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Thread: The joke of electrotherapy

  1. #11
    Mr. Quixote, it is quite obvious at this point that you are quite naive on this issue. I cannot see the point in even arguing with you over this issue. If I did not believe that FES worked, I would have never have worked for the company that manufactures the "FES bike". I use FES most everyday and have legs that look like those of an able bodied person even though I am paralyzed for the last 23 years from my upper chest down.

    In addition to the benefits of building leg muscle bulk, the fes bike also builds up the cardio vascular system and is good for the knee joints as it keeps them free and moving rather than sitting all day sedentary in a wheelchair. The range of motion it provides is great therapy within itself, it is also good for circulation in the lower extremities.

    FES has never been promoted as a "Cure" for Spinal Cord injury, It is simply a method to stay in shape until the day a cure comes.

    I also take great offense at your accusations against Dr. Young. It is obvious to me and probabley everyone else reading this that you are a very bitter man, for whatever reason. I think it is very unfair of you to try and discount a therapy as useless that has helped out a great number of people. FES is not for everybody, but those that are candidates for using FES (paralyzed with the proper reflex arc necessary) can greatly benefit by it.

  2. #12
    Don, no personal attacks please.

    To repeat what others have said, no one has suggested that FES can cure paralysis. My post addressed the use of FES as a means to increase tone, I made no statement regarding its role in reversing atrophy, two separate issues.

    Here's a summary of a conversation Dr. Young had with Dr. Kern who's work suggests that FES can reverse severely atrophic muscles.

    Dr. Helmut Kern from Wien (Vienna), Austria. He works in the same group as Milan Dimitrijevic. He used huge electrical currents, much much greater than those that are typically used for FES. This was because he found that one must use very intense trains of impulses from the surface of the skin to activate severely atrophic muscles. Please note that this is in humans with cauda equina lesions. He suggests that such stimulation can restore muscle in people as long as 25 years after injury although he did not present much data to support this statement. At the beginning of the symposium, I had asked Professor Giorgio Brunelli and the assembled clinicians whether a denervated muscle could be restored. Most of the people in the audience felt that a denervated muscle (that has undergone such severe atrophy that most of the muscle is connective tissue and fat) cannot be stimulated or restored. Dr. Kern therefore surprised everybody with his findings. On the other hand, I must point out the technical difficulties of the stimulator devices that he was using (he had to build the stimulators themselves). The amount of electrical energy that he used was truly enormous. Normal FES machines usually cannot deliver more thant 50-100 millijoules of electrical energy. Dr. Kern was using as much as 3 joules (30-100 times) more energy for his stimulus protocols, giving trains of stimuli. Many of the electrodes caused skin burns but he said that the electrical stimulation actually thickened the skin. By the way, such high currents would be very painful to people who have any preserved skin sensations and would cause tremendous spasms to people who have spinal cord injury. That is why the studies were done only in patients with peripheral nerve or cauda equina lesions. I discussed the issues with several of the people afterwards, including Reggie Edgarton (UCLA) and Michael Keith (Case Western) and they expressed some reservations about the safety parameters of such high currents. In order to reduce skin burns, the electrodes have cover a large surface area to minimize current density. The problem is that if the gel dries up a bit or the electrode does not get complete contact, it is very easy to get skin burns. I asked Dr. Kern whether he tried direct stimulation of the muscle, using implanted electrodes, which would cause less damage to the skin. However, he says that he tried direct muscle stimulation and found that the high currents can damage the muscles. We talked until 3 am one of the mornings trying to figure out a better way to stimulate the muscles. However, from the evidence that Dr. Kern shows (he had biopsies of the muscles before and after), it is possible to get completely atrophic muscles to regrow and bulk up again. Now that we know it can be done, it is time to work out the methods to do so safely.
    Source

  3. #13
    "Not even NASA, which admits that debilitation of flight crews from disuse is the biggest obstacle to manned exploration in the solar system, will have anything to do with electrotherapy despite the claims of doctors who urge it upon the handicapped for this very purpose, but don't use it on themselves."

    Seems like they and other space agencies are studying its use......

