing, Healthcare Sciences, Dong-Eui University 2 Major of Physical Education, Gonjiam Middle School Received: November 16, 2019 / Revised: November 28, 2019 / Accepted: January 3, 2020 c 2020 J Korean Soc Phys Med Abstract 1) PURPOSE: This study examined the difference in muscle activity of the trunk and legs during flat walking with or without an abdominal drawing-in maneuver. METHODS: This study was conducted on 15 healthy males and eight females who were attending D University in Busan. This experiment was conducted after 15 minutes of abdominal drawing-in training using a pressure biofeedback unit before the experiment, and the difference in the muscle activity of the trunk and legs during flat walking with or without an abdominal drawing-in technique was investigated. Surface electromyography was used, and the electrode attachment site was the right sternocleidomastoid muscle, Corresponding Author : Su-Kyoung Lee ptlsk@deu.ac.kr, https://orcid.org/0000-0002-4916-2188 This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. splenius capitis muscle, rectus abdominis muscle, external abdominal oblique muscle, transverse abdominis muscle, erector spinae muscle, vastus medialis muscle, and vastus lateralis muscle (TM DTS, Noraxon, USA). The data were analyzed statistically using a paired t-test on SPSS version 18.0 (IBM). RESULTS: The muscle activity of the rectus abdominis muscle, external abdominal oblique muscle, transverse abdominis muscle, vastus medialis muscle were increased significantly and maintained more than walking without maintaining an abdominal drawing-in maneuver (p <.05). Moreover, muscle activity of the erector spinae muscle was decreased significantly and maintained more than walking without maintaining an abdominal drawing-in maneuver (p <.05). CONCLUSION: Maintaining an abdominal drawing-in maneuver during flat walking is more effective during walking training. Key Words: Abdominal drawing-in maneuver, Biofeedback unit, Flat walking, Muscle activity
50 J Korean Soc Phys Med Vol. 15, No. 2 Ⅰ. 서론안정화운동은신체의움직임조절능력을회복시켜주며, 신체정렬유지및허리통증의예방및치료에큰역할을하고 [1] 고유수용성감각조절능력과균형및지구력을향상시켜주는역할을한다 [2]. 또한, 몸통근육의수축을조절하여분절의불안정성과미세손상의축적을줄여주는역할을하며, 신체의자세변화와움직임동안척추와골반의안정성을증가시킨다 [3-5]. 안정화를담당하는근육은크게광역근육계와국소근육계로나뉘며, 광역근육계는배곧은근, 배바깥빗근등으로구성되어몸통의회전력을발생시키고전반적인몸통의안정성에기여한다. 국소근육계는배가로근, 배속빗근등으로구성되어있으며, 척추의분절을안정화시켜움직임시허리뼈에직접적인안정성을제공하는역할을한다 [6,7]. 안정화운동중하나인복부드로잉- 인기법 (Abdominal drawing-in maneuver) 은배근육들을기능적으로자극하여 [8] 배벽을안쪽으로당겨배근육의동시수축을유도하여배안쪽의압력을증가시키고근육의동시수축을통해허리안정화 (Lumbar stabilization) 를효과적으로수행하게하며동시에과도한허리의전만이나골반의전방경사를감소시켜준다 [9]. 또한, 골반을중력중심선에가까운위치로회복시키며허리의중립자세를유지시켜허리에가해지는스트레스를줄여준다 [10]. 즉, 복부근육의조절은몸통안정화및자세조절을통해정상적인자세를유지할수있도록하는매우중요한역할을한다 [11]. 