D: Vježbanje na vibracijskim platformama
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Topic: D: Vježbanje na vibracijskim platformama
Posted By: vibe
Subject: D: Vježbanje na vibracijskim platformama
Date Posted: 09 Veljaca 2012 at 22:56
| Zbuniti cete sebe i korisnike,mislim da je prerano za clanak o vibracijama a da ga ne naprave suradnjom malo više ljudi,naime ovo je sve konfuzno a namjera je bila dobra. |
Replies:
Posted By: vibe
Date Posted: 09 Veljaca 2012 at 23:07
| Vecinu profesionalnih strojeva za vibracijski trening pokrecu dva medusobno sinhronizirana elektromotora. Copy iz clanka! Slažem se!!! :-) |
Posted By: vibe
Date Posted: 09 Veljaca 2012 at 23:08
| koliko motora ima powerplate pro5? |
Posted By: vibe
Date Posted: 09 Veljaca 2012 at 23:23
| Da ipak rezimiramo malo: Powerplate je JEDAN OD BOLJIH aparata na tržištu kao mnogo ostalih iz te kategorije..npr: Galileo,Physioplate,Vibrogym,Ultim8,FitVibe itd..ima ih još dosta a ima ih puno previše koji nebi trebali biti u upotrebi.. Poozzz |
Posted By: Asia
Date Posted: 10 Veljaca 2012 at 10:25
| Koliko sam ja upoznata s tim,trenutno najbolji na tržištu je Dream Healther,samo ne znam da li ga uopce ima kod nas. |
Posted By: vibe
Date Posted: 10 Veljaca 2012 at 10:46
| Asia, budi ozbiljna.. Niti na otpad se ne isplati tako nesto nositi! |
Posted By: Asia
Date Posted: 10 Veljaca 2012 at 11:21
|
A cuj i ja sam mislila isto,a onda su mi kao na nos bacili neka testiranja,kao,da jedini ne utjece na vibraciju mozga,
inace nisam uopce pristaša takvog nacina treniranja,ali sam u jednom periodu htjela nešto isprobati, cak i kupiti jedan pa su mi kao rekli,da je to jedino kod cega je najmanje posljedica,a da toga kod nas niti nema. Tako da ne znam više nego to...ali,kao što rekoh ta vrsta treninga mi se ne cini zanimljiva,pa zato nisam išla istraživati dalje od toga.... |
Posted By: vibe
Date Posted: 10 Veljaca 2012 at 11:36
| Da,to je zbog toga što svi pa i mnogi treneri i centri misle da se mora stajati kao ukras na platformi..ne iskorištava se ni najmanje ono što se može..trening može biti itekako zanimljiv... |
Posted By: The Phoenix
Date Posted: 10 Veljaca 2012 at 11:46
|
Meni je smiješno to uopce i nazivati treningom
------------- http://www.nikolasfitnesslab.com/ - http://www.nikolasfitnesslab.com/ |
Posted By: davor23
Date Posted: 10 Veljaca 2012 at 13:06
Probao par minuta.. otpale mi ruke i noge.. prvo ruke jer sam bio u polozaju skleka 1 min, a noge u polozaju cucnja.. ------------- I believe whatever doesn't kill you, simply makes you ... stranger |
The Phoenix wrote:Posted By: The Phoenix
Date Posted: 10 Veljaca 2012 at 13:13
Prvi put si radio to sto je tvom tijelu novi podrazaj, tako da normalno da te boljelo, ali svejedno to ne smatram treningom , niti moze zamijeniti klasicni oblik treninga niti u kojem transformacijskom pogledu..........ne smatras valjda tu 1 minutu da si odradio trening? ------------- http://www.nikolasfitnesslab.com/ - http://www.nikolasfitnesslab.com/ |
Posted By: Zoki
Date Posted: 10 Veljaca 2012 at 13:30
|
Bude vibe objasnio prednosti - slušamo... :) ------------- Fitness oprema i dodaci prehrani na : http://www.fitness.com.hr/shop.aspx - Fitness.com.hr WebShop-u - http://www.fitness.com.hr/shop/dodaci-prehrani/proteini.aspx - Proteini |
Posted By: vibe
Date Posted: 10 Veljaca 2012 at 16:01
| naravno da je smješno uopce nepotrebno stajati 1 minutu u statickom položaju,zakiseliti mišice te završiti sa vježbama za noge..umjesto toga za pocetak možemo probati napraviti aktivni cucanj sa npr. medicinkom 4kg u rukama te se iz cucnja uspraviti,podignuti loptu te podignuti na prste(dodamo listove) i tako npr 20 sec,pa 10 sec odmora pa opet i tako npr. 5 krugova-serija=tabata sistem treninga + još malo iskoritimo platformu...nakon toga idemo dalje...slušam :-) |
Posted By: vibe
Date Posted: 10 Veljaca 2012 at 16:05
| Phoenix cekam te na treningu :-),onda dodamo trx(zakacimo noge)na podakticama stojimo na platformi te se jednom podignemo na dlanove a drugi put privucemo noge i podignemo kukove(noge su zakacene na trx-u),može duža serija , može tabata sistem..itd prilagoditi korisniku.. Phoenix bi mogao npr. dok ja ne porucam pa nastavljamo dalje :-) smisao same platforme ne znaci da se ne korsiti sve iz klasnicnih oblika treninga,dapace klasnicnom obliku treninga se doda podražaj vibracije i ne moramo to raditi za svaku vježbu! |
Posted By: The Phoenix
Date Posted: 10 Veljaca 2012 at 16:40
Ok, pustimo vjezbice na stranu, isto tako mogu zonglirati na madracu od kreveta ili na kutiji s jajima da ju ne zdrobim, mene zanima kakve koristi ja imam od toga? Snagu necu povecat i razvit, hipertrofiju neku vrijednu spomena necu dobit zonglirajuci sa tim rekviziticma, fat loss ako skakucem i radim neke tabata/intervalne metode moze, ali to mogu i bez platforme i nisam ogranicem malim prostorom za kretanje, nacinom izvodjenja vjezbi i opterecenjem, sta onda imam od toga ako cu eventualno malo "istonirati" tijelo i skinuti nesto sala? Moj stav o tome je da je to prvenstveno marketing i daleko preskupa stvar koja ne opravdava tolik novac i vise je stvar da bude fancy i definitivno cilja na zensku populaciju (vibracijska podloga ne  ).Ali ako neko to voli i zabavno mu je zasto ne, ali da se smoze svrstati u kos sa klasicnim vjezbanjem , pa cak ga i nadmasiti je po meni nebuloza..........bez uvrede :)Moze se sigurno korisno iskoristiti samo kao jos jedan od "rekvizita" koje koristimo u vjezbanju i za neke odredjene funkcije gdje moze biti koristan , ali nista vise od toga............... samo iznosim svoj stav------------- http://www.nikolasfitnesslab.com/ - http://www.nikolasfitnesslab.com/ |