    NASA via SSB
    ESA
    CSA



    Eric Harness,CSCS
    Project Walkâ„¢

    [This message was edited by Snowman on 03-09-04 at 06:59 PM.]

  4. #14
    Don Quixote,
    There you go again, telling me what I "believe". Please stop doing that as you don't know me personally and you continue to put words in my mouth that I've not said. I don't know if you truly misunderstood, or if it's intentional on your part to misunderstand everyone.

    I have an open mind, however, I don't appreciate you attacking anyone on a personal level, or your derogatory comments concerning Dr. McDonald and Dr. Young. When you attack people on a personal level, it does nothing to lend any credibility to you or anything that you say.

    You made a quite a comment concerning my husband's chance of walking again if he uses this "device" for about 8 years. I don't put any stock in empty statements, but like I said, I have an open mind. I'll listen as long as you are respectful, and show common courtesy... otherwise, I'll go away from this topic. It's OK to have a different opinion about things. People are here to try to gain knowledge, share knowledge and to try to help each other. Or that's what I like to think.
    About the FDA...Personally, I don't put a great deal of "faith" in them. They have approved killer drugs in the past, and are highly influenced by the powerful pharmaceutical companies who of course would prefer to push pills instead of cures. But let's not get off the subject. I don't claim to know it all. That's the first indication that someone doesn't know what they should, because they have a closed mind and refuse to "learn". You say I don't understand. Explain...Tell me what it is that you believe about the nervous system, muscles and electrochemistry instead of simply attacking FES which I believe is beneficial and necessary to my husband's health.

  5. #15
    Seneca, I am indebted to you not just for your comments, but for the conversation summary you included. Your comments will allow me to clarify an important point. I might add that I will try and refrain from personal attacks. In your comments you contrast tone with atrophy. Another posting by Mr. Leatherbee, who formerly was in the employ of the company that makes the FES bike and is so much infatuated with the device that he claims to use it 'most everyday', alludes to muscle mass as well. These are all wonderful terms and very subjective, very influenced by the desires of the observer. I prefer instead to consider the transmission electron microscopy that detects loss of muscle mass and disuse atrophy as the loss of cross-sectional area of the type II muscle fiber. FES has no effect on this whatsoever. Period.
    Now let's get to the meat, the reported conversation between Kern and Young. Kern reports using 'huge electrical currents, much greater than those that are typically used for FES.' I say what is important is not the 'hugeness' of the current. You could turn up the power on the FES bike and it would still do nothing. What is important is the type of current, and the way it is delivered. What were Kern's 'intense trains of impulses made of, what made them intense? In an earlier post I said it would be nice to come across a neuroscientist who knew physics, but it seems that the two areas of study are incompatible. Kern measures the electrical energy of his device delivers in joules. Joules are a measure of work, not electrical energy, and, to the extent that joules are used as units of energy, the energy is expressed in calories or heat energy needed to accomplish that work. Kern doesn't know his electricity, but let's look closer now at his other observations. Maybe we can explain them without the obscuring glasses of the neuroscientist. But first I want to contrast denervation with atrophy. In the former case all nerve supply is lost to the muscle, and, using electromyography, we see what is called the reaction of denervation on the oscilloscope. But a severely atrophic muscle looking similarly wasted will not elicit this oscilloscopic activity It has not lost all its nerve supply, merely the protein that fills the membrane covering the type II muscle fiber. At the neuromuscular junction can be found at least 4 and as many as 8 nerve endings, only a few of which synapse with the cells that crank out the type II fiber. Eliminate all these nerve endings and you have denervation. Stop the firing at the ones that activate the type II fiber, and you have disuse atrophy.
    Moving now to Dr. Kern's claims, I want to say that I too believe that muscles long paralyzed can be restored, if they are severely atrophic. And this is done by introducing an electrical field at the synapse of the once-non-firing (during the acute phase) nerve ending in the neuromuscular junction. The cell there is easily overloaded as it would be if one were healthy and pumping iron, but one doesn't need to be healthy or pumping iron for the affect. And the affect is the increased synthesis of the proteins that make up the type II fiber. I don't know what affect this would have on a denervated muscle.
    Consider now Kern's observations. ". Many of the electrodes caused skin burns..." This is why the FDA ruled out the use of electrochemistry by limiting the amount of current passed to the not-so-'huge' one half milliampere for all marketable powered muscle stimulators. Electrical current is measured in amperes or coulombs per second, not joules. I spoke of this skin problem in an earlier posting here. What Dr. Kern didn't notice was that blistering would occur at the anode, while pitting occurred at the cathode. On the website www.galvanism.org you will find an essay from the journal Bioelectrochemistry in which Swedish researchers attribute these affects to excessive alkalinity and acidity at either of the poles, but, being neuroscientists, they mislabel the poles. The authors were investigating the astounding results the Chinese were getting in destroying benign and malignant tumors using direct current. Dr. Kern found that 'high currents' can damage the muscle, but he could not say how or why. To understand this you must understand the role of polarity in electrochemistry, and the application of electrochemistry to the body, ice and fire. Sure, the cathode (ice) can destroy, but its destruction can be severely limited through the use of a corroding cathode. But the anode (fire) can build, for it involves the introduction of electrochemical energy like that made available by mitochondria. One just needs to know how to use it, and the wonderful things claimed by Dr. Kern will become commonplace. "..from the evidence that Dr. Kern shows (he had biopsies of the muscles before and after), it is possible to get completely atrophic muscles to regrow and bulk up again. Now that we know it can be done, it is time to work out the methods to do so safely. " You'll never get this from the FES bike, or a neuroscience still in the 19th century with a thermodynamic approach to electricity.
    Curt, please tell me where the studies are to support the claims you and your former employer make about this expensive device.
    "I also take great offense at your accusations against Dr. Young." I made no accusations in my postings. I merely delineated the areas where Dr. Young is lacking in knowledge, and where he continues to be remiss if he wishes to posture as one concerned about 'cures' and rehabilitation. "It is obvious to me and probabley everyone else reading this that you are a very bitter man, for whatever reason." Not anymore, actually. I find it quite amusing sometimes to consider people like you who heatedly defend the very sciosophy that keeps them in a wheelchair. " I think it is very unfair of you to try and discount a therapy as useless that has helped out a great number of people." While there is little evidence to support this claim, one thing does stand out, your former employer benefits greatly from the sale of these devices that will someday be found in garages and landfills across the country.

