Questions tagged [bio-mechanics]

The study biological systems in regards to their ability to apply and respond to mechanical forces.

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Why do wasps have "wasp waists"? What's been optimized?

I photographed these (unidentified) wasps on a sunny but cool winter day in northern Taiwan because they were conspicuously hanging out on a hand railing and had much lighter coloring than I'd ever ...
uhoh's user avatar
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20 votes
1 answer
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How did the largest/longest dinosaurs hold their head and necks up?

After seeing the images in the articles shown below, I am having a tough time understanding the mechanics of how these incredibly long and heavy necks can be supported outstretched like this. A rigid ...
uhoh's user avatar
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18 votes
1 answer
4k views

How fast can a human run?

I'm a runner (cross country) and I'm always amazed at how fast Olympic sprinters are. There's a lot of hype about those in the 100-meter dash being the fastest in the world, and we're constantly ...
HDE 226868's user avatar
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11 votes
1 answer
40k views

How do disulphide bonds in hair cause curling?

I understand that there are several characteristics of curly hair which differ from straight hair (such as an asymmetrical distribution of disulphide bonds in curly hair), but really am struggling to ...
User2341's user avatar
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9 votes
2 answers
13k views

How do marine mammals control buoyancy?

Presumably, as a whale or seal dives, its lungs get compressed by the increasing water pressure, and it gets less buoyant. Under this model, for a given amount of air taken in at the surface, the ...
SuperElectric's user avatar
8 votes
2 answers
2k views

Which part of human body sustains most pressure when standing up straight?

Let's suppose a healthy fit barefoot young adult standing comfortably on a flat solid surface. A reasonable guess is somewhere around the foot. But is it the ankle, the heel, or the Metatarsus?
Grigori Sun's user avatar
6 votes
1 answer
209 views

How is a synapse held in place?

Here is a question I've never asked myself until now: All textbooks show synapses with a decently large synaptic cleft between the axon terminal and the dendrite. How is this connection held in place ...
Moppentapper's user avatar
5 votes
1 answer
154 views

Why do flagella form a bundle only when they rotate counterclockwise during chemotaxis?

During Chemotaxis in bacteria with flagella, the flagellar rotation dictates how the cell moves. If the flagella rotate counterclockwise, then they form a bundle at one end of the cell (---O) and ...
BluWasabi's user avatar
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5 votes
0 answers
62 views

How does trees know to balance themselves so that they never fall down [duplicate]

Well i was flying kites today I saw a tree and its branches were spread around in random directions... I would like to know that how do these trees know to nourish their branches in some direction so ...
Jasser's user avatar
  • 149
4 votes
2 answers
2k views

What are the buoyancy control mechanisms of Chambered nautilus?

I'm currently working on an underwater robot and was hoping to use the principle used by the nautilus for buoyancy control. So how do the Chambered nautilus control its buoyancy?
user8697's user avatar
4 votes
0 answers
379 views

How can skeletal muscles in the human body be modeled as levers? [closed]

From what I understand, human arms can be thought of as third class levers, so that the distance from your elbow to the place where the muscle attaches is effectively the distance to the fulcrum, so ...
Tom's user avatar
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3 votes
3 answers
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Any simulations of four-winged dinosaur flight? (microraptors)

This week's podcast of the BBC's Science in Action includes a section by Rory Galloway (12:20 to 18:30) covering the Dinosaurs ...
uhoh's user avatar
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3 votes
2 answers
5k views

Highest bite force of a wolf?

Some sites say wolves can bite around 400 psi. But this site claims that when facing a peril they can deliver upto 1200 ?https://plexidors.com/myths-around-dog-bite-force/(skip to the 'How does that ...
Specter's user avatar
  • 31
3 votes
1 answer
945 views

Can geckos climb a wet surface?

We know geckos can climb vertically or even upside down a surface like glass. But can they do that on wet glass?
sloupioc's user avatar
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3 votes
1 answer
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Why do we have the tibia and fibula (a 2nd bone) in the lower leg?

Does fibula participate in rotational movement of ankle or not (just like the radius in forearm)? If not, what is the purpose of that bone?
Gleb Voronchikhin's user avatar
3 votes
0 answers
44 views

Mechanics of Peregrine Falcon Dive Pull Up

There are loads of information on how fast the Peregrine Falcon dives, but aside from having specialized lungs, eyes, etc... to survive the dive. What mechanics does it use to pull out of such a dive,...
Last's user avatar
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2 votes
2 answers
605 views

Why does resting potential not become continually more negative?

(Firstly, I know this is similar to other questions, but I have read those answers and they do not really cover this topic). My understanding of resting potential: action potential is not being ...
Ben Hughes's user avatar
2 votes
1 answer
127 views

Biomechanics of cells (stress, strain, tension..)