Posted By: The Phoenix
Date Posted: 10 Veljaca 2012 at 16:58
Ako je zabavan i zanimljiv ne moze biti ucinkovit , kao sto rekoh namjenjem zenskoj populaciji ------------- http://www.nikolasfitnesslab.com/ - http://www.nikolasfitnesslab.com/ |
Posted By: vibe
Date Posted: 10 Veljaca 2012 at 17:42
| Milsim da ipak griješiš, no svatko ima pravo na svoje mišljenje naravno. Ne mjenja jedna sprava neki sistem treninga nego samo oplemenjuje odredenu vrstu treninga..isto tako neznam zašto nebi moglo biti nešto ucinkovito i zabavno...to je ipak stvar glave nakraju,ako ti je muka od tvog treninga ne znaci da je korsitan, a ne vidim zbog cega bi nešto bilo za žene ili muškarce...možda nema žena u prostoru u kojem trniraš pa misliš da radiš trening za muškarce ili? Zacudio bi se što sve "žene" mogu pa ti i prijateljski savjetujem da i ponekad otreniraš u mješovitoj skupini. vidim kuda ovo sve vodi jer si i tabatu popljuvao(jedan od najucinkovitjih sistema za eksplozivnost i snagu(japanski klizaci) No da se ne prepucavamo više,bitno je da mi svi nešto trenkamo,neki sami pred ogledalom neki medu populacijom žena i miuškaraca :-) Jao si ga tebi kad se žene obruše na tebe sada :-) Uglavnom,žao mi je da se nemožemo oko nicega složiti :-( Svaka aktivnost bolja je od nikakve a pogotovo ako je motivirajuca i zabavna na kraju krajeva, ne trebaju svi izgledati kao glumci sa platna,dovoljno je da smo sretni zadovoljni i uzivamo u društvu nježnijeg spola. lp |
Posted By: The Phoenix
Date Posted: 10 Veljaca 2012 at 22:21
|
Zato i postavljam pitanje da cujem odgovore po tom pitanju pa da vidim kontrargumente.......dakle hipertrofija, snaga? Znam da moze biti od koristi kod povecanja explozivnosti za sportase , ali samo kao pomocni tool, dok je ovgdje gdje sam naveo nebitan i neiskoristiv Krivo si me shvatio za tabatu,nisam pljuvao po njoj nego rekao da ju mogu raditi i bez power platea i ostale oblike treneinga bolje jer nisam ogranicen prostorom, opterecenjem i vjezbama.. A ucinkovit trening i zabava......pa nejdu bas zajedno, zabavan je ples, zumba, grupni programici i sl, evo mozemo onda dodati i power plate treninge, a klijentela za takav oblik treninga asu 99% žene, a one ukoliko se bavis trenerskim poslom onda jako dobro znas da su pune predrasuda i strahova oko treninga i da ne postanu bilderice pa se u vecini slucajeva odlucuju na nesto takvoga.Slazem se da je i bolje da se zabavljaju pa rade bilo kakvu aktivnost nego da radi straha, dosade, nedostatka upornosti ili bilo cega odustanu pa se ne bave nicim.A i ako odredjena skupina ljudi nesto trazi treba im to i prodati, ipak je fitness ogromna lova i industrija, manje je bitno kaj je dobro, bitnije je kaj se trazi danas i kaj je putem marketinga nametnuto. Inace treniram u teretani sa 200 ljudi oko sebe i vise , tak da nemam problema sa time,ne dolazim u teretanu radi zabave i drustva ljepseg spola, za to postoje druga mjesta, a ako sam vec odvojio vrijeme za trening onda ga zelim odraditi da izvucem maksimum iz njega. Da ne ispadne da sam zatvoren za druge oblike vjezbanja radio sam i aerobic u mjesovitoj grupi i na to gledam kao upravo to, razbijanje rutine, malo zabave, extra cardio work neopterecujuci, ali kao nesto ucinkovito ne, jer previse izgubljenog vremena za minimalne rezultate koji me nebi nikad zadovoljili. Inace, ne smatram ovo prepirkom,zapravo svidja mi se nacin na koji pises bez da se osjecas napadnutim ako cujes kontrargument, sto cesto nije slucaj .........Ja sam samo komentirao clanak koji je senzacionalisticki i tek tak da se nekaj pise , tak da zapravo nema veze s tobom.........osim akoi ti tvrdis da je to revolucionarno i ucinkovitije od klasicnog treninga :) ------------- http://www.nikolasfitnesslab.com/ - http://www.nikolasfitnesslab.com/ |
Posted By: Iluvatar
Date Posted: 11 Veljaca 2012 at 11:51
|
Vibe, ako je po tebi tabata za eksplozivnost i snagu onda mislim da trebaš još malo prouciti teoriju treninga jer ovako gubiš kredibilitet i na ostalim tvrdnjama.
Isto tako znam da vrhunski svjetski treneri tvrde da nema nekog pretjeranog smisla forsirati vibracijski trening, a i daleko je preskupa stvarcica ( i ona sama i treninzi na njoj) za ono što MOŽDA ( nisam mogao staviti vece možda na žalost) nudi.
Opceniti zakljucak je ovaj: možda si ti i uvjeren da vibro plate radi sve to što piše tu, ali meni je to i dalje samo uzimanje prevelikih novaca ljudima pod krinkom zabavnog treninga, uživanja u nježnijem spolu, bolje išta nego ništa fori i tako dalje...
Ono što je bitno je da nikad nije kasno za promjenu ;) ------------- Muscle mass does not always equal strength. Strength is kindness and sensitivity. Strength is understanding that your power is both physical and emotional. O osobnim treninzima kontakt na pm. |
Posted By: Mr G.
