PNF and Movement, 2019; 17(1): 137-144 https://doi.org/10.21598/jkpnfa.2019.17.1.137 Print ISSN: 2508-6227 Online ISSN: 2508-6472 Original Article Open Access 경사로보행시복부드로잉 - 인기법이몸통및다리의근활성도에미치는영향 이수경 1) 동의대학교물리치료학과 The Effects of Abdominal Drawing-in on Muscle Activity in the Trunk and Legs during Ramp Walking Su-Kyoung Lee Department of Physical Therapy, College of Nersing and Healthcare Sciences, Dong-Eui University Received: March 4, 2019 / Revised: March 25, 2019 / Accepted: March 25, 2019 c 2019 Journal of Korea Proprioceptive Neuromuscular Facilitation Association 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. Abstract Purpose: This study examined the effects of the abdominal drawing-in maneuver (ADIM) on muscle activity in the trunk and legs while subjects walk on a ramp. Methods: The subjects were healthy adult males (n=15) and females (n=8) in their twenties. The subjects were asked to maintain the ADIM contraction for 15 minutes using a pressure biofeedback unit. Their muscle activity was then measured while ascending or descending the ramp with or without the ADIM contraction maintained. Activity in the sternocleidomastoid, splenius capitis, rectus abdominis, external oblique abdominal, transversus abdominis, erector spinae, vastus medialis, and vastus lateralis muscles was measured using surface electromyography (TM DTS, Noraxon, USA). A paired t-test was conducted using SPSS 18.0 (IBM) for statistical data processing. Results: Maintaining the ADIM contraction during ascension led to a significant increase (p<0.05) in muscle activity for the rectus abdominis, transversus abdominis, vastus medialis, and vastus lateralis, but a significant decrease (p<0.05) in muscle activity for the erector spinae, when compared to the same activity without the ADIM maintained. Furthermore, maintaining the ADIM contraction during descent led to a significant increase (p<0.05) in muscle activity for the rectus abdominis, external abdominal oblique, transversus abdominis, vastus medialis, and vastus lateralis, but a significant decrease (p<0.05) in muscle activity for the erector spinae, when compared to the same activity without the ADIM maintained. Conclusion: As a result of this study, it maintains the ADIM and reduces