Someone had likened the injury to the nerves to an electrical current, where a wire can only transfer a certain amount of electricity. So a damaged nerve transfers less than full strength or less current. I found that to be a good analogy. However now I have a question. Dustin's arm is now what they call "functional". Meaning he can make all the movements and fire all the muscles. Now getting back to that electrical thing, so is it possible then to strengthen the muscles to make the arm "useful" or because it still receives less current is it not possible to strengthen it enough? If you think of bodybuilders they still have the same amount of "current" but the muscles keep getiing bigger. So was just wondering.
Sue
Strengthening the bpi arm....
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marieke
- Posts: 1627
- Joined: Fri Apr 01, 2005 6:00 pm
- Injury Description, Date, extent, surgical intervention etc: LOBPI
no external rotation against gravity, can only go to 90 degree fwd flexion, no hand-to-mouth
1 surgery at age 14 (latissimus dorsi transfer). In 2004, at age 28 I was struck with Transverse Myelitis which paralyzed me from the chest down. I recovered movement to my right leg, but need a KAFO to walk on my left leg. I became an RN in 2008. - Location: Montreal, Qc, Canada
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Re: Strengthening the bpi arm....
It also depends on the type of muscle fibers one has.. slow twitch vs fast twitch. Fast twitch is more along the lines of people who use their muscles in short bursts (gymnasts, figure skaters) and slow twitch is for long distances, runners for example. Body builders over-train their bodies to get that mass as well.
It's not so simple and cut and dry as his arm is now "fully" functional, there was nerve damage that may still exist, though minimal that can make the process of getting bigger muscle mass impossible. For him, only time will tell... if they say there is no more nerve damage then he will just have to keep working at it
It's not so simple and cut and dry as his arm is now "fully" functional, there was nerve damage that may still exist, though minimal that can make the process of getting bigger muscle mass impossible. For him, only time will tell... if they say there is no more nerve damage then he will just have to keep working at it
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BaldPlumber
- Posts: 11
- Joined: Wed Jan 27, 2010 2:36 am
Re: Strengthening the bpi arm....
That makes sense. Functionality does not imply full recovery or full strength. I have noticed that initial recovery of function also means months and months of nerve and muscle recovery. As all here know, spontaneous recovery is a little misleading but each and every functional advancement should be celebrated and not hurried.
This is a slow and steady process and each improvement enriches your life immeasurably compared to the people who have no hope of advancement, so we are truly lucky.
Good luck.
This is a slow and steady process and each improvement enriches your life immeasurably compared to the people who have no hope of advancement, so we are truly lucky.
Good luck.
Re: Strengthening the bpi arm....
There are a few different aspects of nerve recovery that can impact how "strong" the muscle is able to get. One is essentially "bandwidth". A nerve is like a a conduit which carries many wires. For a nerve innervating a muscle for movement, these wires are motor neurons. Each individual motor neuron intefaces with a group of muscle cells, and controls the contraction of those cells. The amount of motor control in a muscle is directly related to how many different groups of muscle cells are innervated separately. When the main conduit nerve is damaged, or completely severed and then reattached, some motor neurons just don't survive, some survive (or are reattached) and regrow back to the same original muscle, some regrow down a different pathway and reach a different target muscle, and some may regrown but never reach a muscle at all.
Thus, the original muscle is left with a reduced number of motor neurons to innervate all the fibers. So while some muscle fibers may end up reattached to their original motor neurons, any muscle fibers left without connections will typically be "recruited" by existing viable motor neurons. This results in reduced "bandwidth" -- fewer motor neurons controlling larger groups of muscle fibers. The innate efficiency of the muscle - its ability to adaptively contract according to load and demand - is reduced because there are fewer motor neurons controlling larger groups of muscle fibers which may not be optimal to contract together.
This reduced optimization of muscle control may directly impact the production of the neurotropic factors necessary for building strength, endurance and speed. With the mis-match of motor neurons and their connected muscle fibers, it may be difficult or impossible to design an exercise program that would result in much increase in strength or mass of the muscle fibers. For example, under one exercise regimen, some fibers may be triggered to grow, but the other muscles exercised at the same time (due to the lack of finer control) may be damaged by the same amount of work, so that the net is that there is no increase in strength or muscle bulk.
