Limb Lengthening Forum

Please login or register.

Login with username, password and session length
Advanced search  
Pages: [1]   Go Down

Author Topic: Do you get all the cm lenghtened on femurs?  (Read 2463 times)

0 Members and 1 Guest are viewing this topic.

V21

  • Sr. Member
  • ***
  • Offline Offline
  • Posts: 423
Do you get all the cm lenghtened on femurs?
« on: April 08, 2021, 12:29:04 PM »

Hey guys,
Giotikas told me that sometimes, because of the femurs not being straight, you can "lose" like 1 mm per cm. For example, a 6 cm lenghtening would equal to 5.4 real cm. I have seen some guys experiencing this, while others do get the full amount. Has anyone measured precisely in order to detect how must you "lose"? I want to get 5 real cm, so I think I will do 5.5, but I'm still worried about it.
Logged

Body Builder

  • Sr. Member
  • ***
  • Offline Offline
  • Posts: 1950
Re: Do you get all the cm lenghtened on femurs?
« Reply #1 on: April 08, 2021, 02:46:20 PM »

Femurs are slightly curver so yes, it is almost impossible tonget the full amoung lengthened.
Giotikas is right.

For your situation, better do close 6cm to be sure. It is a relatively safe amount after all.
Logged

Dionysus

  • Visitor
  • Offline Offline
  • Posts: 22
Re: Do you get all the cm lenghtened on femurs?
« Reply #2 on: April 08, 2021, 02:51:48 PM »

Let’s say femur is 10% degrees tilted from normal (tibia), cos(10) * 5 =4.92

From my calculations there should be almost no lose.Maybe I am wrong..
Logged

V21

  • Sr. Member
  • ***
  • Offline Offline
  • Posts: 423
Re: Do you get all the cm lenghtened on femurs?
« Reply #3 on: April 08, 2021, 03:40:01 PM »

Let’s say femur is 10% degrees tilted from normal (tibia), cos(10) * 5 =4.92

From my calculations there should be almost no lose.Maybe I am wrong..
Yeah, that's why I ask for "empirical" evidence from people who do get measure. Some seem to lose a bit, and others don't. It's weird. Since I do Precise, I wont be able to measure properly during lenghtening. I think I will do it lying on the floor before surgery, and then again when I'm at 5.5. If there is a 5 cm difference, that's it for me.
Logged

Dionysus

  • Visitor
  • Offline Offline
  • Posts: 22
Re: Do you get all the cm lenghtened on femurs?
« Reply #4 on: April 08, 2021, 03:42:03 PM »

Don’t worry you can measure your height during lengthening.You will be on walker if you are doing precise with bigger nails.I am on walker now.
Logged

BelowTheMean

  • Sr. Member
  • ***
  • Offline Offline
  • Posts: 573
Re: Do you get all the cm lenghtened on femurs?
« Reply #5 on: April 08, 2021, 04:02:01 PM »

Yeah, that's why I ask for "empirical" evidence from people who do get measure. Some seem to lose a bit, and others don't. It's weird. Since I do Precise, I wont be able to measure properly during lenghtening. I think I will do it lying on the floor before surgery, and then again when I'm at 5.5. If there is a 5 cm difference, that's it for me.

Honestly, I can say it's very difficult to measure. You have to consider the compression of the spine at different point in the day, any major APT (duck-ass) that you gained during lengthening that you could fix later on, any discrepancies between the limbs, etc.

Additionally, even when measuring the length of the nail on an X-ray there is a margin of error. Unfortunately the tools to measure height during lengthening just aren't accurate enough. I do believe that almost anyone who lengthens will eventually notice their new height as they grow and reach a point where they are happy with the progress they've made on the nail.
Logged
Stryde Femurs - Debiparshad - Nov 2020
Nail Removal - Downey - Apr 2022
Journal (169cm -> 177cm) http://www.limblengtheningforum.com/index.php?topic=65617

Current Status: Recovered, moving on

V21

  • Sr. Member
  • ***
  • Offline Offline
  • Posts: 423
Re: Do you get all the cm lenghtened on femurs?
« Reply #6 on: April 08, 2021, 04:55:31 PM »

Don’t worry you can measure your height during lengthening.You will be on walker if you are doing precise with bigger nails.I am on walker now.
Yeah, but one thing is using walker and another to measure properly. I think I would not be able to keep perfect posture for measuring like I do now. In order to avoid problems, I do measure only at night, at my "lowest".
Logged

Serilium

  • Sr. Member
  • ***
  • Offline Offline
  • Posts: 352
Re: Do you get all the cm lenghtened on femurs?
« Reply #7 on: April 08, 2021, 05:51:40 PM »

As Dionysus said, the real gain would be that trig formula.

