Compressive force of a shorter cylindrical bone vs a longer one

[A.T.]

If we can't use the maximum compressive breaking load of bones alone and want to make hypothetical assumptions, what is the definitive force of the strongest ever kick or punch?

Not in a simple way. You would need a mechanical musculoskeletal model, with a very high temporal resolution to capture the high impact accelerations, which also takes the inertia of the body segments into account.

Also note that the individual strength of bones can vary a lot, because bones adapt to the loading they experience. Athletes and and people doing martial arts can have much stronger bones than the values for the general population that you might find in references.

 

[Rev. Cheeseman]

Not in a simple way. You would need a mechanical musculoskeletal model, with a very high temporal resolution to capture the high impact accelerations, which also takes the inertia of the body segments into account.

Also note that the individual strength of bones can vary a lot, because bones adapt to the loading they experience. Athletes and and people doing martial arts can have much stronger bones than the values for the general population that you might find in references.

Ok, I can't understand the point of this statement. What does "The momentum of the hand or foot, can apply an impulse greater than the compressive strength of the leg or arm bones. It is maintaining a steady force that tests the bone. It will also depend on whether an injury is acceptable" means? Sorry, my English comprehension is bad.

 

[A.T.]

Ok, I can't understand the point of this statement. What does "The momentum of the hand or foot, can apply an impulse greater than the compressive strength of the leg or arm bones. It is maintaining a steady force that tests the bone. It will also depend on whether an injury is acceptable" means?

The steady force application to static bones in the tests is different from briefly acting impact force peaks at the foot. The brief impact force must also account for the acceleration of shank and foot, rather than just for compressing the femur.

 

[Rev. Cheeseman]

Rev. Cheeseman said

Hello, is this https://efficientengineer.com/buckling-calculator/ a good calculator for measuring the compressive force between a longer bone and a shorter bone with the same diameter or circumference?

 

[Rev. Cheeseman]

Baluncore said


No.
Buckling occurs with longer columns, with lengths over 30 times the diameter. Bones are not long enough to fit that model, especially when your test sample examples have diameter to length less than about 1 : 2.

Your problem is more like sampling. If you have a sample of strength 100±10, then how strong will two be in series 100±?

You have a live thread in the open forum. If you ask there, I will be notified, and others will also see it, and answer, and the forum will get hits from Google etc. That way, others benefit from each answer, which justifies the time needed for good answers.

No one will see this conversation, so it costs me full price, then only you benefit.

 

[Rev. Cheeseman]

A.T. said:


No, because as explained in the thread, the bones are loaded by muscles attaching all over them, not just by two forces at their ends.

 

[Rev. Cheeseman]

According to https://books.google.com.my/books?i...of the femur is defined in FMVSS 208"&f=false, 10000 Newton force for several milliseconds is enough to break a femur from the vertical compression position. Humerus is weaker than femur in terms of vertical compression. Therefore, hypothetically, the strongest possible punch a human can generate is around 2 tonnes in my opinion before the humerus started to break.