The Asian Journal of Kinesiology Original Research Effects of Combined Training on Isokinetic Strength of Ankle, Knee, Lumbar and Shoulder in Female Professional Volleyball Players Jong-Hak Lee 1, Ho-Seong Lee 1, Jae-Chung Ghil 2* 1 Dankook University 2 Korea University Received: October 31, 2018 Accepted: December 18, 2018 Published online: January 31, 2019 Keywords: Combined Training Isokinetic Strength Professional Volleyball Players ABSTRACT OBJECTIVES The purpose of this study was to investigate the effects of combined training on isokinetic strength of ankle, knee, lumbar and shoulder in female professional volleyball players. METHODS Twenty-five female professional volleyball players were divided to combined training group (CTG, n=14) and control group (CON, n=11). Combined training was performed for 70 min/day (warm-up; 15 min, plyometric training; 20 min, core balance training; 20 min, cool-down; 15 min), 2 times a week for 8 weeks. Isokinetic strength for each region measured before and 8 weeks after combined training. RESUS In peak torque, right ankle evertor and invertor, left ankle evertor and invertor, right knee and, left knee and, lumbar and, right shoulder internal rotator, left shoulder internal rotator were statistical significant interactions between G, T and G T, respectively. In peak torque/body weight, right ankle evertor and invertor, left ankle evertor and invertor, right knee and, left knee and, lumbar and, right shoulder external rotator and internal rotator and left shoulder internal rotator were statistical significant interactions between G, T and G T, respectively. In total work, right ankle evertor and invertor, left ankle invertor, right knee and, left knee, lumbar and, right shoulder external rotator and internal rotator, left shoulder external rotator and internal rotator were statistical significant interactions between G, T and G T, respectively. CONCLUSIONS We demonstrated that combined training increases the isokinetic strength of ankle, knee, lumbar and shoulder in professional female volleyball athletes. The Asian Society of Kinesiology and the Korean Academy of Kinesiology 서론 배구는빠른전신반응시간과강력한스파이크와블로킹을위한폭발적인힘이요구되어높은상 하체의근력, 순발력, 지구력, 유연성및유산소성능력이고루요구되는스포츠이다 [1]. 스포츠현장에서는배구선수의경기력향상과부상예방및선수의컨디션을최상으로 *Correspondence: Jae-Chung Ghil, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul, Republic of Korea; Tel: +82-10-4242-3228; Fax: +02-770-5418; Email: pss3228@ korea.kr 증진시키기위하여다양하고과학적인훈련방법을개발하여왔을뿐만아니라개발된훈련방법중에서가장효과적이고목적에부합한훈련결과를입증하기위해많은노력을하고있다. 그중에서플라이오메트릭훈련 (plyometric training) 은반복적인근육의신장-반사점프동작이많은구기종목의대표적인훈련방법이며 [2-3], 기존에는점프력을중심으로다리의근육강화에초점이맞춰져있지만, 최근에는전신의복합적인근력발달을위 This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by-nc/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 1