The real real gain is also  essentially dependent on if your doctor knows how to use the magnification feature on the x-ray and measure accurately and consistently (same distance from x-ray machien to leg, or use a comparison next to leg), then take that figure and apply the trig formula after with whatever angle your doctor said or use eos full leg scan to see the angle
Logged

Tartar

  • Full Member
  • **
  • Offline Offline
  • Posts: 287
Re: Do you get all the cm lenghtened on femurs?
« Reply #8 on: April 08, 2021, 06:15:05 PM »

Let’s say femur is 10% degrees tilted from normal (tibia), cos(10) * 5 =4.92

From my calculations there should be almost no lose.Maybe I am wrong..
You are right. The lose is minimal, around 0,5%, let’s say 1% to exaggerate. Still irrelevant.
Logged

Worzezterlire

  • Full Member
  • **
  • Offline Offline
  • Gender: Male
  • Posts: 296
Re: Do you get all the cm lenghtened on femurs?
« Reply #9 on: April 08, 2021, 06:30:11 PM »

I asked Paley this in person and he stated that it is virtually 1:1.  If you lengthen 8cm, you will get 8cm in length.  If less, it’s at most a millimeter or two.  The femurs are at an angle but they are straight if you view them from the side.
Logged

Serilium

  • Sr. Member
  • ***
  • Offline Offline
  • Posts: 352
Re: Do you get all the cm lenghtened on femurs?
« Reply #10 on: April 08, 2021, 06:37:40 PM »

Agree with the opinions here. Just look at a femur x-ray. It almost is straight. It is negligible angle in terms of height loss

Mister v21, I figure doing 5.1cm is enough. 5.2cm if you're worried. 5.5 is not necessary. The more important part is pushing your doctor to accurately measure and check if they are using the proper magnification function and accurate for x-ray measure
Logged

V21

  • Sr. Member
  • ***
  • Offline Offline
  • Posts: 423
Re: Do you get all the cm lenghtened on femurs?
« Reply #11 on: April 08, 2021, 06:48:17 PM »

I agree with all of you that, in theory, the difference should be irrelevant. However there are users who have noticed this. Maybe I'm wrong, but I think that SNC did 8 and, when measured, had 7.3. That's why I'm curious if someone has really measured properly. In the past I have measured obsessively, to the milimitre, and always at my lowest, so I think I will be able to check this in an "empirical" way lol
Logged

Serilium

  • Sr. Member
  • ***
  • Offline Offline
  • Posts: 352
Re: Do you get all the cm lenghtened on femurs?
« Reply #12 on: April 08, 2021, 07:09:33 PM »

Measuring during the day (referring to entire day, not morning) is so variable. Even using night height is so variable. Waking up at 8am and measuring at 9am will be different from 10am, 1 addittional hour, and measuring at night at 8pm will be different from 12pm, and depends how much of day you stood and walked, layed down for 30 minutes or not, etc
Point is, measuring your stature is not reliable if you want it down to the mm

even the magnification adjusted xray can be wrong and probably not accurate to the millimeter

in the end, i think the only surefire way to measure accuracy to the mm is the max out your nail to 8cm according to erc, then keep running it for extra day or a week despite being 8cm, keep going EVEN while its technically 8cm on erc already, keep going, maxing out the nail will be exactly 80mm.