I am confused about the difference between stress, strain, tension, pre-strain and prestress in cells (especially in in-vitro experiments, like cell spreading on a substrate, cell doublets, cell ...
Remember's user avatar
  • 193
2 votes
1 answer
1k views

How fast is the patellar reflex?

I have found a lot of content on the patellar reflex, but I cannot find any studies on how fast the reflex is, from onset of stimulus to innervation of muscles. Does anyone know of either a study or ...
Cort Ammon's user avatar
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2 votes
1 answer
189 views

How do proteins perform their function [closed]

I have asked a question on physics stackexchange, but was redirected here. I copy the entire question word for word. The original is here. Let's, for example, take a ribosome. It is an enzyme that is ...
Anton's user avatar
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2 votes
1 answer
417 views

Reference for the bite force for Nile Crocodile

The (maximal) bite force of the Nile Crocodile (Crocodylus niloticus) is estimated around 22,000 Newton (refer to YouTube interview with Ofer Kobi, a crocodile conservation ranger and croc farm owner, ...
Triceratops's user avatar
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2 votes
1 answer
138 views

Are there biological ratchet cycles that are small in number?

I recently came across the strange factoid that all animals that can jump do so to roughly the same height (within an order of magnitude). The argument was that the work done by muscles in a single ...
Cort Ammon's user avatar
  • 1,364
2 votes
0 answers
96 views

Calculate radius of curvature of DNA

I am using this article to calculate the radius of curvature of DNA. I know that 150bp segment of DNA length wraps itself 1.7 times around a histone core. There are 0.34nm/bp DNA's persistence length ...
Monya Feldman's user avatar
2 votes
0 answers
20 views

The exact points of muscle attachment and the "equal and opposite force" that skeletal muscles apply

I've been trying to make a simple simulation of the human body executing some motions in Mathematica (the details are irrelevant), but I need to know some more information about muscles and how they ...
Pineapple Fish's user avatar
2 votes
0 answers
55 views

why does water go from high to low osmotic pressure to decrease the size of the nucleus?

I am reading this paper "Volume regulation and shape bifurcation in the cell nucleus" (linked below) https://jcs.biologists.org/content/joces/128/18/3375.full.pdf I am confused by this ...
veraxxarev's user avatar
2 votes
0 answers
39 views

Do tarantulas and humans have the same mechanism for growing hair?

There's hair on my arms. Tarantulas also have hair on their arms. Is this the same type of hair?
OregonTrail's user avatar
2 votes
0 answers
41 views

How does anaerobic burst-flight performance scale with mass?

Quails employ anaerobic burst flight to escape predators and the Quetzalcoatlus northropi have most likely used it during launch and climb out, then transition to soaring. Now, I have read these ...
Mephistopheles's user avatar
2 votes
0 answers
35 views

How does fungi network transfer substances between plants?

How does fungi network transfer substances between plants? I recently read a short article about fungi network. And I am wondering about how fungi network works (Mechanism). Plants have fungi ...
KYHSGeekCode's user avatar
2 votes
0 answers
52 views

Are trees still carrying their leaves more likely to be felled by an autumn storm?

Is there evidence that trees still carrying their leaves are more likely to be felled by an autumn storm than trees already having lost their leaves? At first sight this seems plausible (and might be ...
Hans-Peter Stricker's user avatar
2 votes
0 answers
94 views

force required to do damage to child's leg/feet in collision [closed]

I'm currently working on a toy robot for a student project. Part of this robot is the fact that it will be moving around quite fast. As such hitting the child can and most likely will happen. As such ...
Thijser's user avatar
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1 vote
2 answers
4k views

Are there any predators without camouflage?

Are there any predators that don't use camouflage?
DigitalRookie's user avatar
1 vote
2 answers
39 views

In human anatomy / biomechanics, what is the motion called when the arm swings sideways so the elbow moves in an arc of 90 degrees?

In human anatomy / biomechanics, what is the motion called when the arm swings sideways so the elbow moves in an arc of 90 degrees? So e.g. if a person was to elbow somebody behind them , or if ...
barlop's user avatar
  • 735
1 vote
1 answer
521 views

What is the acceleration profile of the greyhound?

I'm interested in the acceleration curve over time that's typical of an adult greyhound prior to attaining this peak velocity. My curiosity is motivated by a desire to understand the biomechanical ...
Aidan Rocke's user avatar
1 vote
1 answer
47 views

What’s the term used to define a terrestrial being that moves by using six limbs?

