- #1
vinny11
- 1
- 0
When kicking off the ground, what is the maximum amount of force that human's can exert?
Any references?
Any references?
Max Force Humans Can Exert When Kicking Off Ground
Click For Summary
Discussion Overview
The discussion revolves around the maximum force that humans can exert when kicking off the ground, with a focus on different interpretations of "kicking" and the mechanics involved in related movements such as high jumping and deadlifting. Participants explore theoretical estimates and the implications of different types of leg movements.
Discussion Character
- Exploratory
- Debate/contested
- Technical explanation
Main Points Raised
- One participant estimates that the maximum force exerted when kicking off the ground could be around 2000N, based on calculations related to high jumping.
- Another participant suggests that the force could be higher, referencing the ability of individuals to deadlift 455kg, which translates to approximately 4500N.
- There is a discussion about the definition of "kicking," with some participants arguing that movements like high jumping and deadlifting should be classified as pushing rather than kicking.
- One participant questions the assumption that high jumpers bend their knees to 90 degrees during takeoff, suggesting that this may affect the calculations of impulse duration.
- Another participant proposes that the duration of force application during a kick may be much shorter than 0.2 seconds, challenging the initial estimates based on that time frame.
- There is a comparison made between kicking a soccer ball and the mechanics of kicking off the ground, with an emphasis on the transfer of momentum.
Areas of Agreement / Disagreement
Participants express differing views on what constitutes "kicking" and how it relates to other movements, indicating that there is no consensus on the definitions or the calculations of force involved.
Contextual Notes
Some assumptions regarding the duration of force application and the mechanics of kicking versus pushing remain unresolved, and the discussion highlights the complexity of defining the movements involved.
- #2
meichenl
- 25
- 0
rough estimate: 2000N
the world high jump record is 2.45m. A good high jumper can actually have his center of mass pass under the bar by arching around it, so say his center of mass rose to 2.40m. The dude who did it is 1.94m tall. The center of mass of a man is about .56 his height (hypertextbook.com/facts/2006/centerofmass.shtml), so that's 1.09m. So he jumped 1.31m. I don't know what he weighed, but 80kg is a reasonable guess. The impulse would have to have been 406 kg*m/s.
To figure out over how long a time that impulse was delivered, imagine he bent his knees to 90 degrees, then straightened them, lifting himself .5m before taking off. If his acceleration was constant in that time, it would have taken him .20 seconds, yielding a force of 2000N.
the world high jump record is 2.45m. A good high jumper can actually have his center of mass pass under the bar by arching around it, so say his center of mass rose to 2.40m. The dude who did it is 1.94m tall. The center of mass of a man is about .56 his height (hypertextbook.com/facts/2006/centerofmass.shtml), so that's 1.09m. So he jumped 1.31m. I don't know what he weighed, but 80kg is a reasonable guess. The impulse would have to have been 406 kg*m/s.
To figure out over how long a time that impulse was delivered, imagine he bent his knees to 90 degrees, then straightened them, lifting himself .5m before taking off. If his acceleration was constant in that time, it would have taken him .20 seconds, yielding a force of 2000N.
- #3
meichenl
- 25
- 0
on second thought, it should be more. people can deadlift 455kg, so that's 4500N right there.
- #4
ddelaiarro
- 41
- 3
What exactly do you mean by kicking?
meichenl gives two examples - a high jumper and a deadlifter. Personally, I'd classify both movements as pushing, not kicking...
meichenl gives two examples - a high jumper and a deadlifter. Personally, I'd classify both movements as pushing, not kicking...
- #5
jbunten
- 86
- 0
ddelaiarro said:
isn't a kick just a type of push?
- #6
ddelaiarro
- 41
- 3
well, I suppose it could be. But, when I 'hear' kick, I thinking of kicking a soccer ball or a football. I think we'd all agree that that movement is different than a pushing type movement...
- #7
jbunten
- 86
- 0
Hmm, In a way I see what you mean. When one kicks a ball properly (football=soccer ball to me I'm afraid) one stops applying force on contact with the ball and let's the transfer of momentum from the foot to the ball move the ball forward. However it really is a very related question.
vinny11 why do you assume he bent his knees to 90 degrees? High jumpers always start with a run so this assumption might be the problem with your calculation i.e I think the actual impulse lasts way less than 0.2 seconds.
check out this guy for instance:
even in slow mo his foot is in contact with the ground for far less than 0.2s.
vinny11 why do you assume he bent his knees to 90 degrees? High jumpers always start with a run so this assumption might be the problem with your calculation i.e I think the actual impulse lasts way less than 0.2 seconds.
check out this guy for instance:
even in slow mo his foot is in contact with the ground for far less than 0.2s.
Last edited by a moderator:
- #8
meichenl
- 25
- 0
jbunten,
maybe it's less than .2 sec, although just by watching the video i can't tell. is there an easy way to count the number of frames it takes him to take off, and divide by the frame rate?
maybe it's less than .2 sec, although just by watching the video i can't tell. is there an easy way to count the number of frames it takes him to take off, and divide by the frame rate?
- #9
DaveC426913
Gold Member
2025 Award
- 24,442
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In fact, it's the same question. Over a duration approaching zero (i.e. before gravity is a significant factor), kicking a soccer ball is the same as kicking off a much much MUCH larger ball.jbunten said:
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