Or better yet, no need to worry for a few decimals of mm.  no one can tell it will just be a personal neurotic thought
Logged

RealLostSoul

  • Sr. Member
  • ***
  • Offline Offline
  • Posts: 567
Re: Do you get all the cm lenghtened on femurs?
« Reply #13 on: April 08, 2021, 07:31:11 PM »

Measuring during the day (referring to entire day, not morning) is so variable. Even using night height is so variable. Waking up at 8am and measuring at 9am will be different from 10am, 1 addittional hour, and measuring at night at 8pm will be different from 12pm, and depends how much of day you stood and walked, layed down for 30 minutes or not, etc
Point is, measuring your stature is not reliable if you want it down to the mm

even the magnification adjusted xray can be wrong and probably not accurate to the millimeter

in the end, i think the only surefire way to measure accuracy to the mm is the max out your nail to 8cm according to erc, then keep running it for extra day or a week despite being 8cm, keep going EVEN while its technically 8cm on erc already, keep going, maxing out the nail will be exactly 80mm.

Or better yet, no need to worry for a few decimals of mm.  no one can tell it will just be a personal neurotic thought

This is the truth. No one measures to the mm in height. Most people when asked lie about their height anyways. Usually they add 2-3 cm on top of it.  inches are way larger so fluctuation during the day are not so relevant if you state your height in feet.

Even different hair can make up a few mm lol
Logged

V21

  • Sr. Member
  • ***
  • Offline Offline
  • Posts: 423
Re: Do you get all the cm lenghtened on femurs?
« Reply #14 on: April 08, 2021, 07:44:18 PM »

Measuring during the day (referring to entire day, not morning) is so variable. Even using night height is so variable. Waking up at 8am and measuring at 9am will be different from 10am, 1 addittional hour, and measuring at night at 8pm will be different from 12pm, and depends how much of day you stood and walked, layed down for 30 minutes or not, etc
Point is, measuring your stature is not reliable if you want it down to the mm

even the magnification adjusted xray can be wrong and probably not accurate to the millimeter

in the end, i think the only surefire way to measure accuracy to the mm is the max out your nail to 8cm according to erc, then keep running it for extra day or a week despite being 8cm, keep going EVEN while its technically 8cm on erc already, keep going, maxing out the nail will be exactly 80mm.

Or better yet, no need to worry for a few decimals of mm.  no one can tell it will just be a personal neurotic thought
I do agree. The issue is that I do this for neurotic reasons hahahaha I do can meausure my lowest. When I measure at night I'm 172.1. After measuring like 4-5 times it goes down to 171.7, but never less than that
Logged

chasing_higher_dream

  • Newbie
  • Offline Offline
  • Gender: Male
  • Posts: 98
  • Life is what you make it
Re: Do you get all the cm lenghtened on femurs?
« Reply #15 on: April 08, 2021, 09:27:26 PM »

Let’s say femur is 10% degrees tilted from normal (tibia), cos(10) * 5 =4.92

From my calculations there should be almost no lose.Maybe I am wrong..
I just googled cos(10) * 5 cm, it shows result as 4.2 cm approximately. You lose almost 0.8 cm for 5cm of lengthening on femur for an angle of 10 degrees between femur and the mechanical axis. Ofcourse, this loss is highly individual and is greatly affected by the angle mentioned.
Do let me know, if you think if there is an issue with the above calculation.

I asked Paley this in person and he stated that it is virtually 1:1.  If you lengthen 8cm, you will get 8cm in length.  If less, it’s at most a millimeter or two.  The femurs are at an angle but they are straight if you view them from the side.
Ofcourse the femur bone would look straight from the side view, but from the frontal view its not! Mathematically speaking you would never get 1:1 of the increased length. i.e. If you lengthen 8 cm in femurs, the original height increase will always be less than 8cm.


It would be great to have some practical insights from people who have already done limb lengthening on their femurs.
« Last Edit: April 08, 2021, 10:21:36 PM by chasing_higher_dream »
Logged
Femurs with Dr. Betz - May 2021
Height (night):  170 cm --> 178 cm
Wingspan: 174 cm
Age: 29
Diary: http://www.limblengtheningforum.com/index.php?topic=66215.0

Serilium

  • Sr. Member
  • ***
  • Offline Offline
  • Posts: 352
Re: Do you get all the cm lenghtened on femurs?
« Reply #16 on: April 08, 2021, 10:23:36 PM »

Big issue. Google on default uses radians instead of degrees. You need cos(10degrees).
Logged

chasing_higher_dream

  • Newbie
  • Offline Offline
  • Gender: Male
  • Posts: 98
  • Life is what you make it
Re: Do you get all the cm lenghtened on femurs?
« Reply #17 on: April 08, 2021, 10:28:12 PM »

Big issue. Google on default uses radians instead of degrees. You need cos(10degrees).

