JKPT pissn Vol. 27, No. 4, August 2015 1229-0475 eissn 2287-156X Original Article Effects of Gluteus Medius Strengthening Training Using Pressure Biofeedback Unit for Muscle Function and Balance in Stroke Patients Jeong-Ju Park 1, Hyun-Jeong So 1, Won-Seob Shin 2 1 Department of Physical Therapy, Graduate School of Daejeon University; 2 Department of Physical Therapy, College of Health and Medical Science, Daejeon University, Daejeon, Korea Purpose: The purpose of this study was to examine the impact of gluteus medius (GM) strengthening training using the pressure biofeedback unit for lower extremity muscle function and balance ability in stroke patients. Methods: Twenty-seven stroke patients (14 men, 13 women) volunteered to participate in this study. They were randomly assigned to 3 groups: pressure biofeedback unit GM training, general GM training, and control group. Experimental group 1 performed GM strengthening training using PBU in the sidelying position. Experimental group 2 performed GM strengthening training without PBU in the sidelying position. The training program lasted 4 weeks (20-minute sessions, three times a week). Muscle function was assessed by measuring muscle strength and endurance, and Berg balance scale (BBS), Lateral Reach Test (LRT), and limited of stability (LOS) velocity were measured for evaluation of balance ability. Results: Enhancement of muscle strength and endurance was significantly higher in experimental group 1 than in the other two groups (p< 0.05). In comparison of the balance function, experimental group 1 showed a significantly enhanced ability to balance (p< 0.05). After the intervention, experimental group 1 showed a significant reduction of LOS velocity in the anterior direction and affected direction (p< 0.05). There was no significant difference than the other two groups but a large reduction was observed. Conclusion: These findings suggest that selective gluteus medius strengthening training using the pressure biofeedback unit is effective for lower extremity muscle function and balance ability in stroke patients. Keywords: Pressure biofeedback unit, Gluteus medius, Strength, Endurance, Balance, Stroke 서론하지근력약화는뇌졸중환자에게서나타나는가장흔한증상이다. 1 일반적으로하지의근력약화는마비측하지로의체중지지를방해하고비대칭적인자세와신체불균형을유발하여체중이동능력을감소시킨다. 또한다리의기능적움직임을저하시켜결과적으로는기립과균형및보행에어려움을가져온다. 