한훈련방법으로진행되고있기때문에배구종목에폭넓게적용되고있다 [4]. 또한배구선수는스파이크와서브동작의특성때문에팔 다리의각근력과근파워, 허리를중심으로팔 다리의순발력및점프능력이경기력과밀접한관련성이있다고보고하였다 [5]. 따라서배구선수를대상으로플라이오매트릭훈련을적용하여팔 다리의각근력등의등속성근력을평가할필요가있다고생각된다. 이외에도몸통균형훈련 (core balance training) 은신체의중심, 즉엉덩허리근 (iliopsoas muscle), 척주세움근 (erector spinae muscle), 가시사이근 (interspinales muscle), 넓은등근 (latissimus dorsi muscle), 가로돌기사이근 (intertransversii muscle), 허리네모근 (quadratus lumborum muscle), 뭇갈래근 (multifidus muscle), 배근육 (abdominal muscle) 및등허리근막 (lumbodorsal fascia) 근육의움직임을안정화시키고, Co-activation을시키면서척추의안정성을유지하는훈련방법이다 [6]. 또한몸통균형훈련은주로불안정한지면을이용하여허리안정화와균형을동시에향상시킬수있다는장점이있으며, 이는점프와착지를반복하며높은동적균형능력을필요로하는배구선수에게필요한훈련이라고보고하였다 [6]. 따라서배구선수의신체의안정적인움직임을위해서는몸통균형훈련을적용할필요가있다고생각된다. 특히, 배구의스파이크동작은점프및착지시다리의근력, 유연성및평형성이요구되며 [7], 무릎부터발목과허리및어깨관절로연결되는부위의근력을폭발적으로사용하여빠른시간내에강한힘을필요로하기때문에각관절의조정능력및등속성근력을평가하는것은부상예방및기능발달에도움이될것으로생각된다 [8]. 선행연구에의하면, 배구선수는점프및방향전환시편측부하상태로신체를지지하게되는데, 이 때부족한다리의근력은신체의움직임에필요한동작을제공하지못하게되면서부상의위험률이높아질수있다고하였다 [9]. 또한배구선수는서브와스파이크를수행하는동안가속과감속을반복하여어깨관절에강한수축력이발생하기때문에충분한어깨관절의내 외회전근력이필요하다고보고하였다 [10]. 특히, 배구선수는스파이크동작시다리와허리및어깨관절의근력을연쇄적으로사용하기때문에각관절을효율적으로이용하여전신의근력을폭발적으로발휘할필요가있다고보고하였다 [11]. 따라서각관절의움직임에따른근력, 최대근력과절대근력및총일량등의등속성근력을상세히검토할필요가있다고생각된다. 이에이연구에서는플라이오메트릭훈련과몸통균형훈련의복합훈련이발목, 무릎, 허리및어깨관절의등속성근력을향상시킬수있다는가설을세우고, 이러한가설을검증하기위하여실제로여자프로배구선수를대상으로 8주간의복합훈련이각관절의등속성근력에어떠한영향을주는지를밝히고자하였다. 연구방법연구대상은한국배구연맹 (Korean Volleyball Federation; KOVA) 과대한배구협회 (Korea Volleyball Association; KVA) 에소속된여자프로배구 2팀선수총 25명을 1개팀은복합훈련을실시한집단 (combined training group; CTG, n = 14) 및다른 1개팀은복합훈련을실시하지않는집단 (control group; CON, n = 11) 으로분류하였다. 모든피험자에게는연구의취지내용을충분히설명한후에참가동의를얻었으며, 병력, 건강상태, 수술경력및손상이없는자로선정하였다. 연구대상의신체적특성은다음과같다 <Table 1>. Table 1. Physical characteristics of the subjects. group age (yrs) height (cm) weight (kg) BMI (kg/m 2 ) career (yrs) positions CTG (14) 22.5±2.74 177.7±7.93 65.9±5.55 18.5±1.26 7.5±1.50 center (3), wing spiker (6), setter (3), libero (2) CON (11) 23.4±3.56 176.5±6.95 66.9±7.61 18.9±1.76 8.0±2.10 center (2), wing spiker (5), setter (2), libero (2) means ± SD, CTG: Combined Training Group, CON: Control Group 2 The Asian Journal of Kinesiology
측정항목등속성근력은 isokinetic dynamometer (BIODEX system 3 pro, BIODEX, USA) 및측정부착물을활용하여오른쪽 (Rt) 과왼쪽 (Lt) 의양측발목, 무릎, 허리및어깨관절의최대우력 (peak torque), 체중당최대값 (peak torque % body weight) 및총일량 (total work) 을 BIODEX 사용자매뉴얼에근거하여측정하였다 [12-14]. 각관절의각속도는 60 /sec에서 3회의연습을실시한후에 4회의검사를실시하여최대값을채택하였다. 각관절의구체적인측정방법은다음과같다. 발목관절의등속성근력은의자를 90 로회전시켜등받이를 70 기울인후의자앞받침대튜브 (receiving tube) 에 T-Bar를포함한다리서포트패드 (limb support pad) 를설치하고넙다리뼈 (femur) 의먼쪽아래에서포트패드를놓고넙다리뼈를스트랩으로고정하여동력계를 0 로회전시키고 60-70 기울여정강뼈 (tibia) 의발목안쪽번짐 / 가쪽번짐의측정부착물을설치하였다. 