  6. #16
    Sen,
    The section you posted/quoted, only suggests that the potential may be there, using FES, but not currently, given "normal FES machines usually cannot deliver more thant 50-100 millijoules of electrical energy", much less than what Dr. Kern used and that any effects were with "enormous" amounts of energy, which have shown to be dangerous and possibly even harmful, from what was stated. This of course doesn't preclude the researches from continuing to develp means that enable positive results/benefits at lower currents for consumer use. One further thing: "He suggests that such stimulation can restore muscle in people as long as 25 years after injury although he did not present much data to support this statement." This always makes me skeptical and concerns are, people often overlook how critical this is, especial;ly coming from scientists who should know better than to make such blanket statements. If they are suggesting that there is a high probablity of restoration of muscles (for ex, but applies to whatever the study is on), then they should state it as such, with the data to support their statements.

    Nevertheless, there is no conclusive evidence of significant benefits of electrical stim/FES. There's data supporting both advocates and nay sayers. Much of it depends on the specifics of what one is studying, doesn't it. Individual's might be recieving some benefit in using FES. Maybe they aren't significant benefits or restoring muscle function per se, but if there are noticeable (or even percieved) results- ie increased mass, and that helps to motivate a person to excercise harder, improve strength and conditiong of functioning muscles, then all the power to em. If it serves to simply improve one's appearance by increasing bulk to otherwise diminished muscles, then so be it. This can help improve one's confidence and self image, which can help personal drive and initiative to further improve health and care of one's body. Whatever the reasons, if there is no harm being done, through the use of such machines, then why shouldn't a person use them.

    "Harm". Harm can also be in the form of being taken advantage of by profiteers, who will promise anything. So, as long as one makes a fully informed decision. That is their choice.

  7. #17
    Here you are Don http://electrologic.com/biblio.htm

    I will anxiously await the unveiling of your FES beating therapy.