2,3 골반과척추의안정성을유지시키는요소들은근육간에균형과지구력, 근력에의해좌우되는데엉덩관절벌림근은보행과정에서골반의중요한안정화근육으로하지의병리학적관계에서도중요하게여겨지고있다. 4 특히, 중간볼기근은대표적엉덩관절벌림근으로서, 전체적으로는엉덩관절벌림에작용하고몸쪽부에따라엉덩관절안쪽돌림과바깥 돌림에기여한다. 또보행시몸통옆굽힘의원인이되고하지의안정화유지와보폭을조절하는역할을한다. 중간볼기근과작은볼기근은발디딤기에하지전체를체중지지하기때문에관절안정성에도움을주고, 무게중심을가쪽으로옮길수있도록작용한다. 4,5 이렇게엉덩관절과골반의안정성제공에중요한역할을하는중간볼기근이약화되거나억제되면, 골반의가쪽전위나하강이유발되며허리통증발생및기능적저하를일으켜낙상의위험이높아지게된다. 6 특히뇌졸중환자에게서중간볼기근약화로인한골반의안정성감소와조절능력의저하는이를해결하기위한보상작용을더욱촉진시킨다. 7 이는불필요한에너지를소모하게하고정상보행을학습할기회를방해한다. 8 따라서뇌졸중환자의균형능력및보행향상위해중간볼기근강화가요구되며, 여러선행연구들에서다양한엉덩 Received Jul 23, 2015 Revised Aug 13, 2015 Accepted Aug 16, 2015 Corresponding author Won-Seob Shin E-mail Shinws@dju.kr Copylight 2015 The Korea Society of Physical Therapy This is an Open Access article distribute under the terms of the Creative Commons Attribution Non-commercial License (Http:// creativecommons.org/license/by-nc/3.0.) which permits unrestricted non-commercial use, distribution,and reproduction in any medium, provided the original work is properly cited. www.kptjournal.org 221
JKPT The Journal of Korean Physical Therapy Jeong-Ju Park, et al. 관절벌림근강화훈련을통한균형능력및보행향상에대한사례들이보고되고있다. 9-12 일반적으로허리나엉덩관절에병리를가진사람들이중간볼기근강화를위해옆으로누운자세에서엉덩관절벌림운동을많이실시하는데, 13 이는적절한신경근조절을일으키기위해초기재활프로그램에서사용되는열린사슬운동으로서, 목표화된중간볼기근활성에효과적이라고하였다. 14 하지만, 옆으로누운자세에서엉덩관절벌림을하는경우허리네모근의과도한사용과빠른수축으로골반이가쪽기울임되는보상작용이발생할수있다. 6,15 따라서하지의역동적인움직임동안골반의안정화에관여하는중간볼기근의선택적강화는중요하게여겨지며허리및하지의근골격계재활운동시필요하다. 이때발생되는원치않는움직임의조절은운동치료시중요하게인식되고있다. 건강한성인을대상으로외재적피드백을적용하는것은운동학습을촉진하는데매우유용한방법으로많은연구를통해입증되었고그에따른적용지침이제공되어왔다. 16,17 반면, 뇌졸중환자의재활에있어일부외재적피드백의적용이운동학습을보강한다고제안되어왔지만외재적피드백에관해아직많은부분이연구되지않았고정보가부족한상태이다. 16-18 뇌졸중환자는종종뇌손상으로인하여내재적감각정보를수용하는데어려움이있으며, 관절가동범위나근력, 운동조절능력의감소를보상하기위해비정상적인운동패턴을사용하는특징이있다. 16 외재적피드백제공은수행자가인식하지못하는유용한정보를제공하고, 잘못된움직임을수정하여올바르게이끌어주는역할을하기때문에뇌졸중환자의운동재교육에서보다더중요한역할을할것이다. 16-20 Cynn 등 21 은엉덩관절벌림시피드백에의해대상자가스스로골반가쪽기울임를억제하는내적고정방법을제시하였다. 이는압력바이오피드백기구 (pressure biofeedback unit, PBU) 를엉덩뼈능선과먼쪽부분갈비뼈사이의몸통아래에놓아대상자가압력의변화를통해몸의자세변화를인지하도록하는방식으로, 운동하는동안원치않는동작에따른피드백을추가로제공함으로써주변근육의대상작용을감소시키고중간볼기근의활동을증가시키는원리이다. 선행연구에서살펴본바와같이중간볼기근강화훈련이나외재적피드백제공을통한운동학습의효과들은각각보고되었으나, 중간볼기근강화와외재적피드백운동학습훈련을함께시행하였을때뇌졸중환자의하지근기능및균형능력향상에관한연구는부족한실정이다. 따라서본연구는중간볼기근강화훈련시압력바이오피드백기구를통한외재적피드백제공이뇌졸중환자의근력, 근지구력, 그리고균형능력향상에어떠한영향을미치는지알아보고자하였다. 연구방법 1. 연구대상본연구는대전에소재한 D재활병원에서입원치료를받고있는뇌졸중환자중실험에참여하기로동의한 27명을선정하였으며, 선정기준은뇌졸중으로유병기간이 6개월이상인자, 엉덩관절벌림근력이 Fair 이상인자, 연구자가지시하는내용을이해하고따를수있는한국형간이정신상태판별검사 (MMSE-K) 점수가 24점이상인자로선정하였다. 