Date Posted: 11 Veljaca 2012 at 12:10
|
Osobno sam mišljenja da je vibracijski trening jedna velika prodaja magle i da uopce nije potreban. ------------- |
Posted By: vibe
Date Posted: 11 Veljaca 2012 at 13:46
| Nisam ja niti podupro clanaka nego suprotno,u clanku stoji niz nistina oko samih vibracija,slijedece nikako nisam rekao da sama sprava zamjenjuje išta nego da se odlicno uklapa kao još jedno sredstvo za rad..može se korsititi za cjeloviti trening,za odredene vrste potreba,može se korititi kao dodatak itd. Osobno imam puno dobrih iskustava,što osobno što radeci sa ljudima..sada vec više od 3 godine i preko 400 klijenta.. Da se razumijemo ne radim samo to nego cjelovite funkcionalne treninge koristeci i samu vibracijsku platformu pa i cjelovite vibracijske programe prilagiodene pojedinom korisniku..iskreno nikad nisam vidio tako brzi napredak u rekreaciji kao što se pokazalo koristeci vibracijsku platformu..mnogo podražaja na proprioceptivni sustav,poboljšanje ravnoteže,jacanje dubokih mišica oko kicmenog stupa,stabilizacije trupa i koljena itd...mnogo je primjera i to na velik broj ispitanika..tako da neznam što bih vam rekao više...no dosta duboko smo otišli s time da skoro ne radimo ništa slicno što je do danas plasirano u medijima vezano za vibr.plat. Drugo sprava košta kao jedan bolji orbitrek cca 35000kn dakle ne razgovaramo o ciframa kao neki drugi proizvodaci a sprave prolaze test usješno preko 3 godine..sami smo ih uzeli nakon osobnih testiranja raznih modela... konkretno radi se o proizvodacu iz Velike Britanije,ultim8 model pro,robusni su ,cvrsti,izdržljivi,dva motora itd.. Dakle ne treba raditi ništa spektalurano oko toga,to je jednostavno samo još jedan rekvizit za rad i meni osobno se pokazao vrlo koristan ali uz mnogo truda mene i mojih djelatnika jer mislim da smo izvukli maksimum iz toga što i kako se može raditi s time.. Pritom ne kažem niti tvrdim da je za nekoga bolje nešto drugo ili suprotno,samo argumentiram da postoji trenutno zbilja mnofo ljudi kojima smo i pomogli na ovaj nacin i osjecaju se jako dobro.. Žao mi je što su vibracijki trening izbanalizirali poceviši od reklama itd..ocito su imali ciljanu populaciju i u tome donekle uspjeli ali mi ne radimo tako te smo razvili svoj vlasiti sustav...ne radimo u velikoj sredini a radimo vec dugo i kvalitetno sa stalnim polaznicima pa valjda mogu pretpostaviti da promjene i rezultati jesu dobri s obzirom na sve navedeno.. Osim toga naravno radimo i druge stvari i vrlo smo otvoreni za sve...sve ovo mi pocinje nalikovati kao da raspravljamo koja je borilacka vještina "najjaca" dali bi netko iz shaolin samostana razbio brok lesnara ili bruce lee nekog ninju...jednostavno sve ima neku svoju svrhu. lp |
Posted By: vibe
Date Posted: 11 Veljaca 2012 at 15:45
| WBV_knee_angle_July_7_NSCA EFFECT OF KNEE FLEXION ANGLE ON NEUROMUSCULAR RESPONSES TO WHOLE-BODY VIBRATION Short duration exposure to Whole-Body Vibration (WBV) during standing elicits acute increases in power and force of leg extensor muscles, possibly due to spindle modulated reflex contractions. A related research study in our laboratory demonstrated increased leg muscle EMGrms during two different modes of WBV. Changes in muscle length and damping characteristics of the body during varying degrees of knee flexion may affect neuromuscular responses to WBV. PURPOSE: To determine whether changes in knee flexion angle (KA) and vibration modality (M) affect neuromuscular responses of leg muscles during short periods of WBV. METHODS: Surface EMG was recorded from the tibialis anterior (TA), gastrocnemius (GS), biceps femoris (BF), and vastus lateralis (VL) of the right leg of ten male and six female subjects. Two different modalities of vibration were used: vertical vibration (VV) and rotational vibration (RV) using two separate platforms. Both platforms vibrated at 30Hz with 4mm amplitude at subjects’ feet. During WBV, subjects performed dynamic squats from 10o to 40o (0o=upright), each lasting 10 seconds. KA was recorded at 400Hz using a motion capture system. Baseline trials were performed prior to every WBV trial, all conditions were performed twice, and the order in which platforms were used was balanced over the 16 subjects. A bandstop filter removed motion artifact and line interference from EMG data between 25-35Hz and 55-65Hz, respectively. Root mean square EMG (EMGrms) was calculated over each 5o of knee flexion for each trial. For each muscle, interactions between WBV, M, and KA were compared using Repeated Measures ANOVA. Significant WBV x M x KA interactions were followed-up by separate WBV x KA ANOVAs for each modality. RESULTS: During VV but not RV, significant (p |
Posted By: vibe
Date Posted: 11 Veljaca 2012 at 15:46
| NEW TRENDS IN TRAINING SCIENCE: THE USE OF VIBRATIONS FOR ENHANCING PERFORMANCE by Carmelo Bosco, Marco Cardinale, Olga Tsarpela and Elio Locatelli Introduction The adaptive responses of the human body to training stimuli have been investigated in depth over the past few years. Thanks to the research carried out in different parts of the world, we know that the adaptation to the training stimulus is related to the modification induced by the repetition of daily exercises, which are specific to the movements executed (Edington and Edgerton, 1976). These adaptations are related to the fact that human skeletal muscle is a specialised tissue, which modifies its overall functional capacity in response to regular exercise with high loads (McDonagh and Davies, 1984). The above-mentioned findings all suggest that resistance exercise can be an effective means of enhancing muscular performance. In this context it should be noted that changes within the muscle itself constitute the most important adaptation to resistance exercise (Sale, 1988; Behm, 1995). In fact, strength training responses have been shown to be mediated by both neurogenic and myogenic factors (Moritani and De Vries, 1979). Neural adaptations have been shown to be the first changes to occur in the muscle, permitting gains in muscle strength and power in the early stages of a resistance exercise programme in the absence of an increase in the cross-sectional area of the muscle (Behm, 1995; Costill et al. 1979). It has also been demonstrated that specific adaptations occur depending on the training programme implemented (Sale and McDougall, 1981). Strength training can therefore be considered as a training stimulus, which produces specific adaptations in human skeletal muscles, based upon the protocol, utilised for training. The specificity of training effect from strength work has been underlined by many authors (Sale, 1988; Behm, 1995; Morrisey et al. 1995; Bandy et al. 1990) and the velocity specific effect has been highlighted as the most interesting outcome of resistance exercise programmes. However, even if the mechanisms underlining this velocity specific effect have not been clearly defined, most importance has been given to the neural adaptations such as improved co- ordination, increased activation of the prime mover muscles (Moritani and De Vries, 1979), recruitment and synchronisation. The aim of most resistance training programmes for elite athletes is to improve the mechanical power output for a given movement, or to enhance speed. In thinking about a boxing punch, a handball throw, a volleyball spike, or a shot putt, these movements involve the exact timing of many muscle groups and are characterised by many coordinative factors. However, boxers, handball and volleyball players and shot putters undergo strength training sessions with the aim of improving their level of performance. Any ideas injected into the deve1opment of a training plan for such sporting disciplines must therefore be related to the specificity of each of the movement patterns involved. An optimal training plan should be developed with some general exercises to improve muscle strength and some specific exercises to improve muscle power and speed. The mechanical basis of strength training is thus very simple: overload the biological system in order to determine specific adaptations. Since the environment of our biological sys- tem is characterised by the fact that we are all subject to the action of gravity which pro- vides the major portion of the mechanical stimulus responsible for muscle structure in everyday life and training, we need to alter the biological system by increasing the gravitational load in order to