lumbar muscle activity at the waist and increases muscle activity in the legs when walking on a ramp. Therefore, maintaining the ADIM contraction during ramp walking is recommended as training to improve the function of patients muscular skeleton. Key Words: Ramp, Pressure biofeedback unit, Abdominal drawing-in maneuver, Muscle activity Corresponding Author : Su-Kyoung Lee (ptlsk@deu.ac.kr)
138 PNF and Movement Vol. 17, No. 1 Ⅰ. 서론복부중심근육 (Core muscle) 은운동시근골격구조를적절하게유지시켜주고, 자세조절에관여하기때문에코르셋근육 (Corset muscle) 이라고도불린다 (Kinser & Colby, 2010). 대표적으로배가로근 (transverse abdominis), 배빗근 (obilique abdominis), 척추옆근육 (paraspinalis), 볼기근 (gluteus), 뭇갈래근 (multifidus), 골반바닥근 (pelvic floor) 과엉덩관절주변근육들이복부중심근육을이루고있다 (Verhryden et al., 2006). 이러한복부중심근육의불안정성은척추만곡의변형을일으켜거북목 (turtle neck), 굽은등 (sway back), 척추의과도한앞굽음증 (lordosis), 과도한뒤굽음증 (kyphosis), 또는심한옆굽음증 (scoliosis) 을유발하게된다. 또한, 허리뼈에대한과도한부하증가, 골반의변형, 다리의정렬이상등의결과를가져올수도있다 (Kendall et al., 2005). 따라서정상적인복부중심근육은외부환경이변화할때, 신체의상태를일정하게유지하거나조절하는능력인몸통안정성 (trunk stability) 에매우중요한역할을하며 (McNeil, 2010; Zazulak et al., 2008), 이는몸통의균형과보행에큰영향을미친다 (Verhryden et al., 2006). 보행은일상생활동작에서매우중요하고기초적인동작으로, 기본적인운동기능과몸통의이동이동시에이루어지는활동이며 (Hubble et al., 2014), 동시에신체를유지하거나조절하기때문에복근의역할이강조되고있다 (McNeil, 2010; Zazulak et al., 2008). 또한, 보행은일정한방향으로필요한속도를유지하며신체를단계적으로움직이는고도로협응된교대적인운동이며보행과정에서다리는기본적으로체중부하를담당하고안정성과균형을유지하고신체를전방으로추진시키며이동에필요한기본적운동을제공한다 (Galley & Foster, 1987). 특히경사로보행은보행훈련시기본적인요소가되고 (Well, 1981), 계단을대신할수있는수직이동의수단이며, 특히계단을이용하기어려운장애인이나노인, 임산부들을위한필수적인시설이기때문에 (Ryu, 1995) 경사로보행또한 인간에게있어서일상생활을살아가는데매우필수적이다 (Yoon, 1998). 경사로보행에관한선행연구를살펴보면경사로를오르는동안큰볼기근 (gluteus maximus), 안쪽넓은근 (vastus medialis), 뒤넙다리근 (hamstring) 등대부분의다리근육의활성과발현시간이증가하였으며 (Han, 2005), Ounpuu (1990) 는경사로를내려오는동안무릎굽힘근과폄근의수축력이증가됨을보고하였다. 따라서경사로를보행할때평지를보행할때보다근활성도가증가하며, 그에따른역학적노력이더많이필요함을알수있다. 따라서경사로보행에대한체계적인이해는다리의기능을분석하고, 다리기능에영향을미치는여러질환의역학적병인을연구하는데필수적임을확인할수있다 (Well, 1981). 이처럼경사로보행훈련이효과적이라는연구결과가있지만이를응용한연구와더효과적으로훈련을하는방법에관한연구는부족한실정이다. 따라서본연구에서는더효과적인경사로보행훈련을위해서복부드로잉-인기법적용의유무가몸통및다리의근활성도에미치는영향에대해알아보고자한다. 본연구의가설은복부드로잉- 인기법을유지한상태로경사로오르기가유지하지않은상태보다복부근육과다리근육의활성도가증가되고척추세움근은더감소될것이다라고설정하였다. Ⅱ. 연구방법 1. 연구대상본연구는부산광역시 D 대학교에재학중인건강한성인남자 15명, 여자 8명을대상으로하였으며, 본연구의내용및목적에대한설명을듣고, 실험에참여의사를밝힌사람들을대상으로연구를진행하였다. 본연구의대상자선정은근육뼈대계질환으로전문의의진단을받지아니한자, 정상적인보행이가능한자, 배와다리의근력약화가없는자, 신경학적질환이없는자로선정하였다.
