Dear Colleague,

In anatomy we performed a similar pilot study a couple of years ago. Measurement were performed starting by taking colour photographs of anatomical specimens used for conventional teaching purposes (the anatomical landmarks indicated by coloured pins) in standard positions, so there were no movement disturbances.

Afterwards (again no movement disturbances) on prints (later at the PC screen) of these photographs, using some superimposed scaling techniques, more measurements coud be done, and calculations were performed.

You can get impressions of our work by reading these two papers, which currently are both on our name at ResearchGate :

- Article: Low back pain, multifidus muscles, and lumbar stability - an anatomical approach.

- Dataset: Low back pain, multifidus muscles and lumbar stability - an anatomical approach; References; Poster

Hoping that you find some inspiration from our approach, and wishing you success,

with kind regards,

Koos Jaap van Zwieten

As you probably know, heads on cadavers large and small are all placed on flat tables, making it difficult to place the head ventral side down on the table without artificially skewing the head dorsally.  This alters the natural in vivo line of posture where the face is naturally ventral to the torso and creates a lordotic positional artifact.   I never came across a massage-style dissection table in my experience teaching gross anatomy at UPenn that might help you overcome this artifact, as such I would make the following recommendations prior to dissection: either (1) shift the cadaver superiorly on the table with the chin off of the table as would be positioned in a professional massage table (as strange as that may sound) to replicate a more neutral postural position; or (2) elevate the cadaver's torso relative to the head allowing it to situate in a more natural ventral position.  Hope that this helps.        

Dear colleagues, thank you very much for your nice recommendations. I think they will be of great help in the experiment.

Dr. Zwieten I read the papers you mentioned about multifidius muscles, and interested to learn about further. So, I replied your kind message.

Dr. Meyer, to be honest, I did not know that head could be a problem along the way. What you said is very critical and I would definitely follow your suggestions. Proper positioning of natural posture is very important to achieve in vivo muscle line of action. It is unfortunate that current dissection tables are not suitable for head natural positioning.

I am actually planning to dissect only on one side of the spine, assuming it is symmetrical on the sagittal plane. Of course, before the dissection, I will make sure the body do not have any spinal deformity that could possibly revoke symmetry assumption. Let's say I will work on the right side of the cadaver, then I am thinking to connect every vertebrae via some metal plates and screws in the different regions, i.e. cervical, thoracic and lumbar, so that at least they do not move with respect to each other during the process. As I have to turn they body in the prone and supine positions several times, this is the method I am thinking to apply. I am also wondering your thoughts about positioning of the spine in the upright standing posture (by hanging it somehow) instead of dissecting on the conventional table.

Correcting the position of the head may be easier using the foam blocks which are used to position a patient prone for anaesthesia, as they are anatomical.

 Riza,

It is a mistake to think that there is a local and specific origin and insertion of a muscle. See: Huijing, Peter A, and Guus C Baan. "Myofascial Force Transmission Via Extramuscular Pathways Occurs Between Antagonistic Muscles." Cells Tissues Organs 188, no. 4 (2008): doi:10.1159/000118097. and several others by him and his group.

Dear colleague,

For the fixation of the vertebrae, you could consider using a standard posterior fixation system as is used in spinal surgery. These systems are quite similar between different manufacturers and use pedicle screws and rods to interconnect the vertebrae. 

With kind regards,

Roderick Holewijn

Dear Stephen,

I indeed know that muscles do not have single origin and insertion, and myofascial force transmission exist. However, I am working on musculoskeletal modeling, and muscle force transmission phenomena is far beyond the scope of spinal modeling at the moment.

Kind regards,

Riza Bayoglu.

Dear Roderick,

Thank you for suggestion. I already thought about using such a fixation system. However, the problem is that I can only apply it on one side of the spine as I will resect muscles on the other side. Do you think it will provide enough rigidity if I apply it on one side only? I do not have any experience with this kind of devices and want to make sure there will be no change in the relative positions of vertebrae and ribs with respect to each other. Ideally, I want no such movement to achieve same orientation and position between computed tomography images and during the dissection.

kind regards,

Riza Bayoglu.

Dear Riza,

Do you have actually any embalmed dissected back dissections that have been done.

Could possibly send you photos.

We dissect all the organs out and take off transverse section of the skull above expose the aorta spinal column with sympathetic nervous system.

Body is turned over and back dissected.

Send me an email and maybe with permission I can forward photograh.

Glenn Wilcher

University of New South Wales Sydney Australia.

 Dear Wilcher,

Thank you for your message. I just sent an email to your mail address.

Kind regards,

Riza Bayoglu.

this link may help you

http://www.dnatube.com/video/21681/Lec-24-Gross-Anatomy--Superficial-and-Deep-Back-Muscles

Dear Riza,

If you don't put extreme forces on the spine a standard posterior fixation system on one side will provide enough stability. Though, I would advise you to have an orthopedic surgeon/resident insert the screws and rods if you do not have experience with this system. If the system is not inserted with the correct technique it will lose fixation strength (the screws have to be in the canal of the the pedicle and "catch" enough cortical bone).

With kind regards,

Roderick Holewijn