enhance strength. It should be remembered that specific programmes for strength and explosive power training employ exercises performed with fast, abrupt variations of gravitational acceleration (Bosco, 1992). To give an example, the simulation of hypergravity (wearing vests with extra Ioads) has been utilised for improving explosive muscle power (Bosco et al. 1984; Bosco 1985). The overload or simulation of hyper- gravity are not the only means for changing the gravitational conditions. In fact, mechanical vibrations applied to the body can produce changes in the gravitational conditions and determine specific responses. The studies conducted from our group were aimed to investigate the effects of vibrations applied to the whole body or to part of it in terms of hormonal responses, explosive power, neuromuscular performance and strength. This article aims to present the latest findings on vibrations and some considerations for their use in the athletic setting. The effects of vibrations on human performance The first study carried out by our group was conducted to study the effects of whole body vibrations on the mechanical power of the lower limbs. For this aim, fourteen active subjects involved in team sports training voluntarily participated in the experiment. After being randomly assigned to either an experimental or a control group, they were tested on an Ergojump (MAGICA, Rome, Italy) for assessing vertical jumping ability. The treatment group underwent whole body vibrations at a frequency of 26 Hz (displacement = 10mm, acceleration = 54 mos-1 ) for 5 repetitions lasting 90 sec. each and separated by an interval of 40 sec.. This procedure was continued for 10 days, the duration of vibration series being extended by 5 sec. every consecutive day up to a total of 2 min. per set. At the end of the 10-day period the subjects were re-tested. The results showed remarkable and significant (p |
Posted By: vibe
Date Posted: 11 Veljaca 2012 at 15:47
| WBV_modality_NSCA_July7 NEUROMUSCULAR RESPONSES TO TWO WHOLE-BODY VIBRATION MODALITIES DURING DYNAMIC SQUATS INTRODUCTION: Whole Body Vibration (WBV) is a method used to stimulate skeletal muscle reflexes and has been shown to elicit training responses in muscle strength and power. PURPOSE: The purpose of this study was to determine the acute neuromuscular response of the vastus lateralis (VL), biceps femoris (BF), gastrocnemius (GS), and tibialis anterior (TA) during two different modalities of WBV compared to baseline. METHODS: Ten males and six females performed squats with a stance width of 21.6cm from 10o–40o of knee flexion. Subjects squatted at a cadence of 4s down and 4s seconds up without vibration (BL) and on two different WBV platforms. The first platform (VV) vibrated vertically with 4mm of vertical displacement at 30Hz. The second platform (RV) rotated about an axis with a vertical displacement of 4mm at 30Hz. The order of WBV modes was balanced, and a BL squat was performed immediately before each WBV trial. Simultaneously with knee angles (optoelectronic motion capture), surface EMG data were collected from the right VL, BF, GS, and TA during the squats. The data were filtered using band stop filters at 25-35Hz and 55-65Hz to remove artifact associated with vibration and line interference, and the root mean square of the filtered data were calculated using a 100 ms time constant over each trial. A 2 x 2 Repeated Measures (RM) MANOVA followed by RM univariate ANOVAS and t-tests (Sidak adjustment) to evaluate main effects of vibration (VB), and modality (M) and their interactions for each muscle. RESULTS: These data show a significant (p |
Posted By: vibe
Date Posted: 11 Veljaca 2012 at 15:47
| Effects of whole body vibration training on postural control in older individuals: A 1 year randomized controlled trial An Bogaerts a, Sabine Verschueren a,*, Christophe Delecluse b, Albrecht L. Claessens b, Steven Boonen c a Division of Musculoskeletal Rehabilitation, Department of Rehabilitation Sciences, Faculty of Kinesiology and Rehabilitation Sciences, Katholieke Universiteit Leuven, Tervuursevest 101, 3001 Leuven, Belgium b Research Center for Exercise and Health, Department of Biomedical Kinesiology, Faculty of Kinesiology and Rehabilitation Sciences, Katholieke Universiteit, Leuven, Belgium c Leuven University Center for Metabolic Bone Diseases and Division of Geriatric Medicine, Faculty of Medicine, Katholieke Universiteit, Leuven, Belgium Received 6 June 2006; received in revised form 12 September 2006; accepted 26 September 2006 Abstract This randomized controlled trial investigated the effects of a 12 month whole body vibration training program on postural control in healthy older adults. Two hundred and twenty people were randomly assigned to a whole body vibration group (n = 94), a fitness group (n = 60) or a control group (n = 66). The whole body vibration and fitness groups trained three times a week for 1 year. The vibration group performed exercises on a vibration platform and the fitness group performed cardiovascular, strength, balance and stretching exercises. Balance was measured using dynamic computerized posturography at baseline and after 6 and 12 months. Whole body vibration training was associated with reduced falls frequency on a moving platform when vision was disturbed and improvements in the response to toes down rotations at the ankle induced by the moving platform. The fitness group showed reduced falls frequency on the moving surface when vision was disturbed. Thus, whole body vibration training may improve some aspects of postural control in community dwelling older individuals. # 2006 Elsevier B.V. All rights reserved. Keywords: Whole body vibration; Postural control; Fitness training; Older individuals 1. Introduction Falls are a major problem in older individuals and around 30% of the community dwelling population over 65 falls each year [1]. This can result in functional impairment, serious injuries, fractures or even death. Poor balance is one of the few risk factors for falls that can improve with intervention. Advancing age is associated with impaired postural stability due to deficits in sensory function, central processing, neural pathways for motor control and musculoskeletal integrity [2]. Several studies have shown that training can improve balance in older persons. Most of these have included multidimensional exercise interventions directed towards strength, flexibility and aerobic capacity [3,4]. Visual feedback training [5], aerobic dancing [6] and exercise balls [7] can also enhance postural control. Some studies focusing on strength training alone did not show any positive effect on balance [8,9] and one trial [10] reported deterioration after 12 weeks of low volume strength training. In contrast, another provided evidence for improved postural sway in elderly after 18 months of strength training [11]. Whole body vibration (WBV) training might potentially be useful to enhance balance. The subject performs exercises on a platform that generates vertical sinusoidal vibrations. www.elsevier.com/locate/gaitpost Gait & Posture 26 (2007) 309–316 * Corresponding author. Tel.: +32 16 32 90 70; fax: +32 16 32 91 97. E-mail address: [email protected] (S. Verschueren). 0966-6362/$ – see front matter # 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.gaitpost.2006.09.078 |
Posted By: vibe
Date Posted: 11 Veljaca 2012 at 15:51