시각적또는청각적결함이있는자, 골반및양하지에정형외과적질환이있는자, 심각한심혈관계문제가있는자는대상자에서제외하였다. 연구에앞서대상자에게과정및방법에대해설명하였고, 본연구에참여하기로동의한자들만중재에참여하도록하였다. 2. 연구절차선정기준에의해선별된뇌졸중환자 27명을 PBU 중간볼기근강화군, 일반적중간볼기근강화군과대조군으로각각 9명씩무작위배정하였다. 본연구의중재기간은총 4주이다. 연구기간동안모든대상자는군에상관없이일반적인신경계물리치료를 30분씩주 5회실시하였으며 ( 대조군 ), PBU 중간볼기근강화군과일반적중간볼기근강화군는추가적으로중간볼기근강화훈련을 20분씩, 주 3회실시하였다. 사전평가로근력, 근지구력, 균형능력평가를실시하였다. 중재후에사전평가했던항목을재평가하였다. 3. 중재방법중간볼기근강화훈련을위해, 각대상자는치료용매트에비마비측이아래쪽으로오도록옆으로누워마비측몸통과골반, 다리가일직선상에정렬되도록하였다. 비마비측다리는편안함과안정성을위하여골반의움직임이일어나지않는범위에서엉덩관절과무릎관절을굽힘하도록하였다. 마비측다리는골반이뒤돌림되지않는범위내에서무릎을완전히폄한상태로엉덩관절벌림을실시하였다 (Figure 1A, B). 벌림하는다리는환자가최대로움직일수있는범위내에서움직이도록하였고 30도이상넘어가지않도록하였다. 훈련단계는엉덩관절벌림을등척성 (isometric) 운동으로 10분간실시하고, 이어서동심수축과편심수축을포함한등장성 (isotonic) 운동으로 10분간실시하였다. 등척성운동시치료사가환자의엉덩관절벌림중간범위를만들어준상태에서자세를유지하도록하였고, 등장성운동시능동보조운동으로시행하다가점차독립적으로시행해나갔다. 22 PBU (Chattanooga Stabilizer, Chattanooga Group Inc., USA) 를적용하여중간볼기근강화훈련을시행하는동안, 탄력주머니 (elastic bag) 222 www.kptjournal.org
Gluteus Medius Training Using PBU in Stroke JKPT A B C D Figure 1. Gluteus medius training in side lying position. (A) starting position for general gluteus medius training, (B) ending position for general gluteus medius training, (C) starting position for gluteus medius training using pressure biofeedback unit, (B) ending position for gluteus medius training using pressure biofeedback unit. 를매트와허리부분사이에놓고, 압력을 40 mmhg 까지부풀려이를표적압력으로하였다. 훈련중압력의감소는주머니와몸통이떨어져서움직이는것을나타내고압력의증가는주머니와몸통이밀착하여움직이는것을나타낸다. 대상자는 PBU의아날로그게이지를통해시각되먹임을제공받고, 엉덩관절을벌림하는동안표적압력을유지하여몸통의불필요한움직임을억제하도록하였다. 검사자는압력의변동을함께모니터하였다. 호흡으로인한압력의변화는오차범위 ± 5 mmhg로하였다 (Figure 1C, D). 14,21 4. 평가방법 1) 근력평가 (Muscle Strength Testing) 중간볼기근의근력은휴대용근력계 (Hand-held Dynamometer, JTech Medical, USA) 를이용하여, 엉덩관절벌림시등척성수축에대한근력을측정하였다. 본연구에서는연속 3회측정한값의평균을측정값으로사용하였다. 단위는뉴턴 (N) 으로기록하였다. 근피로도를피하기위해대상자들은각각의측정사이에 1분간의휴식을취하였다. 23 2) 근지구력평가 (Muscular Endurance Testing) 중간볼기근의근지구력은소렌슨검사 (Sorenson test) 24 의원리를이용하여측정하였다. 옆으로누운자세에서몸통을벨트로고정하고마비측엉덩관절을최대관절가동범위의중간위치에놓은자세에서다리가구부러지지않고수평면으로떨어질때까지의시간 (second) 을측정하였다. 본연구에서는연속 3회측정한값의평균을측정값으로사용하였다. 근피로도를피하기위해대상자들은각각의측정 사이에 1분간의휴식을취하였다. 25 3) 균형능력평가균형능력을평가하기위하여 BioRescue, 버그균형척도 (Berg Balance Scale, BBS), 옆으로팔뻗기검사 (Lateral Leach Test, LRT) 를이용하였다. BioRescue (RM ingenierie, France) 는정적자세조절능력을확인하기위해자세동요를측정하고, 동적자세조절능력을확인하기위해안정성한계를검사하는데사용하였다. BioRescue은 610 580 10 mmn의힘판과연결된컴퓨터및 93 52 cm 크기의모니터로구성되어있다. 