# An elementary question - Percussive waveform moving through human tissue

I need a better understanding and explanation of how a percussion wave form can move through biological soft tissue. I know that human soft tissue functions microscopically in a fluid environment however I also understand that there are also obstructive forces in the way of a wave moving in a straight line when it comes to said soft tissue. Without going into further detail regarding my question, can anyone give me a good understanding which might then instigate an additional question!

berkeman
Mentor
I need a better understanding and explanation of how a percussion wave form can move through biological soft tissue. I know that human soft tissue functions microscopically in a fluid environment however I also understand that there are also obstructive forces in the way of a wave moving in a straight line when it comes to said soft tissue. Without going into further detail regarding my question, can anyone give me a good understanding which might then instigate an additional question!
Welcome to the PF, doctor.

It is probably related somewhat to how ultrasound moves through the body and is used to produce images. What is the frequency range of your percussion waves? Is the amplitude similar to what is used in typical ultrasonic imaging, or are you looking at higher amplitude percussion waves like blast waves?

Welcome to the PF, doctor.

It is probably related somewhat to how ultrasound moves through the body and is used to produce images. What is the frequency range of your percussion waves? Is the amplitude similar to what is used in typical ultrasonic imaging, or are you looking at higher amplitude percussion waves like blast waves?
Thank you for responding so quickly. This is where my physics of waves is VERY limited. My understanding simply, is that the difference between all wave forms i.e., sound, light, electrical, vibration, etc, are a matter of frequency. My guttural response (as we do not have this well defined) is that through our instrument delivered force to the upper cervical spinal complex, we utilize a blast from a hammer hit to a solenoid coil which delivers a percussion wave through the soft tissue at an angle that has been calculated to provide the highest degree of leverage to bypass muscular hold of the first cervical vertebra in malposition by stimulating the motor nerves to alter their over-firing. I'm challenged because I feel if I could understand friction obstacles at the level of the bio-molecular level I could have a better grasp on how to improve on how I am applying that force and in which direction.

I have a lot of questions in the way of application of force on biological tissue as well as how the direction of that force is applied, however I feel I need to understand some basics!?

Are you interested in a somewhat biophysical answer focused on trauma?:

https://www.ncbi.nlm.nih.gov/books/NBK299193/

Or

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4160106/

If you could clarify your goal maybe we could help. Note: I'm just a biologist, @Andy Resnick trends more toward Biophysics and can likely help, too.
My goal is to evaluate our use of an 8 pound percussion wave force delivered at a calculated Z and Y vector through soft tissue at the level of the 1st cervical vertebra (stabilized only by soft tissue), understand why our outcomes are fantastic on some and but less effective on others, and potentially change how we do what we do just a little to improve our outcomes.

Thank you so much for directing me to the books and articles you noted. I know they will help me. I am really appreciating this wonderful platform of excellent minds that I can ask questions in.

berkeman
Mentor
My guttural response (as we do not have this well defined) is that through our instrument delivered force to the upper cervical spinal complex, we utilize a blast from a hammer hit to a solenoid coil which delivers a percussion wave through the soft tissue at an angle that has been calculated to provide the highest degree of leverage to bypass muscular hold of the first cervical vertebra in malposition by stimulating the motor nerves to alter their over-firing.
I assume you are not doing this on cadavers, since you talk about active electrical activity in the muscles around C1-C3. Is this clinical research being done under the FDA or some other authorizing body? What kind of a waiver do your patients need to sign to go through this experimental treatment? Are there any journal articles or medical textbooks that describe this procedure?

https://www.fda.gov/ScienceResearch/SpecialTopics/RunningClinicalTrials/default.htm

I assume you are not doing this on cadavers, since you talk about active electrical activity in the muscles around C1-C3. Is this clinical research being done under the FDA or some other authorizing body? What kind of a waiver do your patients need to sign to go through this experimental treatment? Are there any journal articles or medical textbooks that describe this procedure?

https://www.fda.gov/ScienceResearch/SpecialTopics/RunningClinicalTrials/default.htm
I'm sorry if I have caused some anxiety over my post. My comments regarding motor activation has to do the nervous system of the body. Our instrument has been FDA approved and does not deliver electricity to the consumer. Please look up www.globalao.com to learn more about what I am discussing. And, there are numerous sources on the in research having been written and in the process of being written up and studied on the efficacy of upper cervical specific chiropractic. I, myself, am working on writing literature reviews to sift through what is already known and I am working on utilization of the chiropractic schools to conduct specific studies.