  8. #18
    Senior Member ~Patrick~'s Avatar
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    We know what Dr. Young's medical and research background is and hold him in high esteem. What is your background and what research, not articles, have you drawn this conclussion on FES? What is your relationship with the SCI world?

    Thank You
    ~Pat~

    T-10 complete
    10/08/01



  9. #19
    Senior Member Kaprikorn1's Avatar
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    Hey Don Quixote...How much do YOU make for selling one of these "galvanism" machines that you promise will make a complete walk in 8 years?

    Maybe you should spend a little more on your web site.

    Sell your crap somewhere else.

    Kap

    "It's not easy being green"

  10. #20
    Don Quixote,

    You are making some pretty sweeping statements, i.e. "joke of electrical stimulation", "unwitting charlatantry", and "ignorant neuroscientists". You appear to be basing your belief that electrotherapy (referring to surface stimulation with commercial devices) is useless because:

    1. there is "no evidence that electrical stimulation has any effect on slowing or reversing atrophy"
    2. "no body builder uses electrotherapy" and NASA has decided not to use FES to build or prevent muscle atrophy of astronauts in space.
    3. "restoration of cross-sectional area of type II muscle can be accomplished only be strong physical exercise, the traditional resistance exercises, or the introduction of an electrical charge to the neuromuscular junction from which the type II fiber grows"
    4. "...the devices... don't pass electrical charge", the FDA will not approve machines that pass more than "half of one thousandth of an ampere", "a prohibition that dates to 1855".

    Let me discuss each of these points sequentially below.

    You state that there is "no evidence that electrical stimulation has any effect on slowing or reversing atrophy". There is evidence that electrical stimulation of muscle can increase bulk and strength of paralyzed muscle, and even reverse muscle atrophy and osteopenia in bones of stimulated legs. There are of course many studies but I will cite only two. Baldi, et al. (1998) from Ohio State University published a study assessing whether unloaded FES isometric contractions and FES-cycle ergometry could prevent muscle atrophy. They tested 26 subjects who started <3 months after injury and found that 3 months of FES-cycle ergometry but not FES-isometric contractions prevented muscle atrophy and caused significant muscle hypertrophy after 6 months. Belanger, et al. [2000) from the University of Quebec studied the effects of FES and resistance training on osteopenia, stimulating the left quadriceps of 14 subjects with spinal cord injury, comparing these against the right quadriceps of the individuals and 14 unstimulated control subjects. They concluded that osteopenia of the distal femur and proximal tibia and the loss of strength of the quadriceps can be partly reversed by regular FES-assisted training.

    You state that "no body builder uses electrotherapy". I had pointed out that this is a spurious argument because able-body builders can exercise muscles much more effectively through voluntary muscle activation against resistance. NASA probably chose to test voluntary muscle exercise in astronauts because it is more effective and efficient than FES. Furthermore, surface stimulation of muscles can improve neuromuscular function. Marqueste, et al., (2003) recorded muscle force, surface EMG, and M-wave of the rectus femoris and flexor digitorum brevis during a 6-week period of FES. Although the M-wave did not change after FES, they found that FES improved muscle function and activation.

    I agree that surface FES stimulation with commercial devices does not increase type II fiber diameters. Greve, et al. (1993) showed the FES did not change diameters of type I, IIa, and IIb fibers although the number of type IIa fibers increased. Crameri, et al., (2002) showed FES increased vastus lateralis work output, cross-sectional area of the muscle, vascularization, and muscle enzymes but reduced the percentage of type II fibers and myosin heavy chains. Type I or slow-twitch fibers are responsible for tone and posture while type II or fast-twitch fibers are used for phasic movements. FES induced muscle hypertrophy therefore is likely to be due to increase in type I muscle fibers. On the other hand, there may be some benefits to transforming fast fatigable muscles towards slower, fatigue-resistant ones (Pette & Vrbova, 1999).

