Busy. Please wait.
or

show password
Forgot Password?

Don't have an account?  Sign up 
or

Username is available taken
show password

why


Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account.
We do not share your email address with others. It is only used to allow you to reset your password. For details read our Privacy Policy and Terms of Service.


Already a StudyStack user? Log In

Reset Password
Enter the associated with your account, and we'll email you a link to reset your password.

Remove Ads
Don't know
Know
remaining cards
Save
0:01
To flip the current card, click it or press the Spacebar key.  To move the current card to one of the three colored boxes, click on the box.  You may also press the UP ARROW key to move the card to the "Know" box, the DOWN ARROW key to move the card to the "Don't know" box, or the RIGHT ARROW key to move the card to the Remaining box.  You may also click on the card displayed in any of the three boxes to bring that card back to the center.

Pass complete!

"Know" box contains:
Time elapsed:
Retries:
restart all cards




share
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how

Biomechanics 176

TermDefinition
weight m*g
Shear stress (Andrea) Force applied parallel to area undergoing stress
Tensile Stress (Andrea) Object is being pulled
Yield Stress (Andrea) The point in which hooke's law is no longer obeyed
Stress (Andrea) Force/Area
Speed (Andrea) Distance/Time
Velocity (Andrea) Speed with direction
Acceleration (Andrea) Velocity/Time
Momentum (p) (Andrea) mass(m)/Velocity (v)
Force (F) (Andrea) mass(m)*acceleration (a)
Work (w) (Andrea) force(F) * displacement (s)
Power (Andrea) Force (F) * velocity (v)
Blood Flow (Q) (Andrea) Change in Pressure (^P)/Resistance (R)
Cross Sectional Area (CSA) (Andrea) (muscle mass * Cos theta )/ (Fiber Lenght *muscle density)
Blood Velocity (Andrea) Q/A
Cardiac output (Andrea) Stroke volume (SV) * Heart Rate (HR)
Young's Modulus (Andrea) stress/strain
Isometric Contraction maintains same muscle length during a contraction
Concentric Contraction shortening of muscle during a contraction
Eccentric Contraction lengthening/elongation of muscle during a contraction
Pressure Drag def: force required to move fluid around object/animal Dominates When: - high speed - large size - low viscosity
Friction Drag def: force due to interactions between the fluid and surface of object/animal Dominates When: - low speed - small size - high viscosity
Drag (D) (1/2)*Drag Coefficient(Cd)*density*surface area(SA)*velocity(v)^2
Poiseuille's Equation Volumetric flow(Q)= [change in pressure(deltaP)*pi*radius(r)^4]/[8*length(L)*viscosity)
Vasoconstriction - decrease radius - less flow - increase resistance
Vasodilation - increase radius - more flow - decrease resistance
Lift (L) (1/2)*Lift Coefficient(Cl)*density*surface area(SA)*velocity(v)^2
Clingfish Attaches rough surfaces by: - microscopic hairs - mucus layers - soft rim
stance foot in contact
swing foot in air
Measuring Joint & Muscle Moments muscle moment arm(r)*Muscle force(Fm)=Joint moment arm(R)*Ground Reaction Force(G)
Limb Effective Mechanical Advantage (EMA) Ground Reaction Force (G)/Muscle Force (Fm) ; higher EMA=lower effort, lower EMA= higher effort
viscoelastic resists shear flow and strain linearly with time when a stress is applied; strains when stretched and quickly return to their original state once the stress is removed; therefore exhibits time-dependent strain.
Reynolds Number critical for describing fluid flow; Fi/Fv = inertial forces/viscous forces; high RE, high turbulence, low RE, laminar flow
principle of continuity P1V1=P2V2
Frank-starling law of the heart increase in end-diastolic volume results in a more forceful contraction
Flight and swim rotation pitch = up-and-down "nod" movement; roll = rotation sideways; yaw = sideway movement
Parts of a fish paired fins: pectoral and pelvic fins; median fins: dorsal, caudal, anal fins
Forces on a fish buoyant, thrust, weight, drag
Thrust force change in momentum of vortex/change in time
High aspect ratio longer body, less surface area
Low aspect ratio shorter body, more surface area
BCF (Body/Caudal Fin) periodic propulsion; cyclically repeating kinematics; lower power, sustainable
BCF Transient brief non-repeating kinematics, high power
MPF (Median Paired Fins) brief or long term variable kinematics, high speed low acceleration, feeding motion
Barnacle cement 90% protein, coagulates and polymerizes like blood cots in humans
echinoderms starfish; stick with a 3 part adhesion. two parts are adhesive cells, one part is for detachment
walk inverted pendulum, energy exchange between KE and PE
run exchange between PE and KE, with work and stored energy
Stress scale to mass Stress = F/A = [m^(3/3)]/[m^(2/3)] = m^(1/3)
Ground Reaction Force (GRF) force exerted by the ground back on you; your "weight"