힘판의압력감지기는총 1,600개로구성되어있으며, 압력감지기하나의크기는 10 10 mm이었다. 또한힘판의센서를통한데이터의표본수집률은 100 Hz로얻어지도록되어있다. 버그균형척도는균형에대한기능적수행의정도를측정하기위하여정적균형능력과동적균형능력을객관적으로평가하는척도로서측정자내신뢰도 r= 0.99와측정자간신뢰도 r= 0.98로신뢰도와타당도가인정된평가도구이다. 26,27 옆으로팔뻗기검사는기능적과제수행시의동적균형및유연성을측정할수있는검사로서안정성한계를평가한다. 측정자간신뢰도와측정자내신뢰도 (ICC 0.85) 가높은검사방법으로편마비환자의균형을평가하기에적합한평가도구로알려져있다. 28 본연구에서는연속 3회측정한값의평균을측정값으로사용하였다. 5. 자료분석본연구의분석방법으로 SPSS ver.19.0 프로그램을이용하였다. PBU www.kptjournal.org 223
JKPT The Journal of Korean Physical Therapy Jeong-Ju Park, et al. 중간볼기근강화군, 일반적중간볼기근강화군그리고대조군의그 룹과시점별근력, 근지구력그리고균형능력을비교분석하기위하여 이요인반복측정분산분석 (two-way ANOVA with repeated measurement) 을실시하였다. 또한중재별전후변화량의차이를알아보기위 해서일원배치분산분석을실시하였고, 사후검사는 Scheffe 검사로 실시하였다. 모든검사에서통계학적유의수준은 0.05 로하였다. 결과 1. 연구대상자의일반적특성 본연구에참여한연구대상자는총 27 명으로대상자의일반적특징 은 Table 1 과같았다. 세군간대상자의나이, 성별, 몸무게, 키, 발병기 간, 이환측, 한국판간이정신상태검사에서유의한차이가없었다 (p> 0.05) (Table 1). 2. 세군의중재전후및군간하지근기능비교 각집단의하지근기능을평가하기위해근력과근지구력을측정하 였다. 중재전후집단내근력을비교한결과 PBU 중간볼기근강화군 Table 1. General characteristics of subjects PBU Ex. (n=9) General Ex. (n=9) Control (n=9) χ 2 /F Age (year) 62.1±8.6 64.3±9.5 69.7±10.6 0.33 Gender (male/female) 6/3 3/6 5/4 0.35 Weight (kg) 68.2±7.2 66.8±8.0 64.2±8.4 0.54 Height (cm) 162.8±7.6 159.9±8.2 165.3±6.2 0.57 Time since stroke (month) 20.6±19.4 17.8±11.5 25.6±21.7 0.26 Affected side (left/right) 5/4 6/3 3/6 0.35 K-MMSE (score) 26.7±2.5 25.8±1.8 25.4±2.3 0.63 Values are mean±sd. PBU Ex., gluteus medius training using pressure biofeedback unit; General Ex., general gluteus medius training; Control, conventional physical therapy group; K-MMSE, Mini-Mental State Examination-Korean. 과일반적중간볼기근강화군에서는유의한증가를보였고 (p < 0.05), 대조군에서는유의한변화가없었다. 중재방법과측정시점의교호작용은유의한것으로나타났다 (F = 16.084, p < 0.05). 세집단간전후변화량차이를비교한결과집단간에유의한차이를보였다 (p < 0.05). 사후검정결과 PBU 중간볼기근강화군과일반적중간볼기근강화군이대조군에비하여유의한증가를보였다 (p < 0.05). 중재전후집단내근지구력을비교한결과 PBU 중간볼기근강화군에서유의한증가를보였고 (p < 0.05), 일반적중간볼기근강화군과대조군에서는유의한변화가없었다. 중재방법과측정시점의교호작용은유의한것으로나타났다 (F = 5.553, p < 0.05). 그리고세집단간전후변화량차이를비교한결과집단간에유의한차이를보였다 (p < 0.05). 사후검정결과 PBU 중간볼기근강화군이대조군에비하여유의한증가를보였다 (p< 0.05) (Table 2). 3. 세군의중재전후및군간균형능력비교각집단의균형능력을평가하기위해, 버그균형척도, 옆으로팔뻗기검사, 안정성한계속도를측정하였다. PBU 중간볼기근강화군, 일반적중간볼기근강화군에서중재전과비교하여중재후버그균형척도점수가유의하게증가하였으며 (p < 0.05), 옆으로팔뻗기검사는 PBU 중간볼기근강화군에서만유의한증가를보였다 (p < 0.05). 중재방법과측정시점의교호작용은유의하지않았다. 