이후정강뼈몸통 (tibia shaft) 과동력계의축이일치하도록기기를조정하였으며, 스트랩으로발을고정하여상체및반대엉덩관절 (hip joint) 과넙다리뼈를고정시켜외력의힘이작용하지않도록하였다. 검사각도는중립자세를기준으로안쪽번짐 30 및가쪽번짐 20 로제한하여설정하였다. 무릎관절의등속성근력은동력계의축이피험자의무릎관절회전축인넙다리가쪽관절융기 (lateral femoral condyle) 에일치하도록기기를조정하였으며, 상체및엉덩관절과넙다리뼈를고정시켜외력의힘이작용하지않도록하였다. 검사각도는 0-90 로제한하여설정하였고검사시무릎관절다리의무게가무릎관절최대우력에영향을주는것을막기위하여 gravity effect torque를측정하여입력하였다. 허리관절의등속성근력은동력계의균형조정다이얼을사용하여수직위치에서허리관절의 폄과굽힘측정부착물의균형을맞추어연결하였고부착물의시트가 15 기울어진상태를확인하였으며, 허리와엉치패드, 다리압박장치가분리되어각각의홀더에위치하고있는지를확인하였다. 또한부착물의고정축과척추수직축 (longitudinal spinal axis) 에일치하도록측정기기의의자에앉아기기축과위앞엉덩뼈가시 (anterior superior ileac spines; ASIS) 를일치시켰으며넙다리뼈와평행한위치에발판을배치하여무릎관절이 15 굽힘된 Semi-standing 자세에서측정하였다. 이때어깨뼈롤 (scapula roll) 을조정하여어깨뼈패드를어깨뼈에위치하고필요한경우목뼈받침을조정하여최대한안정된상태에서측정에임할수있도록하였다. 상체와엉덩관절및넙다리뼈는스트랩으로고정시켜외력의힘이작용하지않도록하였다. 검사각도는 20-100 사이의범위이내에서통증이없는75-80 의운동범위로제한하여설정하였다. 어깨관절의등속성근력은의자를 15 회전시키고동력계를반대쪽으로 20 회전시킨다음 50 기울여준비하고, 피험자의팔꿈치관절은 90 구부린상태에서어깨관절의측정부착물에위치하여어깨관절이움직이지않도록스트랩으로고정시켜서측정을실시하였다. 검사각도는중립자세를기준으로안쪽돌림 45 및바깥돌림 25 로제한하여설정하였다. 배구훈련이연구에참여한모든여자배구선수의일상적인배구훈련은프로배구시즌이끝난시점부터 4주간의충분한휴식을취한후에 1일 90분 ( 준비운동 20분, 본운동 50분및정리운동 20분 ) 의기본기술및체력훈련을주 4회실시하였고, 주 1회의연습경기훈련 ( 약 40 분정도 ) 을 8주간에걸쳐서실시하였으며 <Table 2>, 각팀의운동강도및훈련순서는통제하지못하였다. Table 2. Volleyball training. division variety frequency time warm-up stretching, running 5 time/week 20 min volleyball training volleyball skill training, team play (spike, toss, pass, serve, receive, etc.) 4 time/week 50 min cool-down stretching, running 5 time/week 20 min 3
Table 3. Combined training. index variety time training volume warm-up stretching & running 15 min plyometric training bilateral jump (without bending knees) for one stair bilateral jump (with bending knees) and as far as possible unilateral jump short and as fast as possible lateral jump over barrier (2 inch) 20 min 1~3 week: 20 rep x 2 set 4~6 week: 25 rep x 2 set 7~8 week: 20 rep x 3 set 1~5 week: 10 rep x 2 set 6~8 week: 10 rep x 3 set 1~5 week: 10 rep x 3 set 6~8 week: 10 rep x 2 set 1~8 week: 10 rep x 2 set medicine ball throwing unilateral medicine ball throwing 1~5 week: 1 kg x 8 rep x 3 set 6~8 week: 2 kg x 6 rep x 2 set 1~5 week: 1 kg x 4 rep x 3 set 6~8 week: 1 kg x 8 rep x 2 set rest : 30 sec between sets and 1 min between training core balance training plank (with swiss ball) 20 min 1~3 week: 70 sec x 2 set 4~6 week: 90 sec x 2 set 7~8 week: 110 sec x 2 set push up 1 (with swiss ball) push up 2 (with swiss ball) leg raise (with swiss ball) 1~8 week: 10 rep x 2 set jack knife (with swiss ball) trampoline jump landing (4 directional) cool-down stretching & running 15 min 복합훈련이연구에서복합훈련은플라이오메트릭훈련과몸통균형훈련 (core balance training) 으로써, 플라이오메트릭훈련은 plyometric and ball throwing exercises protocol[15] 를근거로이연구에맞게수정및보완하여사용하였으며, 주로다리와팔의근력및근파워향상을목적으로적용하였다 <Table 3>. 