| 13 Abstract of the Ph.D. Thesis The effects of vibration on human performance and hormonal profile By Marco Cardinale Semmelweis University Doctoral School Faculty of Physical Education and Sport Sciences Doctoral Program: Empirical and theoretical issues in sport sciences Program Director: Prof. Dr. Frenkl Rňbert Supervisor: Prof. Dr. Carmelo Bosco Budapest 2002 14 INTRODUCTION Skeletal muscle is a specialised tissue, which modifies its overall function capacity in response to chronic exercise with high loads (e.g. Mc Donagh and Davies 1984). The adaptation to the training stimulus is related to the modification induced by the repetition of the daily exercise, which are specific for the movement executed (Edington and Edgerton , 1976). Strength training response has been shown to be mediated by both neurogenic and myogenic factors (e.g. Moritani and De Vries, 1979). Intensive prolonged strength training is known to induce a specific neuromuscular (e.g. Sale, 1988) and hormonal (e.g. Guezennec et al ,1986 ) adaptive responses in the human body in few months ,while the changes in the morphological structure occur later ( e.g. Sale,1988). However, the exact mechanism which regulate how the body adapts to the specific demands upon it , is still unknown. In addition , even less knowledge are available in respect to fatigue, relative strength loss and hormonal changes during one acute session exercises ( e.g. Hakkinen and Pakarinen 1995). It should be remind, that strength and explosive power training specific programs are based on exercises performed with rapid and violent variation of the gravitational acceleration (Bosco, 1992). Gravity normally provides the major portion of the mechanical stimulus responsible for the development of the muscle structure during everyday life and during training. In this connection, simulation of hypergravity (wearing vests with extra loads) conditions has been utilised for enhancement of human explosive muscle power (Bosco et al., 1984; Bosco 1985). On the other hand, changes of the gravitational conditions can be produced also by mechanical vibrations applied to the whole body. In light of the above observations, it can be assumed that application of whole body vibration and/or locally applied vibrations to physical active subjects could influence the mechanical behaviour of lower and upper limbs’ muscles. Vibrations have been extensively studied in occupational medicine and ergonomics. It means that they represent some sort of stimulus to which all of us undergo in daily activities. Literature on vibration is mostly related to the study of vibrations as a diagnostic tool and on their effect on chronical exposure. In fact, most of the work has been carried out in occupational medicine and ergonomics and in animal experiments to be able to understand what is the effect of vibrations on human body. However, even if there is a respectable amount of scientific work on the topic, it is difficult to come to a consensus since different devices have been used and different vibration treatments have been utilised (changing frequency, acceleration and displacement). Moreover, the application of vibrations as an exercise tool is a rather new topic in literature (i.e. Issurin 1994, Issurin et al., 1999). Based upon the literature findings it is possible to affirm that vibrations provide a strong stimulus for the neuromuscular system, the bone and the muscle tissue itself. Not only that, hormonal responses 15 have been identified in human and animal experiments following vibrations treatments (i.e. McCall et al., 2000; Dmitriev & Tropnikova, 1988). The aim of this work was to study the effects of vibrations on human performance and hormonal profile and to provide further information for applying vibration exercise in the athletic setting. Research Hypotheses The problem addressed in this series of studies was the effect of vibrations on human performance and hormonal profile. Based upon the literature findings, the following research hypotheses were generated: 1) Prolonged administration of vibration treatments produce enhancement of neuromuscular performance similar to the improvements obtained following explosive jumping training and resistance exercise 2) Acute effects of vibrations treatment modifications of neuromuscular performance and hormonal profile similar to the ones observed following resistance exercise or explosive jumping training 3) Vibration treatment lead to an improvement of neuromuscular efficiency. METHODS A total of sixtytwo subjects voluntarily participated to the studies. They were all physically active and involved in regular exercise. Their characteristics are presented in the following table: Study Number Gender Age (years) + SD Height (cm) + SD Weight (kg) + SD 1 14 ? 20.2 + 0.9 179.5 + 10.1 72.8 + 5.9 2 6 ? 19.5 + 2.1 174.9 + 3.2 65.1 + 3.7 3 12 ? 20.1 + 3.1 173.7 + 7.2 69.6 + 21.4 4 14 ? 25.1 + 4.6 177.4 + 12.3 80.9 + 12.9 5 8 ? 30.7 + 5.3 188 + 4.7 89.3 + 7.2 6 8 ? 21.8 + 2.2 180.1 + 6.4 81.4 + 21.5 Anthropometric measures (height and weight) were recorded together with the age of the subjects at the beginning of each study. 16 Vertical Jumping. The followings jumping tests were performed: counter movement jump (CMJ) and 5s of continuous jumping (5s CJ).The flight time (tf) and contact time (tc) of each single jump were recorded on a resistive (capacitative) platform (Bosco et al., 1983) connected to a digital timer (accuracy ± 0.001s) (Ergojump, Psion XP, MA.GI.CA.Rome, Italy). To avoid un-measurable work, horizontal and lateral displacements were minimised, and the hands were kept on the hips through the test. During CMJ the knee angular displacement was standardised that the subjects were required to bend their knee approximately 90°. The rise of the centre of gravity above the ground (h in meters) were measured from flight time (tf in seconds) applying ballistic laws: h = tf2 • g • 8-1 ( m ) [1] where g is the acceleration of gravity (9.81 m•s-2). During CJ exercises the subject were required to perform the maximal jumping effort minimising knee angular displacement during contact. From the recordings of tf and tc the average mechanical power (AP), average rise of center of gravity (AH) were calculated for the total 5s continuos jumping. From 5s CJ the best jumping performance was selected and maximal mechanical power (PBJ) as well as the highest rise of center of gravity (HBJ) were obtained using the equation introduced by Bosco et al. (1983) : AP = Tf • T • 24.06 • ( Tc )-1 (W • kg bm-1) [2] where P is the mechanical power per kilogram of body mass, Tf the sum of the total flight time, Tt the total working time (5s), and Tc the sum of the total contact time. The average height during 5s CJ and the HBJ were computed using formula [1]. The reproducibility of the mechanical power test (5s CJ) and CMJ performances were high with respectively r=.95 and r =.90 (Bosco et al., 1983; Viitasalo & Bosco, 1982). Iso-inertial dynamometry was implemented in study 2,3,4,5 and 6. During the test, the vertical displacements of the loads were monitored with simple mechanics and sensor arrangement (Muscle Lab®, Ergotest Technology A.S., Langensund, Norway). The loads were mechanically linked to an encoder interfaced to an electronic microprocessor (Muscle Lab, Pat. No.1241671). When the loads were moved by the subjects a signal was transmitted by the sensor every 3mm of displacement. Thus it was possible to calculate average velocity (AV), acceleration, average force (AF), and average power (AP), corresponding to the load displacements (for details see Bosco et al., 1995). The dynamic exercises reproducibility testing gave a test-retest correlation r = 0.95 for the average power (P) (Bosco et al., 1995). Electromyography. EMG analyses were performed with bipolar surface electrodes (interelectrode distance 1.2 cm) including an amplifier (gain 600, input impedance 2Giga , CMMR 100dB, bandpass filter 6-1500 Hz; Biochip Grenoble, France) fixed longitudinally over the muscle belly. The MuscleLab converted the amplified EMG raw signal to an average root-mean-square (rms) signal 17 via its built in hardware circuit network (Frequency response 450kHz, averaging constant 100ms, total error ± 0.5%). The EMGrms was expressed in function of the time (millivolts or microvolts). Since the EMGrms signals were used in relation with bio-mechanical parameters measured with MucleLab, they were simultaneously sampled at 100Hz. The subjects wore a skin suit to prevent the cables from swinging and from causing movement artefact. A personal computer (PC 486 DX- 33MHz) was used to collect and store the data. Hormonal measurement. The first blood samples were drawn at 08:00 a.m from an antecubital vein after 12 hours fasting and 1 days resting. The second blood sample was obtained right after the end of the vibration treatment. The subjects were asked to sit near to the vibration machine, where an appropriate setup was prepared for blood collection. The blood samples were drawn in the 1-min following the end of the vibration treatment. Serum samples to be used for hormone determinations were kept frozen at –20°C until assayed. The assay for serum total T and cortisol ( C) were performed by radioimmunoassay (RIA) using reagent kits (Diagnostic Products Corporation, Los Angeles California, USA). Growth hormone was measured using RIA reagent kits obtained from radium (Pomezia, Italy). All