The other issue that can get in the way of building muscles and strength is cross innervation. Some of the damaged motor neurons may end up innervating muscles that have the opposite function of what that motor neuron originally controlled. So the brain is trying to control the biceps, for instance, by triggering the motor neurons originating in the part of the brain that developed for "biceps". But if a sub-section of those motor neurons are actually now controlling triceps muscles, when the brain says "biceps on" the movement itself will not be very strong because the diverted motor neurons are opposing the original function. In some situations it may be possible to actually increase muscle mass but still not achieve an increase in strength, due to the isometric nature of any muscle contractions that may be produced.
The brain is able to re-organize to a certain extent, but part of the problem is bio-feedback. In order for the brain to re-target which portions control which muscles, some effect needs to be observable. But if the cross-innervation is bad enough, the brain will never be able to "recognize" that a certain portion controls biceps while another controls triceps, because no matter what is tried, the biceps don't actually move the arm (even though they contract). The brain may eventually just "give up" and say "this muscle is not connected". This is one of the motivations for using botox. If co-contractions are preventing the biofeedback necessary to develop control of a certain muscle, botox can be used to temporarily disable the contractions in the opposing muscle in order to allow the brain to "see" the first muscle and hopefully develop control of it. Whether or not that control will persist after the opposing muscle comes back "online" strongly depends on how mixed the innervation is and how well the brain can use the temporary biofeedback to differentiate the shuffled motor neuron connections. Increasing the control of the muscle will always result in better contractions and increase the potential for more strength.
Kate
Thus, the original muscle is left with a reduced number of motor neurons to innervate all the fibers. So while some muscle fibers may end up reattached to their original motor neurons, any muscle fibers left without connections will typically be "recruited" by existing viable motor neurons. This results in reduced "bandwidth" -- fewer motor neurons controlling larger groups of muscle fibers. The innate efficiency of the muscle - its ability to adaptively contract according to load and demand - is reduced because there are fewer motor neurons controlling larger groups of muscle fibers which may not be optimal to contract together.
This reduced optimization of muscle control may directly impact the production of the neurotropic factors necessary for building strength, endurance and speed. With the mis-match of motor neurons and their connected muscle fibers, it may be difficult or impossible to design an exercise program that would result in much increase in strength or mass of the muscle fibers. For example, under one exercise regimen, some fibers may be triggered to grow, but the other muscles exercised at the same time (due to the lack of finer control) may be damaged by the same amount of work, so that the net is that there is no increase in strength or muscle bulk.
The other issue that can get in the way of building muscles and strength is cross innervation. Some of the damaged motor neurons may end up innervating muscles that have the opposite function of what that motor neuron originally controlled. So the brain is trying to control the biceps, for instance, by triggering the motor neurons originating in the part of the brain that developed for "biceps". But if a sub-section of those motor neurons are actually now controlling triceps muscles, when the brain says "biceps on" the movement itself will not be very strong because the diverted motor neurons are opposing the original function. In some situations it may be possible to actually increase muscle mass but still not achieve an increase in strength, due to the isometric nature of any muscle contractions that may be produced.
The brain is able to re-organize to a certain extent, but part of the problem is bio-feedback. In order for the brain to re-target which portions control which muscles, some effect needs to be observable. But if the cross-innervation is bad enough, the brain will never be able to "recognize" that a certain portion controls biceps while another controls triceps, because no matter what is tried, the biceps don't actually move the arm (even though they contract). The brain may eventually just "give up" and say "this muscle is not connected". This is one of the motivations for using botox. If co-contractions are preventing the biofeedback necessary to develop control of a certain muscle, botox can be used to temporarily disable the contractions in the opposing muscle in order to allow the brain to "see" the first muscle and hopefully develop control of it. Whether or not that control will persist after the opposing muscle comes back "online" strongly depends on how mixed the innervation is and how well the brain can use the temporary biofeedback to differentiate the shuffled motor neuron connections. Increasing the control of the muscle will always result in better contractions and increase the potential for more strength.
Kate