an experiment done in 2001 showing what happens to the muscles during lengthenin

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thatdude, may i know why you here if you will not do this?

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Sorry TBike, I was addressing the Q: to "thatDude950"

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see my post history re: my own BDD

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Quote from: TIBIKE200 on March 18, 2016, 08:58:06 AMthese studies clearly show that 1mm per day distraction is harmful for the muscles (I believe the same applies for femoral lengthening and might also explain why there isnt a single decent case of recovery for femural lengthening).

 0.75mm which is the common distration rate for tibia today seems to be the upper border for safety (although not 100% safe at all). I believe that the original 0.66mm per day was indeed the best way to ensure muscles are free of massive damage and also reducing the risk of pre-consolidation.

But, does that translate to humans given the size differences as to the leg of a rabbit? Genuine question, I have no idea.

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Quote from: Nightwish on March 18, 2016, 01:53:55 PMBut, does that translate to humans given the size differences as to the leg of a rabbit? Genuine question, I have no idea.

it's a risk I prefer not to take on myself

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Quote from: Nightwish on March 18, 2016, 01:53:55 PMBut, does that translate to humans given the size differences as to the leg of a rabbit? Genuine question, I have no idea.

Yeah tough to tell since humans are so much bigger than rabbits.  you can't definitively make that conclusion as the research pointed out.  "It is not possible to compare absolute values between patients and experimental models."  If you were to compare absolutes, then it would be a bad idea to lengthen more than 2cm (the amount of lengthening on the rabbits). 

Their main conclusion does support the idea that slower distraction is better (as long as you don't risk pre consolidation like TRS said).

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Quote from: goldenegg on March 18, 2016, 04:54:24 PMYeah tough to tell since humans are so much bigger than rabbits.  you can't definitively make that conclusion as the research pointed out.  "It is not possible to compare absolute values between patients and experimental models."  If you were to compare absolutes, then it would be a bad idea to lengthen more than 2cm (the amount of lengthening on the rabbits). 

Their main conclusion does support the idea that slower distraction is better (as long as you don't risk pre consolidation like TRS said).

Agreed, and I actually find the rabbit study very encouraging after making a rough comparison between rabbit and human lengthening.

For the sake of the argument, assume that human and rabbit muscle cells are the same size and have the same tolerance for stretching. Also, the human tibia is roughly 4 times the length of the rabbit tibia lengthened in the study.

The study says the rabbit muscles on the lengthened limb weren't damaged when lengthened at 0.4 mm per day.  Given the assumptions above, you could lengthen 1.6 mm (since the human tibia is 4 x longer) safely.

Think of it this way, if the rabbit muscle is composed of 10 cells, then lengthening 0.4 mm per day would stretch each individual cell 0.04 mm.  If stretching each cell that much is safe, then a human muscle containing four times as many cells (40) could be lengthened 1.6 mm per day, which would stretch each cell the same 0.04 mm as the rabbit.

Obviously, it's not that simple since the assumptions made don't perfectly reflect reality, but it's a good indication that lengthening 1 mm per day or less in humans is safe.  The rabbit study also examined the muscles right after lengthening, which does not consider the body's ability to repair the damage over time.

The main takeaway is that the less you stress your muscles during lengthening, the less they will be damaged. To accomplish that:
1. Stretch and improve flexibility as much as possible before surgery (you're basically pre-lengthening your muscles to give them a head start)
2. Distract lower total daily amounts
3. Distract in multiple small increments per day instead of all at once

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Quote from: JConnor on March 18, 2016, 05:54:02 PMAgreed, and I actually find the rabbit study very encouraging after making a rough comparison between rabbit and human lengthening.

For the sake of the argument, assume that human and rabbit muscle cells are the same size and have the same tolerance for stretching. Also, the human tibia is roughly 4 times the length of the rabbit tibia lengthened in the study.

The study says the rabbit muscles on the lengthened limb weren't damaged when lengthened at 0.4 mm per day.  Given the assumptions above, you could lengthen 1.6 mm (since the human tibia is 4 x longer) safely.

Think of it this way, if the rabbit muscle is composed of 10 cells, then lengthening 0.4 mm per day would stretch each individual cell 0.04 mm.  If stretching each cell that much is safe, then a human muscle containing four times as many cells (40) could be lengthened 1.6 mm per day, which would stretch each cell the same 0.04 mm as the rabbit.

Obviously, it's not that simple since the assumptions made don't perfectly reflect reality, but it's a good indication that lengthening 1 mm per day or less in humans is safe.  The rabbit study also examined the muscles right after lengthening, which does not consider the body's ability to repair the damage over time.

The main takeaway is that the less you stress your muscles during lengthening, the less they will be damaged. To accomplish that:
1. Stretch and improve flexibility as much as possible before surgery (you're basically pre-lengthening your muscles to give them a head start)
2. Distract lower total daily amounts
3. Distract in multiple small increments per day instead of all at once

There is one big flaw with your logic though... Human cells arent bigger than rabbit cells... Just like elefant cells arent bigger than human cells.. Thus the damage to a single cell would be the same. It also depends on the sarcomer length (the "muscle functional unit").
 The only difference between humans, rabbits and elefants is the numebr of cells but not the size

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Another one on goats

http://www.ncbi.nlm.nih.gov/pubmed/12218494

Here is research was done with daily 0.75mm distraction. What's fascinating is that the results showed that the muscle is adapting not by stretching the already existing sarcomeres but by actually adding adittional sarcomers... I can only describe this as another proof of how our body is a marvalous machine

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And here is one on HUMANS. 3 acondroplastics so not normal cases..

 To be noted that the distraction was of 1mm a day (4 times a day of 0.25mm every 6 hours) for a total elongation of 10cm.

Result show alot of muscle damage and poor adaptation (as opposed to what was seen in the goats)

http://www.bio.unipd.it/bam/PDF/5-2/Scelsi.pdf