경사로 보행 시 복부 드로잉-인 기법이 몸통 및 다리의 근활성도에 미치는 영향 139 2014). 대상자는 압력 생체피드백 장치에 연결되어 있 2. 측정 도구 는 압력계를 40 Hg인 상태에서 10 Hg를 증가시킨 1) 표면 근전도 후 그 상태를 유지하도록 훈련하였고, 이때 대상자는 호기할 때처럼 복부가 약간 들어가도록 배꼽을 상방 본 연구에서는 복부 드로잉-인 기법이 경사로 오르 기와 내려오기 시 근활성도에 미치는 영향을 측정하 과 후방(허리방향)으로 당긴 채로 15분간 실시하였다 (Kim, 2014; Yun, 2013)(Fig. 3). 기 위해서 표면 근전도(TM DTS, Noraxon, USA)를 사 용하였다. 전극을 부착하기 전에 부착부위의 각질을 제거한 뒤, 표면이 부드러운 사포로 약 3회 문지른 후 알코올로 닦아서 피부의 저항을 줄여주었다. 전극 은 몸의 오른쪽 부위 중 최대 수축한 근육의 근복 (muscle belly)에 양극전극을 부착하였고, 2cm 떨어진 부위에 음극전극을 근섬유결의 방향과 평행하게 부착 하였다. 부착부위는 목빗근(sternocleidomastoid, SCM), 머리널판근(splenius capitis), 배곧은근(rectus Abdominal), 배바깥빗근(external oblique,eo), 배가로 근(transverse abdominal), 척추세움근(elector Spinae), 안쪽넓은근(vastus medialis), 가쪽넓은근(vastus lateralis)에 부착하였다(Cram et al., 1998)(Fig. 1). Fig. 2. EMG attachment Fig. 3. Abdominal drawingsite. in maneuver. 3) 모의 경사로 설계 경사로는 높이 45cm, 폭이 100cm, 길이가 360cm인 기울기가 1 : 8인 경사로를 제작하였다(Fig. 4). Fig. 4. Ramp design. Fig. 1. EMG attachment site. 3. 연구 방법 2) 압력 생체 피드백 장치 1) 실험 전 본 연구에서는 압력 생체 피드백 장치(Fig. 2)를 통 해 복부 드로잉-인 기법을 실시하였다. 대상자는 안정 대상자는 연구 방법을 숙지하기 위해 복부 드로잉- 적인 지지면 위에서 무릎관절은 90 굽히고 누운 자세 인 기법을 15분간 실시한 뒤 3분간 휴식 후 복부 드로 를 취한 상태에서 장치를 대상자의 허리뼈 5번 아래에 잉-인 기법을 유지한 상태와 유지하지 않은 상태로 위치시켜서 운동을 실시하였다(Kim, 2008; Kim, 경사로 오르기와 내려오기를 각 1회씩 실시하였다.
140 PNF and Movement Vol. 17, No. 1 2) 실험 Ⅲ. 연구결과 본실험은무작위배정비교 (randomized controlled trial) 를통해 (Ahn, 2018) 복부드로잉- 인기법을유지한상태와유지하지않은상태에대한순서를정하였고그순서절차에따라연구대상자는경사로오르기와내려오기시에대한근활성도를측정하였으며, 대상작용을방지하기위해각순서절차마다 3회반복측정후 3분간휴식을취하였다. 4. 자료분석 1) 근전도신호처리분석근활성도를측정하기위하여 8개채널의표면근전도를사용하였으며, 데이터는경사로보행시첫걸음과마지막으로내딛은걸음을제외한중간값을사용하였다. 필터링 (Band pass filter 20-450Hz, Notch filter 60Hz) 과기타신호를처리 (rectification, smoothing) 하였다. 또한수집된근전도신호를 RMS (root mean square) 로처리하였으며특정동작을기준값으로하여사용하는 %RVC (reference voluntary contraction) 값을이용해정규화 (normalization) 하였다. 2) 통계분석 1. 연구대상자의일반적인특성본연구는정상성인남녀 23명을대상으로실험을실시하였으며, 평균나이는 22.57±2.02세이며, 평균키 169.57±9.77cm, 평균몸무게는 63.57±13.26Kg 이었다 (Table 1). Table 1. General characteristics of subjects (n=23) Characteristics Sex (geneder) Male (15)/Female (8) Age (yerars) 22.57±2.02 Height (cm) 169.57±9.77 Weight (kg) 63.57±13.26 2. 경사로오르기시복부드로잉-인기법유무에따른근활성도비교근전도를이용하여오른쪽몸통및다리의근활성도를측정한결과경사로오르기시배곧은근, 배가로근, 안쪽넓은근, 가쪽넓은근은복부드로잉- 인기법을적용하기전보다적용후에유의하게증가하였고 (p<0.05), 척추세움근은유의하게감소하였다 (p<0.05)(table 2). 자료분석은 SPSS version 18.0을이용하여통계처리를실시하였으며, 복부드로잉-인기법으로경사로보행시몸통및하지근육의활성화를알아보기위하여각각의대응표본t-test (paired t test) 을사용하였다. 이때통계학적유의수준을검증하기위한유의수준은 0.05로설정하였다. 3. 경사로내려오기시복부드로잉-인기법유무에따른근활성도비교근전도를이용하여오른쪽몸통및다리의근활성도를측정한결과경사로내려오기시배곧은근, 배바깥빗근, 배가로근, 안쪽넓은근, 가쪽넓은근은복부드로잉-인기법을적용하기전보다적용후에유의하게증가하였고 (p<0.05), 척추세움근은유의하게감소하였다 (p<0.05)(table 3).