플라이오메트릭훈련중 bilateral jump (without bending knees) for one stair 동작은무릎폄상태에서의자를밟으면서양발로점프하는동작이며, bilateral jump (with bending knees) and as far as possible 동작은무릎의폄과굽힘을사용하여양발로최대한멀리점프하는동작이다. 또한, unilateral jump short and as fast as possible 동작은한발로짧은거리와최대한먼거리를반복하는동작이며, lateral jump over barrier (2 inch) 동작은 2 inch의미니허들을이용하여좌 우측면으로허들 을연속적으로넘는동작이다. Medicine ball throwing 은 1~2kg의메디신볼을양손을이용하여정면으로던지는동작이며, unilateral medicine ball throwing 동작은메디신볼을한손으로이용하여던지는동작이다. 몸통균형훈련은배구선수의몸통균형훈련의선행연구를근거로이연구에맞게수정및보완하여몸통안정성, 고유감각기의활성, 유연성의개선등기능성움직임의개선과부상예방을목적으로적용하였다 [16]. 몸통균형훈련중 plank (with swiss ball) 동작은팔꿈치를스위스볼에올려놓고양발은바닥에둔채어깨에서발까지일직선이되도록유지하는자세이다. Push up 1 (with swiss ball) 동작은스위스볼에발을올리고팔꿈치를구부리면서상체를아래로내리는동작이며, push up 2 (with swiss ball) 동작은스위스볼에손을올린뒤팔꿈치를구부려몸을내리고, 팔꿈치를펴면서머리와어깨를들어올리는동작이다. leg raise 4 The Asian Journal of Kinesiology
Table 4. Changes in isokinetic strength of ankle before (pre) and after 8 weeks (post) combined exercise. Index variety group pre post F peak torque CTG 27.21±8.35 30.15±8.06 G 1.105 T 15.033* evertor CON 24.92±8.32 25.47±7.91 GxT 7.016** G 0.204 CTG 28.70±7.81 30.53±7.74 T 3.164 CON 28.49±6.21 28.24±4.77 GxT 5.538* CTG 27.65±4.87 29.85±5.61 G 1.344 T 0.903 invertor CON 26.72±6.20 25.43±6.45 GxT 13.320** G 3.972 CTG 25.28±7.08 28.82±7.10 T 8.848** CON 21.22±7.22 21.69±6.74 GxT 5.168* peak torque % body weight CTG 18.85±5.38 21.25±5.65 G 2.026 T 17.032*** evertor CON 16.80±4.99 17.26±4.84 GxT 7.891* G 0.46 CTG 19.954±5.46 21.47±5.28 T 5.313* CON 19.50±4.07 19.34±3.43 GxT 8.197** CTG 19.19±3.39 21.02±4.29 G 2.217 T 1.463 invertor CON 18.28±3.99 17.30±3.83 GxT 15.617** G 7.330* CTG 17.39±4.29 20.13±4.51 T 10.206** CON 14.29±3.93 14.56±3.31 GxT 6.851** total work CTG 60.66±22.33 66.96±17.55 G 0.369 T 9.829** evertor CON 58.32±20.38 59.20±21.58 GxT 5.595* G 0.047 CTG 67.11±18.18 66.27±14.40 T 1.028 CON 69.42±17.08 66.87±17.72 GxT 0.261 CTG 64.57±18.96 69.47±14.93 G 0.631 T 0.233 invertor means ± SD. *p <.05, **p <.01, ***p <.001 CON 63.56±16.84 59.91±14.97 GxT 10.820** G 3.722 CTG 58.74±19.95 66.75±21.11 T 9.647** CON 46.77±15.80 50.84±14.32 GxT 1.030 5