samples from the tested subjects were analysed using RIA counter (COBRA 5005, Packard Instruments, Meriden, USA). The intra-assay coefficients of variations for duplicate samples were 3.63% for T, 5.1% for C and 2.1% for GH. Blood lactate measurement. Peak lactate concentration was determined from the subject’s ear lobe blood samples before test-1, and 3-5-7 min after 30r-N and 30r-V. The tests were de-proitenezed in ice -cold percloric acid for subsequent analysis of lactic acid (Enzymatic method, Biochimica, Boehring, Mannheim, Germany). Statistical methods. Ordinary statistical methods were employed, including the calculations of means and standard deviation. The Pearson product moment correlation coefficient (r ) was used for test re-test measurement reliability and for correlational analyses. The SD and CV of test re-test measurement were calculated using the following equation (Thorstensson 1976) 1 1 2 ) ( ) 2 CV = (200x SD x x + x - [3] where x1 and x2 are the mean average values of two successive measurements , and SD is the standard deviation of the mean differences between test re-test measurements. Differences between the mean values before and after the vibration treatment were tested for significance using Student’s t-test for paired observations. Repeated measures ANOVA was also used in study 6. For all the studies, alpha was set at p |
Posted By: vibe
Date Posted: 11 Veljaca 2012 at 15:53
| Postoje dokazi kako su skupine vježbaca poboljšale snagu,eksplozivnost,kosti itd u odnosu na drugu skupinu koja je radila iste stvari ali bez platforme.. islim da je vrijeme da završimo temu :-) i nadjemo se na nekoj drugoj :-) |
Posted By: vibe
Date Posted: 11 Veljaca 2012 at 15:55
| Strength Increase after Whole-Body Vibration Compared with Resistance Training CHRISTOPHE DELECLUSE1, MACHTELD ROELANTS1, and SABINE VERSCHUEREN2 1Exercise Physiology and Biomechanics Laboratory, and 2Laboratory of Motor Control, Faculty of Physical Education and Physiotherapy, Department of Kinesiology, Katholieke Universiteit Leuven, Leuven, BELGIUM ABSTRACT DELECLUSE, C., M. ROELANTS, and S. VERSCHUEREN. Strength Increase after Whole-Body Vibration Compared with Resistance Training. Med. Sci. Sports Exerc., Vol. 35, No. 6, pp. 1033–1041, 2003. Purpose: The aim of this study was to investigate and to compare the effect of a 12-wk period of whole-body vibration training and resistance training on human knee-extensor strength. Methods: Sixty-seven untrained females (21.4 1.8 yr) participated in the study. The whole-body vibration group (WBV, N 18) and the placebo group (PL, N 19) performed static and dynamic knee-extensor exercises on a vibration platform. The acceleration of the vibration platform was between 2.28 g and 5.09 g, whereas only 0.4 g for the PL condition. Vibration (35–40 Hz) resulted in increased EMG activity, but the EMG signal remained unchanged in the PL condition. The resistance-training group (RES, N 18) trained knee extensors by dynamic leg-press and leg-extension exercises (10–20 RM). All training groups exercised 3 wk1. The control group (CO, N 12) did not participate in any training. Pre- and postisometric, dynamic, and ballistic knee-extensor strength were measured by means of a motor-driven dynamometer. Explosive strength was determined by means of a counter-movement jump. Results: Isometric and dynamic knee-extensor strength increased significantly (P 0.001) in both the WBV group (16.6 10.8%; 9.0 3.2%) and the RES group (14.4 5.3%; 7.0 6.2%), respectively, whereas the PL and CO group showed no significant (P 0.05) increase. Counter-movement jump height enhanced significantly (P 0.001) in the WBV group (7.6 4.3%) only. There was no effect of any of the interventions on maximal speed of movement, as measured by means of ballistic tests. Conclusions: WBV, and the reflexive muscle contraction it provokes, has the potential to induce strength gain in knee extensors of previously untrained females to the same extent as resistance training at moderate intensity. It was clearly shown that strength increases after WBV training are not attributable to a placebo effect. Key Words: MUSCLE STRENGTH, TONIC VIBRATION REFLEX, COUNTER-MOVEMENT JUMP, STRENGTH TRAINING Whole-body vibration (WBV) is a neuromuscular training method that has recently been developed. In WBV training, the subject stands on a platform that generates vertical sinusoidal vibration at a frequency between 35 and 40 Hz. These mechanical stimuli are transmitted to the body where they stimulate in turn sensory receptors, most likely muscle spindles. This leads to the activation of the alpha-motoneurons and initiates muscle contractions comparable to the earlier described “tonic vibration reflex” (6,11,15). Initially, WBV training was used in elite athletes to improve speed-strength performance. More recently, it is becoming tremendously popular in European health and fitness clubs as an alternative training method. However, there is still a lack of scientific support about the benefits of WBV on fitness and health. Bosco et al. (3,5) found an increase in force-velocity, force-power and vertical- jump performance immediately after one WBV session. A placebo controlled study showed that a single bout of WBV transiently improves isometric strength of the knee extensors and vertical-jump performance by 3.2% and 2.5%, respectively (22). These effects were recorded 2 min after the intervention but disappeared in the next 60 min. Some studies analyzed the effect of WBV training on muscle performance over a longer period. Bosco et al. (2) reported the effect of a 10-d training program of a daily series (5 90 s) of vertical sinusoidal vibrations at a frequency of 26 Hz. They found a significant improvement of the height and mechanical power during the 5-s continuous- jumping test. It was suggested that WBV training finally might result in neuromuscular adaptations similar to the effect produced by explosive strength training. However, 10 d of training is too short to determine the long-term effects of WBV. Runge et al. (20) showed gains of 18% in chair-rising time in elderly persons after 12 wk WBV training (27 Hz). Recently, Torvinen et al. (23) reported a significant increase in jump performance (8.5%) and a nonsignificant increase in isometric limb extension strength (2.5%) after a 4-month WBV intervention (25–30 Hz) in young nonathletic adults. As none of these long-term studies were placebo controlled, it is impossible to determine whether the training effect on strength and jump performance resulted from the exercises that were performed on the platform or Address for correspondence: Christophe Delecluse, Ph.D., Faculty of Physical Education and Physiotherapy, Tervuursevest 101, 3001 Leuven, Belgium; E-mail: [email protected]. Submitted for publication October 2002. Accepted for publication January 2003. 0195-9131/03/3506-1033 MEDICINE & SCIENCE IN SPORTS & EXERCISE® Copyright © 2003 by the American College of Sports Medicine DOI: 10.1249/01.MSS.0000069752.96438.B0 1033 from the vibration induced muscle activation. Additionally, there are no studies available to compare the effect of WBV and resistance training on muscle strength. This is the first long-term study to differentiate between the effects resulting from the exercises performed on the platform with vibration and without vibration (placebo) and to compare the effects of WBV training and resistance training by means of weight machines at moderate intensity. Therefore, the changes in isometric, dynamic, ballistic kneeextensor strength, and counter-movement jump (CMJ) height were analyzed in young female adults after a 12-wk training period. As WBV elicits a high degree of muscle activation, it was hypothesized that WBV would result in strength increase in previously untrained persons. These strength increases should be significantly larger than the training effects resulting from an identical exercise program performed in absence of vibration (placebo condition). As the tonic vibration reflex facilitates the activation of high-threshold motor units and the reflex sensitivity (1,18), WBV training may be more efficient to improve ballistic strength and jump performance compared with resistance training at moderate intensity. METHODS Experimental Approach to the Problem A four group prepost design was used in this study to determine whether a 12-wk period of WBV-training (3 times/wk) would