정상적인자세는척추가정상적인곡선을이루고, 인체분절들이수직정렬내에있으며, 체중분산이각관절들의밑면에골고루분산되어근육과관절에최소한의압력을받는상태라고하였다 [12,13]. 그러나현대인들은뼈대가무너지는장시간오래앉아있는자세, 비만, 운동부족등으로인하여자세와관련된문제점들이많다 [14]. 이처럼자세정렬에변화가있으면근육뼈대계에문제가발생할수있고정상적인움직임이나운동에도제한이올수있으며, 더나아가인간의이동수단인보행에도영향을미친다고하였다 [12]. 보행이란두다리를반복적으로이용하여한장소에서또다른장소로이동하는것을의미하며 [15], 인간이 일상생활및독립적인생활을영위하는데있어서가장기본이되고중요한역할을하며 [16], 100여개이상의팔다리의뼈대가모든관절에서상호협력하여복잡한신체활동을가능하게하며 [17], 동시에신경과근육등이사용되어몸을앞으로계속움직이게하는반복적인동작이라고하였다 [18]. 즉, 보행은머리, 몸통, 팔다리가상호연관성이있으며, 체중부하를통해신체를앞으로추진시키는동안안정성과균형을유지하여이동에필요한기본적인운동을제공하며 [19], 복부근육들을활성화시켜몸통근육들을조절하는몸통안정화운동과도관련이있다고하였다 [20,21]. 이처럼보행과몸통안정화운동은서로상관관계가있기때문에다양한방법을통해신체에운동효과를극대화시킬수있는기초적인자료를제시할필요가있다. 따라서본연구에서는몸통안정화운동중하나인복부드로잉-인기법과보행을동시에적용하여몸통및다리의근활성도에미치는영향에대해알아보고자한다. Ⅱ. 연구방법 1. 연구대상자본연구는부산에소재한 D대학교에재학중인건강한 20대성인남자 15명여자 8명을대상으로실시하였다. 본연구를시작하기에앞서연구대상자에게연구의목적과절차에대하여설명하고이를충분히숙지시킨다음실험에참여하도록하였고연구대상자의선정기준은최근 6개월이내에근육뼈대계질환의진단을받지아니한자, 복부와다리의근력약화가없는자, 정상적인보행이가능한자로선정하였다. 2. 측정도구 1) 표면근전도평지보행시복부드로잉- 인기법유무에따른몸통및다리의근활성도를알아보기위해표면근전도 (Myosystem TM DTS, Noraxon Inc., USA) 를사용하여배곧은근 (Rectus Abdominal, RTA), 배바깥빗근 (External oblique,eo), 배가로근 (Transverse abdominal, TRA), 척
복부드로잉 - 인기법이평지보행시몸통과다리의근활성도에미치는효과 51 추세움근 (Elector Spinae, ES), 안쪽넓은근 (Vastus medialis oblique, VMO), 가쪽넓은근 (Vastus lateralis oblique, VLO) 을측정하였다. 전극을부착하기전피부에대한전기저항을줄이기위해알콜솜을이용하여각질을제거한뒤 Ag/Agcl 재질의일회용표면전극을사용하였다. 전극은 6채널을사용하였고부착부위는오른쪽이였으며다음과같다. 배곧은근은칼돌기외측을따라 3 cm 지점에서아래 5 cm에위치, 배바깥빗근은두덩뼈결절과 8번째갈비뼈를이은가상선에서 8번째갈비뼈의아래 2 cm에위치, 배가로근은엉덩뼈능선의위에서부터안쪽방향으로 2 cm 아래로떨어진위치, 척추세움근은 1번허리뼈의가시돌기에서가쪽으로 2 cm 떨어진힘살부위에척추와평행하게 2 cm 떨어진위치, 안쪽넓은근은위앞엉덩뼈가시에서무릎의안쪽 20% 사이의거리에위치, 가쪽넓은근은위앞엉덩뼈가시에서무릎의바깥쪽 25% 사이의거리에부착하였다 [22]. 근활성도측정은 10 m의구간을각대상자가평소에걷는속도로복부드로잉- 인기법을적용하고보행하는것과복부드로잉 -인기법을적용하지않고보행시처음과마지막데이터를제외한 3보의데이터를결과값으로사용하였으며, 총 3회측정하여평균화하였다 (Fig. 1)[23,24]. 근전도주파수는 2000 Hz로샘플링하여기록하였고대역필터 (Band pass filter) 는 20-450 Hz 주파수대역을사용하여노이즈제거후, 평균제곱근 (Root mean square, RMS) 의값을도출하였다. 기타신호는 Rectification과 Smoothing으로제거하였다. 2) 압력생체피드백장치본연구실험전허리의안정성을높이기위해운동의 질과정확도의피드백을제공해주는압력생체피드백장치 (Stabilizer, Chattanooga Group Inc, USA) 를통해복부드로잉-인기법을교육하였다. 대상자는바로누운자세에서무릎관절은 90 굽히고압력생체피드백장치를대상자의허리뼈부위에위치시켰다. 대상자는압력생체피드백장치에연결되어있는압력계를 40 mmhg인상태에서 10 mmhg 를증가시킨 50 mmhg 상태를눈으로확인시켜유지하도록교육하였고, 이때연구대상자에게척추와갈비뼈그리고골반을고정시킨상태에서복부가허리방향으로들어가도록배꼽을위쪽과밑으로천천히당기면서유지하라고지시하였다 [25]. 복부드로잉- 인기법을하는동안정상적인호흡을위해서는적당한강도로배꼽을넣어야하기때문에소변을참듯이아래배에천천히힘을주세요라는구두명령을지시하였다 (Fig. 2)[26]. 복부드로잉-인기법의교육은 10초를유지하였고 1회실시후 5초동안휴식을취하였다. 총 10회씩반복하여 5세트실시하였으며 [27], 복부드로잉-인기법유무에따른평지보행또한 3분의연습을통하여충분히숙지한뒤본실험을실시하였다. 보행구간은 10 m로설정하였고보행속도는연구의결과에영향을미치지않도록각대상자가평소에걷는속도로설정하였다 [24,25]. 3. 실험절차대상자에게실험절차와방법에대해설명을하였고, 실험전복부드로잉-인기법교육을먼저실시하여충분히학습한뒤실험자의지시에따라평지보행시복부드로잉- 인기법유무에따른근활성도차이를알 Fig. 1. EMG attachment site. Fig. 2. Abdominal drawing-in maneuver.