(with swiss ball) 동작은스위스볼을허벅지안쪽으로위치시킨뒤허리가뜨지않는선에서다리를위 아래로내리는동작이며, jack knife (with swiss ball) 동작은양발은스위스볼에, 양팔은바닥에위치시킨후무릎을굽혀스위스볼을당기는동작이다. Trampoline jump landing (4 directional) 동작은트램폴린위에서양두발로위 아래 좌 우를번갈아가며점프하는동작이다. 복합훈련은 1일 70분간, 주 2회를 8주간에걸쳐실시하였다. 훈련의구성은 15분간의스트레칭과달리기, 본운동은플라이오메트릭 20분및몸통균형훈련 20분으로총 40분에걸쳐서실시하였으며, 정리운동은 15분간스트레칭과달리기를실시하였다. 세트간휴식시간은 30초및운동간휴식시간은 1분으로설정하였다 <Table 3>. 통계분석이연구에서수집된모든자료는 SPSS-WIN Ver 18.0을이용하여평균과표준편차를산출하였고, 연구가설을통계학적으로검정하기위하여이원분산분석 (Two-way ANOVA) 을실시하였다. 통계적유의수준은 α=.05로설정하였다. 결과발목관절의등속성근력발목관절의등속성근력의변화는 <Table 4> 에제시하였다. 오른쪽발목가쪽번짐근의최대우력은시기 (p=.015), 집단및시기 (p=.001) 간에각각통계학적으로유의한상호작용효과가나타났으며, 왼쪽발목가쪽번짐근의최대우력은집단및시기 (p=.028) 간에통계학적으로유의한상호작용효과가나타났다. 또한, 오른쪽발목안쪽번짐근의최대우력은집단및시기 (p=.001) 간에통계학적으로유의한상호작용효과가나타났으며, 왼쪽발목안쪽번짐근의최대우력은시기 (p=.007), 집단및시기 (p=.033) 간에각각통계학적으로유의한상호작용효과가나타났다. 오른쪽발목가쪽번짐근의체중당최대값은시기 (p=.000), 집단및시기 (p=.001) 간에각각통계학적으로유의한상호작용효과가나타났으며, 왼쪽발목가쪽번짐근의체중당최대값은시기 (p=.031), 집단및시기 (p=.009) 간에각각통계학적으로유의한상호작용효과가나타났다. 또한, 오른쪽발목안쪽번짐근의체중당최대값은집단및시 기 (p=.001) 간에통계학적으로유의한상호작용효과가나타났으며, 왼쪽발목안쪽번짐근의체중당최대값은집단 (p=.013), 시기 (p=.004), 집단및시기 (p=.016) 간에각각통계학적으로유의한상호작용효과가나타났다. 오른쪽발목가쪽번짐근의총일량 (total work) 은시기 (p=.005), 집단및시기 (p=.027) 간에각각통계학적으로유의한상호작용효과가나타났다. 또한, 오른쪽발목안쪽번짐근의총일량은집단및시기 (p=.003) 간에통계학적으로유의한상호작용효과가나타났으며, 왼쪽발목안쪽번짐근의총일량은시기 (p=.005) 간에통계학적으로유의한상호작용효과가나타났다. 무릎관절의등속성근력무릎관절의등속성근력의변화는 <Table 5> 에제시하였다오른쪽무릎폄근의최대우력은시기 (p=.000), 집단및시기 (p=.000) 간에각각통계학적으로유의한상호작용효과가나타났으며, 왼쪽무릎폄근의최대우력은시기 (p=.006), 집단및시기 (p=.006) 간에통계학적으로유의한상호작용효과가나타났다. 또한, 오른쪽무릎굽힘근의최대우력은시기 (p=.008), 집단및시기 (p=.002) 간에통계학적으로유의한상호작용효과가나타났으며, 왼쪽무릎굽힘근의최대우력은시기 (p=.000), 집단및시기 (p=.021) 간에각각통계학적으로유의한상호작용효과가나타났다. 오른쪽무릎폄근의체중당최대값은시기 (p=.000), 집단및시기 (p=.000) 간에각각통계학적으로도유의한상호작용효과가나타났으며, 왼쪽무릎폄근의체중당최대값은시기 (p=.004), 집단및시기 (p=.003) 간에통계학적으로유의한상호작용효과가나타났다. 또한, 오른쪽무릎굽힘근의체중당최대값은시기 (p=.003). 집단및시기 (p=.001) 간에각각통계학적으로유의한상호작용효과가나타났으며, 왼쪽무릎굽힘근의체중당최대값은시기 (p=.000), 집단및시기 (p=.005) 간에통계학적으로유의한상호작용효과가나타났다. 오른쪽무릎폄근의총일량은시기 (p=.004), 집단및시기 (p=.017) 간에각각통계학적으로유의한상호작용효과가나타났다. 또한, 오른쪽무릎굽힘근의총일량은시기 (p=.001), 집단및시기 (p=.05) 간에각각통계학적으로유의한상호작용효과가나타났으며, 왼쪽무릎굽힘근의총일량은시기 (p=.003) 간에통계학적으로유의한상호작용효과가나타났다. 6 The Asian Journal of Kinesiology
Table 5. Changes in isokinetic strength of knee before (pre) and after 8 weeks (post) combined exercise. Index variety group pre post F peak torque CTG 86.03±16.94 99.87±15.19 G 0.929 T 38.464*** CON 85.73±15.21 88.07±14.97 GxT 19.397*** G 0.035 CTG 89.29±13.31 97.51±13.48 T 10.507** CON 91.58±10.52 91.44±10.57 GxT 11.123** CTG 40.29±6.37 45.85±7.09 G 0.048 T 11.255** CON 42.74±6.54 42.23±7.23 GxT 16.240** G 1.023 CTG 42.17±6.64 46.38±7.84 T 27.113*** CON 40.76±7.28 41.80±7.56 GxT 9.825** peak torque % body weight CTG 86.03±16.94 99.87±15.19 G 0.929 T 38.464*** CON 85.73±15.21 88.07±14.97 GxT 19.397*** G 0.035 CTG 89.29±13.31 97.51±13.48 T 10.507** CON 91.58±10.52 91.44±10.57 GxT 11.123** CTG 40.29±6.37 45.85±7.09 G 0.048 T 11.255** CON 42.74±6.54 42.23±7.23 GxT 16.240** G 1.023 CTG 42.17±6.64 46.38±7.84 T 27.113*** CON 40.76±7.28 41.80±7.56 GxT 9.825** total