경사로보행시복부드로잉 - 인기법이몸통및다리의근활성도에미치는영향 141 Table 2. Comparison of muscle activity according to abdominal drawing-in maneuver with ascending ramp (n=23, unit: %RVC) Muscle Pre Post t p SCM 651.17±127.25 814.10±181.65 1.48 0.15 SC 764.07±140.52 614.23±87.97-1.70 0.10 ABD 835.04±151.82 1219.73±248.47 2.70 0.01* EOB 1180.69±285.94 1553.93.±395.56 1.86 0.08 TRA 1212.65±208.43 3049.15±874.06 2.39 0.03* ES 2532.38±541.27 1250.11±188.79-2.79 0.01* VMO 4552.05±1267.24 8818.56±2309.85 3.47 0.00* VLO 4782.78±1265.16 7122.00±1807.74 2.58 0.02* SCM: sternocleidomastoid, SC: splenius capitis, ABD: rectus abdominis, EOB: external abdominal oblique, TRA: transverse abdominis, ES: erector spinae, VMO: vastus medialis, VLO: vastus lateralis *p<0.05, Mean±SE Table 3. Comparison of muscle activity according to abdominal drawing-in maneuver with descending ramp (n=23, unit: %RVC) Muscle Pre Post t p SCM 620.90±104.29 821.86±183.91-1.18 0.25 SC 637.04±93.33 697.23±99.73-0.63 0.54 ABD 854.17±165.34 1249.69±233.01-2.90 0.01* EOB 952.08.±212.47 1667.35±457.49-2.65 0.01* TRA 980.70±163.11 3280.93±1175.21-2.07 0.05* ES 2205.83±389.43 1311.61±252.51 2.53 0.02* VMO 5519.45±1218.96 10116.82±2605.54-2.76 0.01* VLO 4430.06±1119.22 7080.15±1968.61-2.53 0.02* SCM: sternocleidomastoid, SC: splenius capitis, ABD: rectus abdominis, EOB: external abdominal oblique, TRA: transverse abdominis, ES: erector spinae, VMO: vastus medialis, VLO: vastus lateralis *p<0.05, Mean±SE Ⅳ. 고찰본연구에서는경사로오르기와내려오기시복부드로잉 -인기법의유무에따라몸통및다리근활성도차이를알아보고자한다. 본연구결과경사로오르기시복부드로잉-인기법을유지한상태가유지하지않은상태에비하여배곧은근, 배가로근의근활성도가유의하게증가하였고경사로내려오기시에는배가로근, 배곧은근, 배바깥빗근의근활성도가유의하게증가하였다. 복부드로잉- 인기법수행시복부근육이많이활성화되는데특히배가로근, 배바깥빗근, 배곧은근등이많이활성화되며 (O Sullivan et al., 2013), 이러한근육들은기능적활동시에내부복압을증가시켜체간을안정화시키는역할을한다 (Standaert et al., 2008). 복부드로잉- 인기법은복부근육의두께를두꺼워지게하여근활성도를증가시키며 (chon, 2010), 또한, 수직보행시에복부드로잉- 인기법을적용하였을때도복부근육의활성도는유의하게증가한다고하였다 (Lee et al., 2011). 본연구에서도선행논문에서의결과와일치