52 J Korean Soc Phys Med Vol. 15, No. 2 아보기위해근전도신호량을측정하였다. 실험순서는각대상자에게무작위배정을통해복부드로잉-인기법을유지한상태와유지하지않은상태의순서를정하였다. 순서의결과는복부드로잉 -인기법을먼저유지하고실험을실시한대상자가 12명이였으며, 복부드로잉-인기법을유지하지않고실험을먼저실시한대상자가 11명으로무작위배정을통해나타난실험순서의비율은비슷하였다. 측정방법은복부드로잉-인기법유무에따라서각대상자가평소에걷는속도로 10 m 평지구간보행시근활성도를측정하여비교하였다. 모든근전도자료는처음과마지막데이터를제외한 3보의데이터를결과값으로사용하였고 3회반복측정하였으며, 3번측정된결과값들을평균화였다. 정량화를위해평지보행전에특정동작인해부학적자세를 5초간유지하여표준근육수축값을측정하였고, 근전도신호를표준화하는 %RVC (Reference voluntary contraction) 를통해근전도신호를표준화하였다. 4. 자료분석본연구에서수집된결과값은평균 ± 표준오차 (Mean ± SE) 로기술하였고 SPSS version 18.0을이용하여통계처리를실시하였으며, 연구대상자의일반적특성은기술통계를사용하였다. 또한, 복부드로잉-인기법유무에따른평지보행시몸통및다리근육의근활성도차이를알아보기위하여비모수통계검정인윌콕슨부호순위검정 (Wilcoxon signed rank test) 을사용하여분석하였다. 이때통계학적유의수준은.05로설정하였다. Ⅲ. 연구결과 1. 일반적특성본연구는남자 15명여자 8명으로총 23명으로실험을진행하였고, 대상자의평균나이는 22.57 ± 2.02세, 평균신장은 169.57 ± 9.77 cm, 평균체중은 63.57 ± 13.26 kg이었다 (Table 1). 2. 평지보행시복부드로잉-인기법유무에따른근활성도비교평지보행시근전도를이용한오른쪽몸통및다리의근활성도를측정한결과배곧은근, 배바깥빗근, 배가로근, 안쪽넓은근은복부드로잉-인기법을유지하지않고보행하는것보다유지하고보행하는것이유의하게증가하였고 (p <.05), 척추세움근은유의하게감소하였다 (p <.05)(Table 2). Ⅳ. 고찰본연구는근전도기기를통하여복부드로잉-인기 Table 1. General Characteristics of the Subjects Variables Values Sex (Male / Female) 15 / 8 Age (year) 22.57 ± 2.02 Height (cm) 169.57 ± 9.77 Weight (kg) 63.57 ± 13.26 Mmean (± Standard Deviation) Table 2. Comparison of Muscle Activity with Abdominal Drawing-in During Flat Walking (unit : % RVC) Muscle Pre Post Z P RTA 2403.43 ± 354.40 2992.05 ± 549.86-2.346.019* EO 2823.20 ± 372.25 4044.87 ± 816.45-2.589.010* TRA 3654.55 ± 496.54 6505.63 ± 894.22-3.806.000* ES 5533.96 ± 748.55 3611.94 ± 456.29-2.589.010* VMO 12031.18 ± 1999.35 14047.14 ± 2386.83-2.346.019* VLO 11440.51 ± 2214.20 11576.41 ± 2226.37-3.330.741 Mean (± Standard Error), *P.05 RTA: Rectus abdominis, EO: External abdominal oblique, TRA: Transverse abdominis, ES: Erector spinae, VM: Vastus medialis, VL: Vastus lateralis