    I agree that commercial devices do not pass enough current to activate denervated muscles. Kern, et al. (2002) showed that high currents are necessary and sufficient to activate denervated muscles. They were able to achieve tetanic contraction of such muscle with intense stimulation (pulse duration 30-50 msec, 16-25 Hz, and pulse amplitudes of up to 250 mA). They passed these enormous currents by using large electrode pads, reducing the current density. They estimated that this stimulation approach restored 2-4 million muscle fibers per quadriceps muscle of 3-4 years in muscles that had been denervated for 15-20 years. However, commercial FES surface stimulators can activate nerves that in turn activate muscles, as well as spinal reflexes that activate muscles. Although not particularly efficient, neuromuscular stimulation with surface electrodes can activate innervated muscles sufficiently to generate limb movements against resistance.

    Wise.

    References

    • Baldi JC, Jackson RD, Moraille R and Mysiw WJ (1998). Muscle atrophy is prevented in patients with acute spinal cord injury using functional electrical stimulation. Spinal Cord. 36: 463-9. Department of Physical Medicine and Rehabilitation, Ohio State University, Columbus 43210, USA. Severe muscle atrophy occurs rapidly following traumatic spinal cord injury (SCI). Previous research shows that neuromuscular or 'functional' electrical stimulation (FES), particularly FES-cycle ergometry (FES-CE) can cause muscle hypertrophy in individuals with chronic SCI (> 1 year post-injury). However, the modest degree of hypertrophy in these already atrophied muscles has lessened earlier hopes that FES therapy would reduce secondary impairments of SCI. It is not known whether FES treatments are effective when used to prevent, rather than reverse, muscle atrophy in individuals with acute SCI. This study explored whether unloaded isometric FES contractions (FES-IC) or FES-CE decreased subsequent muscle atrophy in individual with acute SCI (< 3 months post-injury). Twenty-six subjects, 14-15 weeks post-traumatic SCI, were assigned to control, FES-IC, or FES-CE against progessively increasing resistance. Subjects were involved in the study for 3 or 6 months. Total body lean body mass [TB-LBM), lower limb lean body mass [LL-LBM), and gluteal lean body mass [G-LBM) were determined before the study, and at 3 and 6 months using dual energy X-ray absorptiometry [DEXA). Controls lost an average of 6.1%, 10.1%, 12.4%, after 3 months and 9.5%, 21.4%, 26.8% after 6 months in TB-LBM, LL-LBM and G-LBM respectively. Subjects in the FES-IC group consistently lost less lean body mass than controls, however, only 6 month G-LBM loss was significantly attenuated in this group relative to the controls. In the FES-CE group, LL-LBM and G-LBM loss were prevented at both 3 and 6 months, and TB-LBM loss was prevented at 6 months. In addition, FES-CE significantly increased G-LBM and LL-LBM after 6 months of training relative to pre-training levels. Within the control group, there was no significant relationship between LL-LBM loss [3 and 6 months) and the number of days between injury and baseline measurement. In summary, this study shows that FES-CE, but not FES-IC, training prevents muscle atrophy in acute SCI after 3 months of training, and causes significant hypertrophy after 6 months. The magnitude of differences in regionalized LBM between controls and FES-CE subject raises hopes that such treatment may indeed be beneficial in preventing secondary impairments of SCI if employed before extensive post-injury atrophy occurs.

    • Belanger M, Stein RB, Wheeler GD, Gordon T and Leduc B (2000). Electrical stimulation: can it increase muscle strength and reverse osteopenia in spinal cord injured individuals? Arch Phys Med Rehabil. 81: 1090-8. Departement de Kinanthropologie, Universite du Quebec a Montreal, Canada. OBJECTIVE: To study the extent to which atrophy of muscle and progressive weakening of the long bones after spinal cord injury (SCI) can be reversed by functional electrical stimulation (FES) and resistance training. DESIGN: A within-subject, contralateral limb, and matching design. SETTING: Research laboratories in university settings. PARTICIPANTS: Fourteen patients with SCI (C5 to T5) and 14 control subjects volunteered for this study. INTERVENTIONS: The left quadriceps were stimulated to contract against an isokinetic load (resisted) while the right quadriceps contracted against gravity (unresisted) for 1 hour a day, 5 days a week, for 24 weeks. MAIN OUTCOME MEASURES: Bone mineral density (BMD) of the distal femur, proximal tibia, and mid-tibia obtained by dual energy x-ray absorptiometry, and torque (strength). RESULTS: Initially, the BMD of SCI subjects was lower than that of controls. After training, the distal femur and proximal tibia had recovered nearly 30% of the bone lost, compared with the controls. There was no difference in the mid-tibia or between the sides at any level. There was a large strength gain, with the rate of increase being substantially greater on the resisted side. CONCLUSION: Osteopenia of the distal femur and proximal tibia and the loss of strength of the quadriceps can be partly reversed by regular FES-assisted training.