I would like to focus on my questions so that I can continue to learn for myself as a dedicated and disciplined practitioner. Thank you for adding the link to running clinical trials. Our group and chiropractic community is conducting ongoing studies as quickly and effectively as we can!

berkeman
Mentor
Our instrument has been FDA approved and does not deliver electricity to the consumer. Please look up www.globalao.com to learn more about what I am discussing. And, there are numerous sources on the in research having been written and in the process of being written up and studied on the efficacy of upper cervical specific chiropractic.
Thanks for posting that. BTW, do you have a link to the actual instrument? I was not able to find it at the GlobalAO website. Just a journal article describing their study. Thanks.

Thank you. Yes, let me know of the link does not come through correctly.

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berkeman
Mentor
Wow, that's a big needle! Does it go all the way through her neck?

(J/K)

1/4" diameter stylus and a resounding "no" it does not go through the skin...only touches it. Ok, but, I'm still in pursuit of my original question. I'll keep plugging away and again, I really do appreciate your responses and interest. I too LOVE science.

Andy Resnick
My understanding simply, is that the difference between all wave forms i.e., sound, light, electrical, vibration, etc, are a matter of frequency.
That is very untrue- just because those phenomena can often be described in terms of wave propagation does not mean they are all the same. It appears you are examining sound (pressure) wave propagation- a mechanical process, and the tissue responds mechanically.

My guttural response (as we do not have this well defined) is that through our instrument delivered force to the upper cervical spinal complex, we utilize a blast from a hammer hit to a solenoid coil which delivers a percussion wave through the soft tissue at an angle that has been calculated to provide the highest degree of leverage to bypass muscular hold of the first cervical vertebra in malposition by stimulating the motor nerves to alter their over-firing. I'm challenged because I feel if I could understand friction obstacles at the level of the bio-molecular level I could have a better grasp on how to improve on how I am applying that force and in which direction.
You are not applying a force- you are applying a pressure transient. Physics 1 may treat these as interchangeable, but for your application you should not. The pressure wave will diffract as it propagates and also reflect from tissue interfaces (the principle of ultrasound imaging). Not sure how application of pressure transients will excite nerve tissue- what is the threshold stimulation, for example. A related application may be a lithotripter:

https://en.wikipedia.org/wiki/Extracorporeal_shock_wave_lithotripsy

If you learn how the shock wave is controlled so that it targets a specific volume, you may gain some insight for your application.

Evo, jim mcnamara and berkeman
Thank you for responding. You'll have to excuse my oversimplification of certain concepts and/or phenomena! I'm trying to learn the difference between Sound wave propagation and percussion wave propagation. I then want to find out how much my percussion wave dissipates after traveling a short distance through soft tissue medium from its force, in pounds, discharge.

I also read the link from wikipedia so I'm still searching. Your time and words are really appreciated

Nidum
Gold Member
(1) Much depends on the initial conditions .

If the hammer is forcefully held against the body tissue before the impact is applied then much more impact force will be transmitted than where the hammer is only held lightly against the tissue or where there is no pre contact at all .

When the tissue is pre-compressed it will become relatively stiffer in the direction of force application .

(2) The vertebra and tissue structure and it's response to an impact load can probably be modelled quite well using normal engineering methods .

Possibly something like this has been done before using ANSYS ?

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Nidum
Gold Member
I think that it might actually be feasible to set up a 1D model of this system which would be good enough to give useful answers .

Certainly worth looking at before moving on to more complex models .

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I appreciate your thoughts however not certain I agree as I've actually seen and experienced the opposite. Point is, this question of force load proportional to power does not result in a consistent result. I will definitely look into your recommendations. Thank you!

Tom.G