work CTG 428.23±152.21 539.09±88.71 G 0.316 T 10.425** CON 503.73±126.48 516.22±117.31 GxT 6.630* G 0.709 CTG 430.77±142.02 511.15±159.17 T 3.091 CON 496.55±90.50 518.79±96.90 GxT 0.992 CTG 242.86±68.70 282.64±58.01 G 1.257 T 13.847** means ± SD. *p <.05, **p <.01, ***p <.001 CON 288.64±79.17 299.94±77.56 GxT 4.304* G 0.293 CTG 253.85±72.73 282.45±63.30 T 10.786** CON 272.27±77.61 294.78±74.83 GxT 0.153 7
Table 6. Changes in isokinetic strength of lumbar before (pre) and after 8 weeks (post) combined exercise. Index group pre post F peak torque CTG 165.3±31.71 201.56±43.03 G 10.905** T 9.565** CON 141.87±28.28 142.51±30.23 GxT 8.917** CTG 97.31±15.49 116.66±21.77 G 1.595 T 17.448*** CON 96.20±24.70 96.46±25.24 GxT 16.554*** peak torque % body weight CTG 114.43±23.11 141.85±30.15 G 16.717*** T 10.309** CON 95.96±13.22 96.38±14.64 GxT 9.699** CTG 67.57±9.37 81.83±13.55 G 2.805 T 21.573*** CON 65.61±16.70 65.66±16.30 GxT 21.246*** total work CTG 517.01±85.73 668.02±134.96 G 2.869 T 19.375*** CON 518.05±120.17 519.76±199.92 GxT 18.513*** CTG 302.02±68.01 392.97±76.10 G 0.038 T 18.640*** CON 340.30±112.14 341.01±110.04 GxT 18.068*** means ± SD. *p <.05, **p <.01, ***p <.001 허리관절의등속성근력허리관절의등속성근력의변화는 <Table 6> 에제시하였다허리폄근의최대우력은집단 (p=.003), 시기 (p=.005), 집단및시기 (p=.007) 간에각각통계학적으로유의한상호작용효과가나타났으며, 허리굽힘근의최대우력은시기 (p=.000), 집단및시기 (p=.000) 간에통계학적으로유의한상호작용효과가나타났다. 허리폄근의체중당최대값은집단 (p=.000), 시기 (p=.004), 집단및시기 (p=.005) 간에각각통계학적으로유의한상호작용효과가나타났으며, 허리굽힘근의체중당최대값은시기 (p=.000), 집단및시기 (p=.000) 간에각각통계학적으로유의한상호작용효과가나타났다. 허리폄근의총일량은시기 (p=.000), 집단및시기 (p=.000) 간에각각통계학적으로유의한상호작용효과가나타났으며, 허리굽힘근의총일량은시기 (p=.000), 집단및시기 (p=.000) 간에통계학적으로유의한상호작용효과가나타났다. 어깨관절의등속성근력어깨관절의등속성근력의변화는 <Table 7> 에제시하였다. 오른쪽어깨안쪽돌림근의최대우력은집단 (p=.002), 시기 (p=.001), 집단및시기 (p=.002) 간에각각통계학적으로유의한상호작용효과가나타났으며, 왼쪽어깨안쪽돌림근의최대우력은집단 (p=.008) 간에통계적으로유의한상호작용효과가나타났다. 오른쪽어깨바깥돌림근의체중당최대값은시기 (p=.000), 집단및시기 (p=.001) 간에각각통계학적으로유의한상호작용효과가나타났다. 또한, 오른쪽어깨안쪽돌림근의체중당최대값은집단 (p=.000), 시기 (p=.000), 집단및시기 (p=.000) 간에각각통계학적으로유의한상호작용효과가나타났으며, 왼쪽어깨안쪽돌림근의체중당최대값은집단 (p=.001), 시기 (p=.013), 집단및시기간 (p=.025) 에각각통계적으로유의한효과가나타났다. 오른쪽어깨바깥돌림근의총일량은시기 (p=.015) 간에통계적으로유의한효과가나타났으며, 왼쪽어 8 The Asian Journal of Kinesiology
Table 7. Changes in isokinetic strength of shoulder before (pre) and after 8 weeks (post) combined exercise. Index variety group pre post F peak torque CTG 15.67±2.65 17.23±4.67 G 0.341 T 1.82 CON 15.50±3.47 15.78±3.72 GxT 0.877 G 0.604 CTG 15.33±5.84 16.43±3.02 T 0.469 CON 14.61±3.89 14.63±4.05 GxT 0.439 CTG 21.22±4.54 28.97±4.28 G 12.926** T 14.609** CON 21.61±4.06 21.7±4.40 GxT 11.865** G 8.481** CTG 26.98±3.71 28.08±3.43 T 3.792 CON 21.64±6.17 21.72±5.79 GxT 2.821 peak torque % body weight CTG 10.56±4.21 12.03±3.36 G 0.290 T 22.818*** CON 10.51±2.03 10.69±2.21 GxT 13.901** G 1.969 CTG 10.758±2.01 11.47±2.31 T 3.037 CON 9.84±2.20 9.86±2.33 GxT 2.604 CTG 18.689±3.29 20.18±3.24 G 16.688*** T 19.457*** CON 14.664±2.16 14.69±2.18 GxT 18.085*** G 14.891** CTG 15.82±2.69 19.57±2.55 T 7.379* CON 14.58±3.09 14.65±2.85 GxT 5.789* total work CTG 47.38±13.13 51.20±9.66 G 0.173 T 6.998* CON 51.06±14.28 51.91±14.07 GxT 2.848 G 0.047 CTG 46.97±8.18 50.49±9.83 T 5.789* CON 47.51±13.86 47.84±14.77 GxT 3.989 CTG 96.87±16.94 103.94±13.12 G 9.216** T 5.394* means ± SD. *p <.05, **p <.01, ***p <.001 CON 80.58±17.09 80.62±16.90 GxT 5.284* G 7.118* CTG 96.22±14.16 101.58±13.09 T 1.807 CON 79.16±24.36 78.45±20.92 GxT 3.075 9
깨바깥돌림근의총일량은시기 (p=.025) 간에통계적으로유의한효과가나타났다. 또한, 오른쪽어깨안쪽돌림근의총일량은집단 (p=.006), 시기 (p=.03), 집단및시기 (p=.032) 간에각각통계학적으로유의한상호작용효과가나타났으며, 왼쪽어깨안쪽돌림근의총일량은집단 (p=.014) 간에통계학적으로유의한상호작용효과가나타났다. 논의이연구에서는복합훈련이여자프로배구선수의발목, 무릎, 허리및어깨관절의등속성근력에미치는영향을총체적으로검토한결과, 8주간의복합훈련, 즉팔과다리중심의플라이오메트릭훈련과허리중심의몸통균형훈련이여자프로배구선수의각관절의등속성근력을향상시켰다는사실을검증하였다. 따라서이연구의가설이성립되었다고할수있다. 일반적으로, 등속성근력은최대힘을발휘하여측정하였을경우근기능을객관적으로평가할수있으며, 설정된각속도별최대우력과체중당최대값및총일량등으로평가할수있다 [12]. 이연구에서최대우력은하나의근육군에대한전체의관절가동범위내에발휘된우력곡선의가장높은지점으로써절대적근력을의미하기때문에매우중요하다고할수있다 [12-14]. Wilkerson et al. [17] 은여성농구선수들을대상으로 6주간의플라이오메트릭훈련을실시한결과, 점프후착지동작에서편심성감속시무릎관절의안정성을강화하는넙다리뒤근 (hamstring) 과넙다리네갈래근 (quadriceps) 의비율이향상되었다고보고하였다. 따라서이연구에서플라이오메트릭훈련은여자프로배구선수의상대적근력, 즉순간적으로근육을이완시키면서착지시중력가속도에의해지면반작용만큼의부하를받아수축이일어나는최대우력이증가하였다고생각된다. 이연구에서체중당최대값은최대우력을체중으로나눈값으로써, Perrin[18] 은최대우력은근육의절대적근력혹은최대근력으로써총체중으로나눌경우상대적평가도가능하다고보고하였다. Fillyaw et al. [19] 은최대우력이연령, 성별, 체중, 각속도와중력등에영향을받기때문에체중당최대값과총일량의변화도함께검토할필요가있다고보고하였다. 선행연구에의하면, Kim & Chung [20] 은여자프로골퍼를대상으로 12주간의몸통균형훈련을실시한결과, 허리근력이향상되었다고보고하였고, Vladan et al. [21] 은배구선수를대상으로 6주간의점프운동만으로구성된플라이오메트릭훈련을진행한결과, 다리의등속성근력과점프능력이향상되었다고보고하였다. 이연구에서플라이오메트릭훈련과몸통균형훈련의복합훈련은여자프로배구선수의발목, 무릎, 허리및어깨관절등의각관절의체중당최대값이유의하게증가한것으로나타났다. 이것은플라이오메트릭훈련과몸통균형훈련, 즉반복적인신전-반사및코어안정화를통해최단시간동안힘이발휘되는근육의힘생성률 (rate of force production) 이증가하였기때문일가능성이있다고생각된다 [21]. 이연구에서총일량은반복운동중에발휘된힘의총량으로써, 관절의전체가동범위에서발현된근력을제시하였다 [12]. Lee et al. [22] 은 20대젊은여성을대상으로몸통균형훈련과다리근력운동을복합한필라테스훈련을 8주간에걸쳐서실시한결과, 무릎관절의총일량이증가하였으며, Koh[23] 는남자고등학교씨름선수를대상으로근력훈련과플라이오메트릭훈련의복합훈련을 12주간에걸쳐서실시한결과, 무릎과허리관절의총일량이유의하게증가하였다고보고하였다. 또한 Lee & Lee [24] 의연구에의하면, 남자대학생을대상으로 8주간의플라이오메트릭훈련을실시한결과, 발목과무릎관절의총일량이점진적으로증가하는경향을보였다고보고하였다. 이연구에서도복합훈련이여자프로배구선수의각관절의총일량을증가시켰다는사실을확인하였으며, 이러한증가는점프훈련과메디신볼을이용한플라이오메트릭훈련, 그리고전신몸통강화운동과스위스볼을이용한몸통균형훈련이주효과로작용하였을가능성이있다고추측된다. 하지만이러한각각의훈련효과에대해서명확하게구분할수없으며, 총체적인복합훈련의효과라고생각된다. 한편, 배구경기중주된득점기술인스파이크는순간적인이동동작과높은점프를기본으로수행하기때문에다리의근력이동작의효율성과경기력을결정한다고알려져있다 [1]. 이연구에서 8주간의복합훈련을통해배구선수의등속성근력의변화를확인하였으며, 그결과복합훈련후발목및무릎관절의근력이유의하게증가하는것으로나타났다. Noh[25] 는남자대학생배 10 The Asian Journal of Kinesiology