    • Marqueste T, Hug F, Decherchi P and Jammes Y (2003). Changes in neuromuscular function after training by functional electrical stimulation. Muscle Nerve. 28: 181-8. Institut Federatif de Recherches Jean Roche (IFR 11), Faculte de Medecine Nord, Universite de la Mediterranee (Aix-Marseille II), Boulevard Pierre Dramard, 13916 Marseille, France. We examined whether the neuromuscular function of rectus femoris (RF) and flexor digitorum brevis (FDB) in humans was modified after a 6-week training period of functional electrical stimulation (FES), and whether any effects persisted at the end of a 6-week post-FES recovery period. In both the stimulated and contralateral nonstimulated muscles, we recorded the muscle force, surface electromyogram, and M wave, and also measured the root mean square (RMS) and the median frequency (MF) during static contraction sustained until exhaustion at 60% of maximal voluntary contraction (MVC). FES was performed with symmetric biphasic pulses, with a ramp modulation of both the stimulation frequency and pulse duration. No changes in MCV and endurance time to exhaustion occurred in nonstimulated muscles, whereas a significant MVC increase occurred immediately after FES in RF (+14 +/- 5%) and FDB (+13 +/- 5%), these effects persisting 6 weeks after the end of FES. In FDB, FES also elicited a significant increase in endurance time to exhaustion (+18 +/- 7%). The M-wave characteristics never varied after FES, but a marked attenuation occurred in the MF decrease and the RMS increase measured at endurance time to sustained 60% MVC, especially in FDB, which contains the higher proportion of type II fibers. These data indicate that FES improves muscle function and elicits changes in central muscle activation. The benefits of FES were greater in FDB, which is highly fatigable, and persisted for at least a 6-week period.

    • Greve JM, Muszkat R, Schmidt B, Chiovatto J, Barros Filho TE and Batisttella LR (1993). Functional electrical stimulation (FES): muscle histochemical analysis. Paraplegia. 31: 764-70. Department of Rehabilitation, Clinics Hospital, School of Medicine, University of Sao Paulo, Brazil. Functional electrical stimulation (FES) has been used in Brazil since 1989 to obtain functional improvement in paraplegic patients' orthostasis and locomotion. The aim of this paper is to evaluate the histochemical changes observed in the quadriceps femoris muscle following the use of FES. We studied four patients with traumatic spinal cord lesions at T4-10 level, Frankel A, all within 12-24 months postlesion. They were all submitted to FES using the following criteria: square-wave, 20-30 Hz frequency, pulses of 0.003 seconds, time of stimulation 5 seconds, resting interval 10 seconds. The stimulation was applied during 90 consecutive days, 30 minutes each time, twice daily. The interval between the stimulations was 6 hours. Quadriceps muscle biopsies were performed before and after the use of FES. We used ATPase technique for the histochemical analysis, where three different dying patterns can be observed for the three types of muscular fibres (I, IIa and IIb). The two samples from each patient were analysed measuring the fibres' diameters and their index of atrophy, and counting the total number of each type of fibre in each sample. The mean total number of fibres in each sample was 256 +/- 12.3. The results showed that the sizes of the three types of fibres were not modified with the use of FES; the number of type IIa fibres increased in a significant fashion, after using of FES.