result in a considerable increase in kneeextensor strength, and whether WBV training, compared with moderate resistance training, would be more efficient to improve ballistic and explosive strength in previously untrained subjects. The four groups included a WBV group, a resistance-training group, a control group, and a placebo group. This latter group was added to determine whether the expected training effect in the WBV group resulted from the exercises that are performed on the platform or from the vibration induced muscle activity. Isometric strength, dynamic strength, and ballistic strength of the knee extensors were measured in pre- and post-test conditions. Explosive strength was measured by means of a CMJ. Subjects and Study Design A group of 74 young female adults (age 21.5 1.9 yr; body mass 61.6 9.1 kg; height 165.3 10.3 cm) volunteered to participate in the study. None of them were engaged in regular organized physical activities nor in sports or strength training. Reasons for exclusion were pregnancy, acute hernia, and any history of severe musculoskeletal problems. Subjects with a history of diabetes or epilepsy were also excluded from the study. All subjects were informed about the training and test protocol and about the possible risks and benefits of the study. They all gave written informed consent to participate. This study was approved by the University’s Human Ethics Committee according to the declaration of Helsinki. Power analysis revealed that a sample size of 17 subjects in the experimental groups was necessary to achieve a power of 0.80 with 0.05. In anticipation of inevitable dropout, it was decided to select a minimum of 20 subjects in the experimental groups. All subjects were randomly assigned to one of three interventions: the whole-body vibration (WBV, N 20), the placebo vibration (PL, N 21), the resistance training (RES, N 20), or a control group (CO, N 13). All intervention programs consisted of 36 training sessions within a 12-wk period. Training frequency was three times a week with at least 1 d of rest between two sessions. The control group did not participate in any training program. WBV and PL Conditions The subjects of the WBV group and the PL group performed static and dynamic knee-extensor exercises on the vibration platform: squat, deep squat, wide-stance squat, one-legged squat, and lunge. At the moment, there are no scientific-based, long-term WBV-training programs available. Therefore, we developed a 12-wk WBV program with a low training load at the beginning but slowly progressive according to the overload principle. The training volume increased systematically over the 12-wk training period by increasing the duration of one vibration session, the number of series of one exercise, or the number of different exercises. The training intensity was increased by: shortening the rest periods or by increasing the amplitude (2.5–5 mm) and/or the frequency (35–40 Hz) of the vibration (Table 1). The vibration platform (Power Plate®) produced vertical sinusoidal vibrations at a frequency between 35 and 40 Hz. The peak-to-peak amplitude of the vibration was 2.5 mm at low amplitude and 5 mm at high amplitude. The acceleration of the platform as recorded by means of an accelerometer (Monitran, MTN 1800) varied between 2.28 g and 5.09 g (Table 2). In the PL condition, the subjects, standing on the platform, could hear the motor and experienced tingles on their foot soles, but the acceleration of the platform was only 0.4 g (Table 2) with a negligible amplitude. Bipolar surface EMG (Noraxon Myosystem 2000), recorded from m. rectus femoris and from m. gastrocnemius, illustrates the difference between the impact of the WBV condition and the PL condition on muscle activity. Standing in the squat posture on the platform during WBV leads to an TABLE 1. Training volume and training intensity of the WBV program. Start End Volume Total duration of vibration in one session (min) 3 20 Series of one exercise (N) 1 3 Different knee-extensor exercises (N) 2 6 Longest duration of vibration loading without rest (s) 30 60 Intensity Rest period between exercises (s) 60 5 Vibration amplitude (mm) 2.5 5 Vibration frequency (Hz) 35 40 The status of each variable is described at the start and at the end of the 12-wk training period. 1034 Official Journal of the American College of Sports Medicine http://www.acsm-msse.org increase in muscle activity for the m. rectus femoris and the m. gastrocnemius, whereas the PL condition did not (Fig. 1). During all of the vibration-training sessions, the subjects wore the same gymnastic shoes to standardize the damping of the vibration due to the footwear. The subjects were asked to report possible side effects or adverse reactions in their training diary. Every 3 wk, exercise supervisors performed an inquiry into the attitude and the satisfaction of the subjects in both groups. As the WBV group and the PL group exercised in different rooms and at different moments, they could not compare both conditions, and they could not share their training experiences. Exercise specialists closely supervised all training sessions of all intervention groups. Resistance Training The RES group trained in the university fitness center. After a standardized warming-up consisting of 20-min stepping, running, or cycling, they performed a moderate resistance- training program for knee extensors on a leg-press and a leg-extension apparatus (Technogym®). The resistancetraining program was slowly progressive, similar to the WBV program, starting at a low threshold of 20 RM in the first 2 wk. The training load was first increased to 15 RM in the next 3 wk, followed by another 3-wk period at 12 RM. Subjects trained at 10 RM during the last 4 wk. Leg press and leg extension exercises were executed systematically to fatigue failure with the objective to perform the prescribed number of repetitions. The starting load was determined by an exercise specialist at the first training session. During the whole training period, subjects were observed, and they were instructed to increase the resistance systematically in the after set or in the following session if they were able to perform the current workload for two or more repetitions over the prescribed number (14). The subjects performed two sets of repetitions on each apparatus with at least 1 min of rest in between. Tests The contractile properties of the knee extensors were evaluated at the start (pretest) of the study and after 12 wk of training (posttest). All subjects participated in a standardized warm-up and test protocol on a motor-driven dynamometer (REV9000, Technogym®), consisting of isometric tests, dynamic tests, and ballistic tests for the knee extensors. In addition, all subjects performed a vertical CMJ. The subjects were asked to perform all these tests at maximal intensity. During a standardized warm-up, the subjects exercised the different types of contractions to experience all test conditions before testing. Posttests were performed at least 72 h after the last training session to avoid any acute effect of training sessions on test results. Dynamometry. The isometric, dynamic, and ballistic tests were performed unilateral on the right side, in a seated position on a backward inclined (15°) chair. The upper leg, the hips, and the shoulders were stabilized with safety belts. The rotational axis of the dynamometer was aligned with the transverse knee-joint axis and connected to the distal end of the tibia by means of a length-adjustable rigid lever arm. The alignment of the dynamometer was systematically controlled by inspecting the position of the lever arm with respect to anatomical reference points during passive movements. The three-dimensional positions of the rotational axis, the position of the chair, and the length of the lever arm were identical in pre- and post-test condition. Isometric strength (ISO). The subjects performed twice a maximal voluntary isometric contraction of the knee extensors. The knee joint angle was 130°. The isometric contractions lasted 3 s each and were separated by a 2-min rest interval. The highest torque (N·m) was recorded as isometric strength performance. The intraclass correlation coefficient (ICC) for test-retest reliability of isometric strength, recorded in a comparable group of untrained females, was 0.93. Dynamic strength (DYN). The subjects performed a series of four consecutive