구선수를대상으로 6주간의복합훈련의결과, 무릎관절의최대근력이증가하였다고보고하였고, Luebbers et al. [26] 은플라이오메트릭훈련을통해발목과무릎관절및최대수직점프의수행능력에효과가있다고보고하였다. 서론에서언급한것처럼, 플라이오메트릭훈련은근육의신전-반사를이용하며주로점프수행력의증가와근력및근파워를향상시키는데사용된다고알려져있다 [27]. 따라서이연구에서발목과무릎관절의등속성근력이증가한것은플라이오메트릭훈련프로그램의구성중신전-반사형태의점프운동을수행하는동안다리의근력과파워가증가된결과라고생각된다. 통상, 배구선수의허리근력은다양한동작과연결되어있으며, 특히공중에띄워진볼을처리할때던지는팔앞쪽으로허리회전과과다폄동작을하게되고, 이때허리의근력이부족하면동작전개에필요한움직임이적어지게된다고보고하였다 [28]. 선행연구에의하면, 몸통균형훈련은복부와허리관절의근력강화와유연성의효과를얻을수있으며, 몸통의안정화를위한운동프로그램으로주로사용된다고보고하였다 [11]. Lima et al. [29] 은스위스볼을이용한 5주간의몸통균형훈련이허리관절의근력과신체균형능력을증가시켜서몸통안정성에긍정적인영향을미쳤다고보고하였고, Han et al. [11] 은남자고등학생배구선수들을대상으로 12주간몸통균형훈련을실시한결과, 허리의폄과굽힘의근력이증가하였다고하면서, 몸통균형훈련이허리의최대근력을증가시키는데긍정적인영향을미쳤다고보고하였다. 이연구에서도특히몸통균형훈련이여자프로배구선수의허리관절의등속성근력을향상시켰다는사실을확인하였으며, 이러한근력의증가는복합훈련을통해몸통의안정성이유지되면서허리의폄근과굽힘근의근력향상에기여하였을가능성이있다고생각된다. 특히, 배구의스파이크동작은어깨의가속과감속이이루어지는과정으로어깨관절의안정성과근력이필요하며 [12], Song & Hong[30] 은 8주간의몸통강화훈련의결과, 어깨관절의등속성근력이향상되었다고보고하였으며, Ahn et al. [31] 은야구선수를대상으로 6주간의플라이오메트릭훈련을진행한결과, 어깨관절의내 회전근력이증가하였다고보고하였다. 따라서이연구에서어깨관절의등속성근력이증가한것은메디신볼을이용한던지기동작을통해어깨관절의내회전과외회전을반복하는동안에어깨관절의주변근 육이강화된결과라고생각된다. 결론 이연구에서는복합훈련이여자프로배구선수의등 속성근력에미치는영향을검토한결과, 8 주간의복합 훈련은여자프로배구선수의등속성근력을향상시킨 다는사실을검증하였다. 향후에는복합훈련이여자 프로배구선수의등속성근력뿐만아니라신체적특성 과체력요인을포함하여배구경기력과의상관성을팀 및포지션별로보다상세히검토할필요가있다고생 각된다. References 1. Marques MC, Tillaar R, Gabbett TJ, et al. Physical fitness qualities of professional volleyball players: determination of positional differences. J Strength Cond Res. 2009; 23(4):1106-1111. 2. Jung HY. Effects of short-term high intensity plyometric training on muscle injury marker and blood oxygencarrying capacity in high school volleyball players. Korean Journal of Sports Science. 2012; 21(3):1151-1161 3. Choi BK, Yoon HK. The effects of weight training and plyometric training on agility and isokinetic muscle strength. Korean Journal of Sports Science. 2013; 22(1):915-922. 4. Pereira, A, Costa AM, Santos P, et al. Training strategy of explosive strength in young female volleyball players. Medicina (Kaunas). 2015; 51(2):126-131. 5. Vassil K, Bazanov B. The effect of plyometric training program on young volleyball players in their usual training period. J Hum Sport Exerc. 2012; 7:35-40. 6. Brill P W, Couzen GS. The core program. 1st ed. New york Bantam Book. 2002, 1-231 7. Cho HC, Park SH, Roh DS. The characteristics of leg muscular strength of different angular velocity in amateur boxing athletes with chronic low back pain. Korean Journal of Sports Science. 2014; 23(3):1267-1277. 8. Sesto ME, Chourasia AO, Block WF, et al. Mechanical 11
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