복부드로잉 - 인기법이평지보행시몸통과다리의근활성도에미치는효과 53 법의유무에따라평지보행시몸통및다리의근활성도의차이를알아본결과복부드로잉-인기법을유지한보행이유지하지않은보행에비하여배곧은근, 배바깥비근, 배가로근의근활성도가유의하게증가하였다. 몸통안정화운동은다양한환자들에게적용가능하며, 허리통증의감소와보행능력과유연성그리고근력및균형능력을향상시켜삶의질을개선시켜준다 [28]. 몸통안정화운동중하나인복부드로잉-인기법은복부근육을활성화시키는데특히배가로근, 배곧은근, 배바깥빗근과같은심부근육을많이활성화시키며 [29], 복부의수의적움직임과운동을조절하고몸통의안정화에기여한다 [25]. Lee [30] 는경사로보행시복부드로잉기법을유지하는것이유지하지않았을때보다복부의근활성도가유의하게증가한다하였고, 계단보행또한복부드로잉- 인기법수행이수행하지않았을때에비하여몸통의안정성이증가하여척추의동적안정성에기여하는복부의근활성도가유의하게증가한다고하였다 [31]. 본연구에서도경사로와계단과같은수직보행시의선행연구결과처럼수평보행에서도복부드로잉- 인기법을유지하는것이복부의근활성도가유의하게증가한다고나왔는데이는기능적활동시내부복압을증진시켜몸통을안정화시키며, 보행시자세조절을통해몸통을안정화시키기위해복부의역할이크게작용하기때문이다 [32,33]. 반면에척추세움근의근활성도는유의하게감소하였는데복부드로잉- 인기법시몸통을안정화시키는복부근육들이활성화되어공동수축을유도해심부의안정성을증가시킨다. 따라서허리의내적안정화에기여하여척추를중립위치에유지하도록신체에적절한반응속도를회복시켜허리에가해지는압력을감소시키며 [34-36], 신경근조절을통하여사전에허리의통증을예방한다 [37,38]. 또한, 복부의벽을허리쪽방향으로당김으로써복부내압을증가및복부근육을수축시켜허리의안정성을증가시키며, 근육의동시수축을통해과도한허리및골반전방경사를줄여준다 [9]. Oh 등 [39] 은복부드로잉-인기법을유지하며엎드린자세에서엉덩관절폄운동시허리폄근의근활성도가유의하게감소한다고하였고, Park 등 [40] 의연구에 서도복부드로잉 -인기법을유지하는것이허리폄돌림증후군이있는환자의허리폄근의근활성도가감소하여허리통증이줄어들었다고하였다. 따라서, 본연구에서복부드로잉인기법으로인해복부의근육들이몸통을안정화시키고허리의전방경사를줄여주어허리의폄근의작용이감소하여척추세움근의활성도가감소하였다고볼수있다. 안쪽넓은근은무릎관절의기능적인움직임과안정성을동시에제공하며 [41], 보행시신체를앞으로이동시키는체중부하구조로서이동에중요한역할을한다 [42]. 본연구에서안쪽넓은근의근활성도는복부드로잉-인기법을유지한상태에서유의하게증가하였는데, 배근육의활성화는골반을안정화시키며, 골반이안정화된상태는몸통에미치는힘들이효율적으로다리로전달이되며 [43], 또한, 배근육의수축을통해몸통을안정화시키고다리의가동성을증진시킨다 [44,45]. 이처럼배근육의자극은방산효과를통해다리를근수축시켜다리의근력을증가시키며 [46], 근육의협력작용을통해증가된다리의근활성도는척추안정화에기여하는배근육들의활성도또한증가시키기때문에본실험의연구결과를뒷받침해준다 [47]. 따라서보행시복부드로잉- 인기법을유지하는것이몸통의심부근육들을활성화시켜몸통을안정화시키고복부근육의동시수축을통해허리의전만을줄여준다. 또한, 골반을안정화시켜몸통에미치는힘들이효율적으로다리에전달되어다리의근육이활성화되기때문에몸통의기능개선및다리의근력강화운동이필요한사람들에게효과적일것이라고판단된다. 더나아가허리의통증이나자세의기능개선에도긍적적인효과가있으므로허리통증이나자세등에문제가있는사람들에게적용하면효과적일것이라고생각된다. 향후허리통증환자나자세등에문제가있는환자를대상으로진행하는다양한연구가필요할것으로사료된다. Ⅴ. 결론본연구는건강한 20대남녀 23명을대상으로평지보행시복부드로잉-인기법유무에따라서몸통및
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