142 PNF and Movement Vol. 17, No. 1 하게수직보행중하나인경사로보행시복부드로잉- 인기법을적용하였을때복부근육의활성도가유의하게증가하였다는결과가나왔다. 반면에척추세움근의근활성도는복부드로잉-인기법을적용한상태에서경사로오르기와내려오기를했을시유의하게감소하였다. 복부드로잉 -인기법은체간을안정화시켜주어복부근육들의근활성도를증가시켜주며 (Hong, 2014), 복부근육활성시척추에작용하는압력과전단력을줄여준다 (Kendal, 2005). 그러므로복부드로잉- 인기법을유지하였을때척추세움근의근활성도가감소한다 (Kinser & Colby, 2010). 또다른선행논문에서는복부드로잉- 인기법이복강내압을증가시켜척추가받는힘을낮춰주어척추사이에가해지는내부압력을감소시키기때문에척추세움근의근활성도가감소한다고보고하였다 (Park & Kim, 2009; Smith et al., 1996; Udo & Yoshinaga, 1997). 본연구에서도복부드로잉 -인기법을적용하였을때척추세움근의활성도가유의하게감소하여선행논문들과일치한결과가나왔다. 복부드로잉- 인기법시복부근육들의동시수축을유도하여과도한허리의전만이나골반의전방경사를줄여주고, 척추사이내부압력을감소시켜효과적인허리안정화 (lumbar stabilization) 에기여한다 (Kinser & Colby, 2010). 결과적으로복부드로잉-인기법적용시복부내압을증가시킴과동시에체간의안정성을증진시켜척추세움근의근활성도가감소된다고판단된다. 보행시사용되는다리근육중안쪽넓은근과가쪽넓은근은체중부하구조로서신체를앞으로이동시키며이동에필요한운동을제공하는역할을한다 (Yun et al., 1999). 경사로보행시안쪽넓은근, 가쪽넓은근의근활성도가증가하며 (Han, 2017), 다리근육의근활성도가증가할시체간의안정성이증진된다 (Ahn, 2009). 또다른선행연구에서도복부드로잉- 인기법시다리근활성도가높게나타났다고보고하였다 (Lee et al., 2016). 본연구에서도복부드로잉 -인기법을적용하였을때가쪽넓은근, 안쪽넓은근의활성도가유의하게증가하였다. 복부근육의강화는다리의근수축을방 산시켜다리의근력을증가시키며 (Hwang & Kim, 2011), 따라서복부드로잉-인기법을유지하였을때몸통의안정성이증진되면서다리근육의근활성도증가된다는본연구의결과와일치한다. 본연구에서도경사로보행시복부드로잉-인기법을적용하기전보다후에복부, 다리근육에서근활성도는높게측정되었고척추세움근에서근활성도가낮게측정되었다. 따라서복부드로잉-인기법을유지한상태로경사로보행을하게되면복부근육과다리근육의근활성도가증가하고, 척추세움근의근활성도가감소하여결론적으로체간의안정성을증가시킨다. 이러한결과를토대로복부드로잉-인기법을유지하고경사로오르기과제를수행하는방법이근육뼈대계환자들의몸통근육기능을회복하는데기여를할수있을것으로사료된다. 그러나본연구는몇가지제한점이있는데제한점으로는근육뼈대계환자들을대상으로하지않고 20대건강한대학생을대상으로하였으며, 복부드로잉- 인기법유무에따른경사로오르기시의즉각적인효과만을측정하여일시적인변화를기록하였다. 따라서향후연구에서는근육뼈대계환자군을대상으로몇주간의중재를통하여비교적정확한방법으로다양한연구들이이루어져야할것이다. Ⅴ. 결론본연구는부산 D대학에재학중인남자 15명, 여자8 명을대상으로근전도를이용하여경사로에서보행시복부드로잉-인기법적용의유무가근활성도에미치는영향에대해알아보고자하였다. 복부드로잉- 인기법을적용하고경사로오르기시에배곧은근, 배가로근, 안쪽넓은근, 가쪽넓은근의근활성도가유의하게증가하였고척추세움근의근활성도는유의하게감소하였다. 또한, 복부드로잉- 인기법을적용하고경사로내려오기시에배곧은근, 배가로근, 배바깥빗근, 안쪽넓은근, 가쪽넓은근의근활성도가유의하게증가하였고척추세움근의근활성도는유의하게감소
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