I know that Bipedal locomotion would describe how beings like humans and ostriches get around. Quadrupedal locomotion describes how beings like dogs and cats move around. What about insects, ...
Iam Pyre's user avatar
  • 113
1 vote
1 answer
700 views

What is the purpose of the viscous gel in the Pacinian corpuscle?

I have read that 'when the stimulus (in this case pressure) is constantly applied, the gel repositions itself to prevent the formation of an action potential'. I don't really understand what this ...
Stephen Gevanni's user avatar
1 vote
0 answers
22 views

Movement of the Ribcage during movements of the Thoracic Spine

I want to find a rough relation between the angle of rotation of the thoracic spine and the corresponding segmental movements in the skeleton of the ribcage. I have come across some research which ...
Prakhar's user avatar
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1 vote
0 answers
201 views

Biological reason for "deadlift face"?

Always when I deadlift at the maximum load, my face looks more or less like this: or this: The same applies for when I do other heavy-weight exercises. But what biological mechanism causes that? ...
user46147's user avatar
  • 295
1 vote
0 answers
14 views

Actin-myosin cortex stiffness VS elasticity

I have two questions on the mechanics of actin-myosin network: 1- Actomyosin cortex as an elastic material is defined by its elastic modulus $E$. But I know that elasticity would be described by the ...
Remember's user avatar
  • 193
1 vote
0 answers
38 views

Question about the basilar membrane mechanics (cochlea)

I am reading about the mechanics of the basilar membrane in the inner ear. In various publications, it is said that, at a specific position on the basilar membrane, the outer hair cells are activated ...
Marina's user avatar
  • 39
1 vote
2 answers
122 views

Why does the gravity of Earth appear in this formula estimating speed?

I'm currently reading the wonderful book The Dinosaurs Rediscovered by Michael J. Benton. It contains the formula $$v = 0.25 * g^{0.5} * SL^{1.67} * h^{-1.17}$$ where $v$ denotes velocity, $SL$ is ...
Joseph Doob's user avatar
1 vote
0 answers
60 views

Origins of the body mechanics theory

In physical therapy and occasionally in sports coaching, there's often a precise description of the mechanics of what happens during the movement (which muscles are engaged, which joint moves where ...
Athere's user avatar
  • 41
1 vote
0 answers
386 views

Movement of the Thoracic Cage During Movements of the Thoracic Spine

Just for a bit of context: I am trying to create a 3D digital model of the human skeleton as the first step towards computer generated muscle simulation, and as such I want the skeleton to be as ...
Robert Gregson's user avatar
1 vote
0 answers
97 views

Tensile strength of collagen?

Really specific question, but what is the average tensile strength of human collagen, type I? I've tried looking for it online, and either my google-fu skills are weak, or I'm just unlucky. Also, is ...
tox123's user avatar
  • 508
1 vote
0 answers
40 views

about the muscle's tension's variables

I'm reading the paper "THE PROBLEM OF THE INTERRELATION OF CO-ORDINATION AND LOCALIZATION", which is written by N. Bernstein. The paper said "The degree of tension of a muscle is a function, in the ...
Kim Jaewoo's user avatar
1 vote
1 answer
18 views

How are the helices of MscL gating "attached"?

I'm attempting to model the mechanosensitive channels of large conductance (MscL) in E. coli for finite element analysis purposes. I have a number of papers where this has been done, and one shows the ...
Asinine's user avatar
  • 13
1 vote
0 answers
889 views

Strongest bone in body

AS internet tells is it is thigh bone which is strongest, but why, it carry only upper part of body, does not heel or any foot bones should be strongest in body as they carry full body weight ?
murmansk's user avatar
  • 1,807
1 vote
0 answers
36 views

Muscle involved in carrying load on head

I have seen people carrying heavy load on their head especially in 3rd world countries, does carrying on head any benefit or harm, which muscle get strengthen in doing it?
murmansk's user avatar
  • 1,807
1 vote
0 answers
999 views

Three foramen lying in one vertical plane

In the human skull we can see that 3 foramina named as supraorbital notch(foramen) , infraorbital foramen and mental foramen share a common vertical plane. Is there any surgical significance of for ...
JM97's user avatar
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1 vote
0 answers
389 views

How is the Force of Contraction Applied to the Tendons by the Muscle's Individual Fibers?

Image and question have been updated for clarity! The image above is a side view of a semi-transparent skeletal muscle. The dark red lines represent individual fibers, the blue lines represent ...
Jon Yang's user avatar
0 votes
1 answer
267 views

Does the human abdominal cavity use pressure to maintain posture?

Several of my PT friends have referenced a physical therapist p who has studied breathing named Mary Massery. In her articles, she has referenced the idea of "intra-abdominal pressure" http://www....
Stan Shunpike's user avatar