    • Crameri RM, Weston A, Climstein M, Davis GM and Sutton JR (2002). Effects of electrical stimulation-induced leg training on skeletal muscle adaptability in spinal cord injury. Scand J Med Sci Sports. 12: 316-22. Sports Medicine Research Unit, Department of Rheumatology, Bispebjerg Hospital, Copenhagen, Denmark. Neuromuscular electrical stimulation has grown in popularity as a therapeutic device for training and an ambulation aid to human paralyzed muscle. Despite its current clinical use, few studies have attempted to concurrently investigate the functional and intramuscular adaptations which occur after electrical stimulation training. Six individuals with a spinal cord injury performed 10 weeks of electrical stimulation leg cycle training (30 min d(-1), 3 d week(-1)). The paralyzed vastus lateralis muscle showed significant alterations in skeletal muscle characteristics after the training, indicated by an improvement in total work output (52-112 kJ; P < 0.05), an increase in fiber cross-sectional area [18 to 41 x 10[2) microm[2); P < 0.05), a reduction in the percentage of type IIX fibers [75% to 12%; P < 0.05), a decrease in myosin heavy chain IIx [68% to 44%; P < 0.05), an increase in capillary density [2-3.5 capillaries around fiber; P < 0.05) and increases in activity levels of citrate synthase [7-16 mU mg[-1) protein) and hexokinase [1.2-2.4 mU mg[-1) protein). This study showed that 10 weeks of electrical stimulation training of human paralyzed muscle induces concurrent improvements in functional capacity and oxidative metabolism.

    • Pette D and Vrbova G (1999). What does chronic electrical stimulation teach us about muscle plasticity? Muscle Nerve. 22: 666-77. Faculty of Biology, University of Konstanz, Germany. The model of chronic low-frequency stimulation for the study of muscle plasticity was developed over 30 years ago. This protocol leads to a transformation of fast, fatigable muscles toward slower, fatigue-resistant ones. It involves qualitative and quantitative changes of all elements of the muscle fiber studied so far. The multitude of stimulation-induced changes makes it possible to establish the full adaptive potential of skeletal muscle. Both functional and structural alterations are caused by orchestrated exchanges of fast protein isoforms with their slow counterparts, as well as by altered levels of expression. This remodeling of the muscle fiber encompasses the major, myofibrillar proteins, membrane-bound and soluble proteins involved in Ca2+ dynamics, and mitochondrial and cytosolic enzymes of energy metabolism. Most transitions occur in a coordinated, time-dependent manner and result from altered gene expression, including transcriptional and posttranscriptional processes. This review summarizes the advantages of chronic low-frequency stimulation for studying activity-induced changes in phenotype, and its potential for investigating regulatory mechanisms of gene expression. The potential clinical relevance or utility of the technique is also considered.

    • Kern H, Hofer C, Modlin M, Forstner C, Raschka-Hogler D, Mayr W and Stohr H (2002). Denervated muscles in humans: limitations and problems of currently used functional electrical stimulation training protocols. Artif Organs. 26: 216-8. Ludwig Boltzmann Institute of Electrostimulation and Physical Rehabilitation, Department of Physical Medicine, Wilhelminenspital, Wien, Austria. helmut.kern@phys.wil.magwien.gv.at. Prior clinical work showed that electrical stimulation therapy with exponential current is able to slow down atrophy and maintain the muscle during nonpermanent flaccid paralysis. However, exponential currents are not sufficient for long-term therapy of denervated degenerated muscles (DDMs). We initiated a European research project investigating the rehabilitation strategies in humans, but also studying the underlying basic scientific knowledge of muscle regeneration from satellite cells or myoblast activity in animal experiments. In our prior study, we were able to show that high-intensity stimulation of DDMs is possible. At the beginning of training, only single muscle twitches can be elicited by biphasic pulses with durations of 120-150 ms. Later, tetanic contraction of the muscle with special stimulation parameters (pulse duration of 30-50 ms, stimulation frequency of 16-25 Hz, pulse amplitudes of up to 250 mA) can improve the structural and metabolic state of the DDMs. Because there are no nerve endings for conduction of stimuli, large-size, anatomically shaped electrodes are used. This ensures an even contraction of the whole muscle. Contrary to the current clinical knowledge, we were able to stimulate and train denervated muscle 15-20 years after denervation. The estimated amount of muscle fibers that have to be restored is about 2-4 million fibers in each m. quadriceps. To rebuild such a large number of muscle fibers takes up to 3-4 years. Despite constant stimulation parameters and training protocols, there is a high variation in the developed contraction force and fatigue resistance of the muscle during the first years of functional electrical stimulation.

    [This message was edited by Wise Young on 03-10-04 at 07:12 AM.]

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