isokinetic flexion-extension movements against the lever arm of the dynamometer that moved at a velocity of 100°·s1. The knee extension was initiated at a joint angle of 90° and ended at 160°. After each extension, the leg was returned passively to the starting position from which the next contraction was immediately initiated. Maximal dynamic strength was determined as the peak torque (N·m) recorded during these series of knee extensions. The ICC for test-retest reliability of dynamic strength, recorded in a comparable group of untrained females, was 0.98. Ballistic strength (BAL). The subjects performed four ballistic tests for the knee extensors. They were asked to extend the lower leg at the highest possible speed from a knee-joint angle of 90° to an angle of 160°. This exercise was performed once without external resistance on the lever arm (0%), followed by three identical tests with a controlled resistance on the lever arm. Hereby the degree of resistance was individually determined at a percentage of the isometric maximum in the knee angle from where the movement was initiated (90°). The ballistic tests were performed with a resistance of 20%, 40%, and 60% of this isometric maximum. At each test, the maximal velocity of the lever arm (°·s1) was recorded to determine ballistic strength. The ICC for test-retest reliability of the maximal velocity during ballistic tests, recorded in a comparable group of untrained females, varied between 0.87 and 0.96, dependent on the resistance. TABLE 2. Maximal acceleration (g) on the WBV platform at low (2.5 mm) and high (5 mm) peak to peak amplitude and on the PL platform (amplitude negligible). AMP FREQ WBV Platform PL Platform Low 35 Hz 2.28 0.38 40 Hz 2.71 0.37 High 35 Hz 3.91 0.41 40 Hz 5.09 0.40 g is the Earth’s gravitational field or 9.81 ms2. AMP is the vibration amplitude. FREQ is the vibration frequency. STRENGTH INCREASE AFTER WHOLE-BODY VIBRATION Medicine & Science in Sports & Exercise 1035 Explosive strength. A vertical CMJ with hands positioned in the waist was used to assess the lower-limb explosive performance capacity (4) after stretch shortening of the muscles. This test was performed on a contact mat, recording the flight time in milliseconds. The obtained flight time (t) is further used to determine the increase in the center of gravity (h), i.e., h gt2/8, where g 9.81 m·s2. The best of three trials was recorded to determine the test score. The ICC for test-retest reliability of CMJ performance, recorded in a comparable group of untrained females, was 0.99. FIGURE 1—Root means square (RMS) EMG activity (mV) in the m. rectus femoris (top) and in the m. gastrocnemius (bottom) recorded in static half squat position. The preamplified signal (gain 80 dB) was bandpass filtered (15–10,000 Hz) before sampling at 2000 Hz. RMS-EMG activity was calculated of the rectified EMG signal for a period of 10 s prior vibration, during vibration, and after vibration at 35 Hz with a vertical peak to peak amplitude of 5 mm. 1036 Official Journal of the American College of Sports Medicine http://www.acsm-msse.org Statistical Analysis The effect of the different interventions on strength parameters was analyzed by means of ANOVA for repeated measures [4 (group) 2 (time)] (GLM) using the least square method (LS means). After an overall F-value was found to be significant, preplanned contrast analyses were performed to evaluate the significance of effects (prepost, between groups). A Bonferroni correction was used to adjust the P-value in relation to the number of contrasts that were performed. All analyses were executed using the statistical package Statistica, version 6 (Statsoft, Inc.). Significance level was set on P 0.05. RESULTS Training experiences, compliance, and drop-out. In the WBV and PL groups, subjects acquainted very rapidly the exercise protocol. There were no reports of adverse side effects. Most subjects experienced the vibration loading (WBV group) as enjoyable and fatiguing, but they did not consider it as a hard workout. The supervising staff reported no doubts, concerning the training modalities, in the PL group. All of these subjects (PL) felt confident that they were participating in a real WBV program. During the first weeks of the study, seven subjects dropped out: two subjects of each training group (RES, WBV, and PL), respectively, and one subject of the CO group. All of these drop-outs were related to an incompatibility of the test/training program and other commitments (e.g. work, studies, etc.) of the subjects. All remaining subjects of the training groups (WBV, PL, and RES) performed 36 training sessions. Some subjects needed one extra week to complete all sessions, as they missed up to three sessions during the 12-wk period. The characteristics of the 67 subjects that completed all pre and post tests are given in Table 3. No significant differences in age, body mass, and height among all groups were detected at the start of the study (Table 3). Muscle performance. For isometric strength a significant interaction effect (group time) was found [F(3)15.94, P 0.001]. Contrast analysis clarified that isometric knee-extensor torque (Fig. 2) increased significantly (P 0.001) over 12 wk in the RES group (14.4 5.3%) and in the WBV group (16. 6 10.8%) whereas no significant increase was found in the PL- or the CO group. Regarding dynamic strength a significant interaction effect [F(3)7.81, P 0.001] was found. Contrast analysis showed a significant increase (P 0.001) in dynamic strength (Fig. 2) for the RES group (7.0 6.2%) and the WBV group (9.0 3.2%). The PL group and the CO group did not improve in dynamic strength. The ballistic test results (Fig. 3) revealed no significant effect (P 0.05) in unloaded speed of movement (0%) or in speed of movement with standardized resistance (20%, 40%, or 60% of maximal isometric strength). CMJ height showed a significant interaction effect (group time) [F(3) 5.88, P 0.001]. Contrast analysis clarified that jumping height increased significantly (P 0.001) over 12 wk in the WBV group (7.6 4.3%), but remained unchanged in all other groups (Fig. 4). DISCUSSION This is the first placebo-controlled study that compares the effects of 12 wk of WBV training and resistance training on knee-extensor strength and CMJ performance in previously untrained subjects. The results of this study clearly FIGURE 2—Mean and SD before (pre) and after (post) 12 wk in the RES, WBV, PL, and CO groups. Top: maximal isometric knee-extensor torque (ISO). Bottom: maximal dynamic knee-extensor torque (DYN). † refers to a significant interaction (group time) effect at P |
Posted By: Zoki
Date Posted: 11 Veljaca 2012 at 16:32
|
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Posted By: Iluvatar
Date Posted: 11 Veljaca 2012 at 23:21
|
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Posted By: vibe
Date Posted: 11 Veljaca 2012 at 23:24
| Da , istina,ako netko zbilja zanima da ne raspravljamo na razni ..ja mislim..rado cu poslati sve radove u pdf-u na mailove. Pozdrav |
Posted By: The Phoenix
Date Posted: 12 Veljaca 2012 at 09:12
|
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Posted By: vibe
Date Posted: 12 Veljaca 2012 at 12:15
| Nije samo u rehab svrhe,mogu ti poslati radove mjerene na profesionalnim sportašima i to mjereno po segmentima.. Nemoj misliti da bi u toj industriji uložili toliko novaca bez mnogo godina istraživanja i testiranja,samo što se kod nas malo zna o tome.. Nekad je to bilo preskupo i nedostupno,i sada poprilicno košta ali je ipak dostupnije.. Osobno sam radio pripreme sa poznatim našim sportašima(necu navoditi imena) i dobili povecanje snage koje nikako nisu mogli postici redovnim putem. Izmejereno,provjereno istestirano,polucilo rezultate kako u mjerenjima tako i u takmicenju za koju svrhu je i radeno. Pozdrav |
Posted By: The Phoenix
Date Posted: 12 Veljaca 2012 at 23:07
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moze, slobodno posalji ------------- http://www.nikolasfitnesslab.com/ - http://www.nikolasfitnesslab.com/ |
Posted By: Iluvatar
Date Posted: 19 Veljaca 2012 at 14:05
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Može i meni molit cu, uvjek je dobro nešto novo nauciti.
------------- Muscle mass does not always equal strength. Strength is kindness and sensitivity. Strength is understanding that your power is both physical and emotional. O osobnim treninzima kontakt na pm. |