집단간중재전후의변화량을비교한결과유의한차이를보였다 (p < 0.05). 사후검정결과버그균형척도와옆으로팔뻗기검사모두 PBU 중간볼기근강화군이대조군에비하여유의한증가를보였다 (p < 0.05). 안정성한계검사에서중재전후측정값을비교한결과 PBU 중간볼기근강화군은마비측방향에서중재전 2.01에서중재후 1.36으로앞쪽방향에서중재전 1.79에서중재후 1.26으로통계적으로유의한속도감소를보였다 (p < 0.05). 중재방법과측정시점의교호작용은마비측방향 (F= 5.441, p< 0.05) 과앞쪽방향 (F=18.310, p< 0.05) 에서유의하게나타났다 (Tables 3, 4). Table 2. Comparison of muscle strength and endurance before and after gluteus medius training between the three groups PBU Ex. (n=9) General Ex. (n=9) Control (n=9) F Strength (N) Pre-test 22.64±4.83 15.66±5.15 17.21±5.82 Group 4.582 Post-test 29.54±6.13 22.10± 4.32 18.86± 5.55 Time 35.876 * Group Time 16.084 * Change 6.90±4.75 6.44±0.77 1.64±2.70 5.227 * Endurance (Sec) Pre-test 19.84±10.75 11.18± 11.28 12.73± 7.70 Group 5.500 * Post-test 38.44±20.05 19.91± 20.61 16.31± 11.43 Time 45.862 * Group Time 5.553 * Change 18.59±11.49 8.72±13.26 3.58±5.10 3.660 * Significant difference with General Ex.; Significant difference with Control. * p<0.05. PBU Ex., gluteus medius training using pressure biofeedback unit; General Ex., general gluteus medius training; Control, conventional physical therapy group. 224 www.kptjournal.org
Gluteus Medius Training Using PBU in Stroke JKPT Table 3. Comparison of balance ability before and after gluteus medius training between the three groups PBU Ex. (n=9) General Ex. (n=9) Control (n=9) F BBS (Score) Pre-test 46.43±7.68 38.29±13.49 44.71±5.22 Group 1.429 Post-test 50.14±4.81 39.86± 12.55 45.14± 5.08 Time 18.182 * Group Time 3.359 Change 3.71±3.55 1.57±1.40 0.43±0.79 3.858 * LRT (cm) Pre-test 12.93±1.47 11.73±3.56 11.11±2.38 Group 2.710 Post-test 15.03±1.72 12.63± 4.03 10.94± 3.18 Time 5.186 Group Time 2.407 Change 2.10±1.70 0.90±1.11-0.17± 1.92 3.480 * Significant difference with General Ex.; Significant difference with Control. * p<0.05. PBU Ex., gluteus medius training using pressure biofeedback unit; General Ex., general gluteus medius training; Control, conventional physical therapy group; BBS, Berg Balance Scale; LRT, Lateral Reach Test. Table 4. Comparison of LOS velocity before and after gluteus medius training between the three groups PBU Ex. (n=9) General Ex. (n=9) Control (n=9) F Paretic side velocity (cm/s) Pre-test 2.01±0.75 1.86±0.71 1.76±0.62 Group 0.298 Post-test 1.36±0.53 1.96±0.37 1.74±0.58 Time 2.959 Group Time 5.441 * Change -0.66±0.54 0.10±0.65-0.01± 0.30 4.314 * Non-paretic side velocity (cm/s) Pre-test 1.79±0.79 1.91±0.82 2.09±0.76 Group 0.042 Post-test 1.71±0.86 1.81±0.88 1.61±0.94 Time 1.162 Group Time 0.207 Change -0.07±0.59-0.10± 1.00-0.47± 0.16 0.385 Ant. Velocity (cm/s) Pre-test 1.79±0.53 1.67±0.58 2.16±0.81 Group 1.301 Post-test 1.26±0.47 1.70±0.48 1.57±0.62 Time 10.086 * Group Time 18.310 * Change -0.07±0.59-0.10± 1.01-0.47± 1.16 0.385 Post. Velocity (cm/s) Pre-test 1.56±0.52 2.00±0.95 2.06±1.01 Group 1.614 Post-test 1.36±0.57 1.51±0.48 1.69±0.54 Time 4.315 Group Time 0.263 Change -0.20±0.51-0.49± 0.65-0.37± 1.14 0.220 Significant difference with General Ex.; Significant difference with Control. * p<0.05. PBU Ex., gluteus medius training using pressure biofeedback unit; General Ex., general gluteus medius training; Control, conventional physical therapy group; LOS, limited of stability. 고찰본연구는뇌졸중환자의균형능력에있어필수적인중간볼기근의근기능회복을위하여중간볼기근강화훈련시압력바이오피드백기구를통한외재적피드백제공이뇌졸중환자의근력, 근지구력, 그리고균형능력향상에어떠한영향을미치는지알아보고자하였다. 일반적으로중간볼기근을강화시키기위해옆으로누운자세에서엉덩관절벌림운동을실시한다. 이자세는골반근육을강화시키는여러운동프로그램중가장높은중간볼기근활성도를보이는자세이며, 29 목표화된중간볼기근활성에효과적이라하였다. 14 본연구에서뇌졸중환자를대상으로옆으로누운자세에서중간볼기근강화 훈련을실시한결과중간볼기근근력과근지구력에서유의한향상을보였다 (p < 0.05). 옆으로누운자세에서엉덩관절벌림을통한중간볼기근강화훈련시흔히골반의가쪽기울임을이용한보상작용을경험하고지연된중간볼기근활성도를보인다. 중간볼기근의적절한동원을촉진시키기위한치료프로토콜이제시되어왔고, Cynn 등 21 에따르면압력바이오피드백기구를이용한허리부위안정화가같은쪽골반기울임을감소시켜중간볼기근활성도의유의한향상를가져왔다고하였다. Lee 등 30 은엉덩관절벌림시압력바이오피드백기구와골반벨트를적용한선택적중간볼기근강화가근활성도에유의한향상을보였다고하였다. 본연구에서 PBU 중간볼기근강화군과일반적중간볼기근강화군모두대조군에비해근력의유의한 www.kptjournal.org 225
JKPT The Journal of Korean Physical Therapy Jeong-Ju Park, et al. 증가를보였고, 특히 PBU 중간볼기근강화군은중재후근력과근지구력모두에서더큰변화량을보였다. 이러한결과는압력바이오피드백기구의사용이엉덩관절벌림시근활성도및골반가쪽기울임에미치는영향을알아본선행연구와유사한결과를보인다고할수있다. 21 따라서압력바이오피드백기구가뇌졸중환자에게몸통안정성에관한적절한피드백을제공했으며, 이를통해중간볼기근의목표화된훈련이가능했다고설명할수있다. 엉덩관절벌림근은보행시디딤기에몸통과하지의안정성을조절하는데중요한역할을하고, 벌림근의근력약화는관상면에서의안정성을감소시켜몸통의가쪽굽힘을일으키는원인이된다. 또한, 보행시신체균형을분석하였을때엉덩관절벌림근은관상면에서신체의가쪽균형유지에중요하다. 6 Kim 등 9 의연구에서탄력밴드를이용한엉덩관절벌림근강화운동은정적균형능력에영향을주었다. Powers 5 는뇌졸중환자의마비측엉덩관절벌림근의강화훈련이신체의가쪽면안정성을높여동적균형능력을증가시킨다고하였다. Mercer 등 10 은뇌졸중환자의엉덩관절벌림근강화운동이양하지의대칭적인체중이동을가능하게하고가쪽으로의균형조절능력를증가시켰다고보고하였다. 이러한연구들은뇌졸중환자의신체안정성에있어서엉덩관절벌림근이가쪽으로의몸통중심이동을가능하게하고가쪽균형능력에영향을주어환자의몸통조절의향상과균형능력에중요한역할을하는것을보여준다. 본연구에서버그균형척도, 옆으로팔뻗기검사는 PBU 중간볼기근강화군과일반적중간볼기근강화군내에서중재전 후모두유의하게증가된결과를나타내었다 (p < 0.05). 세집단간중재전후변화량을비교한결과, 버그균형척도와옆으로팔뻗기검사에서 PBU 중간볼기근강화군이가장높은변화량을보였다. 