Thanks for the correction, Serilium.
Indeed, cos(10 degrees) * 5 cm =4.92 cm.

The loss is almost 0.08 cm for 5cm of femoral lengthening, which is negligible.
Logged
Femurs with Dr. Betz - May 2021
Height (night):  170 cm --> 178 cm
Wingspan: 174 cm
Age: 29
Diary: http://www.limblengtheningforum.com/index.php?topic=66215.0

Ahd1978

  • Newbie
  • Offline Offline
  • Posts: 71
Re: Do you get all the cm lenghtened on femurs?
« Reply #18 on: April 09, 2021, 11:17:43 PM »

Hi guys

3 weeks ago I reached 4 cm distraction in x ray

My starting height was 176.5 cm. I directly wen to measure and was spot on 180.5 cm

Since then did my x rays again and 5.8 cm lengthened in x ray so technically should have measured at 182.3.

However I measured at 181.5

So I don’t get it how x ray height shows 5.8 cm lengthened but only 5 cm jn real measurement.

Maybe first time I measured it was morning height and now I measured afternoon.

Still boggles me.

Some have advised me poor posture could affect and eventually I will see full height gain

Any comments
Logged

Worzezterlire

  • Full Member
  • **
  • Offline Offline
  • Gender: Male
  • Posts: 296
Re: Do you get all the cm lenghtened on femurs?
« Reply #19 on: April 10, 2021, 01:16:57 AM »

I just googled cos(10) * 5 cm, it shows result as 4.2 cm approximately. You lose almost 0.8 cm for 5cm of lengthening on femur for an angle of 10 degrees between femur and the mechanical axis. Ofcourse, this loss is highly individual and is greatly affected by the angle mentioned.
Do let me know, if you think if there is an issue with the above calculation.
Ofcourse the femur bone would look straight from the side view, but from the frontal view its not! Mathematically speaking you would never get 1:1 of the increased length. i.e. If you lengthen 8 cm in femurs, the original height increase will always be less than 8cm.


It would be great to have some practical insights from people who have already done limb lengthening on their femurs.

When you googled cos(10), you were not googling cos(10 degrees).  Default google unit is radians.

5cm * cos(10 degrees) is 4.92cm.

I think this is why paley told me that you get exactly what you lengthen.  Even at his limit of 8cm for femurs that is just over a millimeter “lost” or less than 2% of total length.  You probably lose more than that within the first 5 minutes of waking up.

Hi guys

3 weeks ago I reached 4 cm distraction in x ray

My starting height was 176.5 cm. I directly wen to measure and was spot on 180.5 cm

Since then did my x rays again and 5.8 cm lengthened in x ray so technically should have measured at 182.3.

However I measured at 181.5

So I don’t get it how x ray height shows 5.8 cm lengthened but only 5 cm jn real measurement.

Maybe first time I measured it was morning height and now I measured afternoon.

Still boggles me.

Some have advised me poor posture could affect and eventually I will see full height gain

Any comments

Honestly unless you measured at the same time of day (hours since bed) and posture with the same measuring method then it’s really hard to say anything other than to go back and make sure you measured at the same time of day and in the same posture and with the same measuring apparatus.
Logged

Ahd1978

  • Newbie
  • Offline Offline
  • Posts: 71
Re: Do you get all the cm lenghtened on femurs?
« Reply #20 on: April 10, 2021, 05:19:29 PM »

Thanks

Yes that was early morning.

All other times have measured jn afternoon

Same measuring apparatus.

Looking to get in early one day and measure height in morning hours and see.

Towards 6 cm and sitting on bed posture might lose few mm

Have started to hang from pull up bar to straighten back

Will revert with results over next 2 weeks

Logged

sixfootandhalf

  • Jr. Member
  • *
  • Offline Offline
  • Posts: 181
Re: Do you get all the cm lenghtened on femurs?
« Reply #21 on: October 11, 2022, 04:43:35 AM »

Negligible i think
Logged
Current height: 174.5cm  evening (175.3m left leg 174.5 left leg). Lengthening: 7cm
Final height 182-183cm afternoon height with glucosamine, stretching and posture.
Pages: [1]   Go Up