이결과를통해 PBU를적용한중간볼기근강화훈련이정적 동적균형에영향을미친다는결과를알수있다. 한편, 뇌졸중환자의운동학습과관련된외재적피드백사용에대한선행연구결과들은균형훈련시자신의체중분포에대한시각적피드백을제공받은경우균형능력이향상되는것으로나타났다. 31 Van Vliet 등 18 은시각적피드백이뇌졸중환자의균형능력을향상시켰다고하였고청각적피드백또한앉고일어서기 (sit-to-stand) 능력을향상시켰다고하였다. Thikey 등 16 은보행재활동안제공된조기시각적피드백제공이뇌졸중환자의움직임향상과함께재활시움직임에대한이해력을향상시켰다고하였다. 본연구에서는시각적피드백을제공한균형훈련을직접적으로시행하지않았으나압력바이오피드백기구를적용한피드백제공이세그룹간운동조절능력에어떠한영향을미쳤는지알아보기위해안정성한계속도를비교하였고그결과 PBU 중간볼기근강화군이훈련전후마비측과앞쪽방향으로유의한속도감소를보였다 (p < 0.05). 이러한결과는기존 의엉덩관절벌림근이디딤기에관상면과수평면에서의안정성을제 공함으로써몸통이앞쪽으로쏠리거나가쪽으로무너지지않도록 조절하는역할 4 을하는것을지지하는결과라고할수있다. 세집단 간중재전후변화량을비교한결과유의한차이는없었으나 PBU 중 간볼기근강화군이일반적중간볼기근강화군과대조군보다상당 한속도감소를보였다. 이러한결과는압력바이오피드백기구를적 용한중간볼기근강화훈련이마비측하지의움직임시적절한신경 근조절을통해안정성한계를넘어균형이무너지는것을미세하게 조절하는것이라고할수있다. 본연구의제한점은연구대상자수가적고중재기간이짧아모든 뇌졸중환자들에게일반화시키기어려웠다. 또한추적연구가이루어 지지않아효과가지속되었는지확인하지못하였으며생체역학적 변수를검사하지못하였다. 따라서앞으로의연구에서는많은대상 자들을모집하여압력바이오피드백기구를적용한중간볼기근강 화훈련이관절각도, 근활성도, 근피로도평가와같은생체역학적인 변수에미치는영향에관한연구가필요하겠다. 본연구에서는 PBU 중간볼기근강화군이일반적중간볼기근강 화군과대조군보다중간볼기근의근력, 근지구력에유의한향상을 가져왔고버그균형척도와옆으로팔뻗기검사에서유의한증가를 보이면서정적, 동적균형능력의향상을보였다. 또한 PBU 중간볼기 근강화군은중재전후유의한안정성한계속도감소를보였다. 그룹 간유의한차이는없었으나상당한속도감소를보이면서신경근조 절능력의향상을보였다. 이러한결과를통해뇌졸중환자에게하지 근기능과균형능력향상을위해압력바이오피드백기구를이용한 선택적중간볼기근강화가효과적이라고제안할수있겠다. REFERENCES 1. Canning B, Sanchez G. Considering powered mobility for individuals with stroke. Top Stroke Rehabil. 2004;11(2):84-8. 2. Bobath B. Adult hemiplegia, evaluation and treatment. 3rd ed. London, Butterworth-Heinemann, 1990:16-57. 3. Yang DJ, Park SK, Kang JI et al. Effects of changes in postural alignment on foot pressure and balance of patients with stroke. J Kor Phys Ther. 2014;26(4):226-33. 4. Neumann DA. Kinesiology of the musculoskeletal system, foundations for rehabilitation. 2nd ed. St. Louis, Missouri, Mosby, 2010:465-519. 5. Powers CM. The influence of abnormal hip mechanics on knee injury, a biomechanical perspective. J Orthop Sports Phys Ther. 2010;40(2):42-51. 6. Sahrmann S. Diagnosis and treatment of movement impairment syndromes. St. Louis, Missouri, Mosby, 2002:121-90. 7. Granat MH, Maxwell DJ, Ferguson AC et al. Peroneal stimulator, evaluation for the correction of spastic drop foot in hemiplegia. Arch Phys Med Rehabil. 1996;77(1):19-24. 8. Smith L, Weiss E, Lehmkuhl LD. Brunnstrom s clinical kinesiology. 226 www.kptjournal.org
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