3 ways to contract isometrically (Allen Le) tendon-muscle, biarticular, muscle-muscle
in situ(Allen Le) in place, animal isn't moving
in vivo(Allen Le) in place, animal is moving
in vitro(Allen Le) out of body
sonomicrometry(Allen Le) measuring muscle length change in vivo
newtonian fluid (Allen Le) single value of viscosity, linear relationship b/w applied shear stress and resulting rate of deformation
adhesion(Allen Le) physical attraction or joining of 2 surfaces
two approaches to measure spring mechanism(Allen Le) 1) measure directly (tendon buckles, EMG, sonomicrometry), 2) external analysis (GRF and Kinematics)
vector(Allen Le) magnitude and direction
newton's 3 laws(Allen Le) 1) body stays rest or stays in motion unless force is applied to it 2)F=MA 3)equal and opposite forces
how does length scale with mass(Allen Le) L=M^1/3
how does area scale with mass(Allen Le) A=M^2/3
Efficiency(Allen Le) W in / W out x 100
perfectly elastic(Allen Le) returns to original shape no energy lost
perfectly plastic(Allen Le) doesn't return to original shape, all energy lost
viscoelastic(Allen Le) returns to original shape after some delay, some energy lost
Permanent Adhesion(Allen Le) involves cement
Temporary attachment(Allen Le) allowing animal to attach strongly but detach quickly when it needs
Transitory(Allen Le) Simultaneous attachment and locomotion
Clingfish(Allen Le) microscopic hairs, suction, form a soft rim on surface, and secrete mucus to bind to rough surfaces
Gecko Adhesion(Allen Le) millions of microscopic hairs - use van Der waal's forces. Attaches to smooth surfaces
Turbulence destroys streamlines, high rates of sheer, viscous dissipation of energy
Vortex a packet of spinning fluid, cannot end in open space
Gliding using potential energy to offset drag; animal descends relative to air
Soaring gliding in upwardly moving air. Three kinds: slope soaring, circles to stay in thermal, dynamic soaring
Tip vortex lost energy
Angle of attack angle between airfoil and airfoil axis. If more than 15 degrees, there will be no lift
Thrust the forward component of F_aero
Aspect ratio length^2/surface area length/cord
Wing loading mass/surface area (of wing)
Types of organismal attachment/adhesion 1- Permanent: involves cement 2- Temporary: allows animals to attach strongly but detach quickly 3- Transitory 3- Transitory: simultaneous attachment and locomotion
Geckos (adhesion) microscopic hair made from keratin, van der waals interactions
Muscle moment r x F_m (muscle moment arm x muscle force)
Joint moment R x G (joint moment arm x ground reaction force)
Tipping point Size of Base of Support (BoS)/ height of Center of Mass (CoM)
Autotomy self-amputation of appendages; muscular contractions break vertebrae at autotomy plane
Which Fins prevent Rolling in Fish Median Fins
Which fins prevent Pitching Paired Fins
Which Fins prevents Yawning All fins (Median and paired)`
Digital practical image Velocimetry A device that utilizes a strong beam of laser and silver particles to reflect the formation of vortex in relation to fin movement to understand the biomechanics of swimming.
Thrust force Momentum of vortex/ Time it took to form the vortex
Momentum of vortex water density (rho) *Circulation vortex * A (Surface area of the vortex)(pi*r^2)
Circulation of vortex Avg. Tangential velocity * Circumference (2*pi*r)
Aspect ratio (leading edge)^2/ Area
High aspect ratio fin Long fin and smaller surface area minimal drag long distance swimming because they have longer drag High efficiency
Low aspect ratio fin Short and larger area
C-start Mechanism Mauther cell, 1) pairs of neurons run down each side of the body 2) discharge muscle contraction 3) one side is inhibited 4) C-shape Formed 5) Used in escaping
S-strart Mechanism -prey capture -slower than C-start -More accurate than C-start -simultaneous muscle contraction
Static Stability A vertical line passing through Center of Mass (CoM) will fall within base of support (BoS)
Hydrostatic stability in Fish Fish are always hydrostatically stable becaus ethe use fin muscle to prevent rolling upside down.
Dynamic Stability Active property that always relies on feedback to bring back the animal to normal movement after perturbation.
Joint Flexor Moment When the angle of the joint is below 180 degrees on the side facing the Ground Reaction Force
Permanent Organismal Attachment Involves cement
Temporary Organismal Attachment Allowing animal to attach strongly, but detach quickly
Transitory Organismal Attachment Simultaneous attachment + locomotion
Static Stability Passive property; forces acting on body are at equilibrium. Based on the location of the center of mass relative to base of support.
Tipping Point Size of base of support/center of mass
Dynamic Stability Active property; relies on constant feedback, sometimes feet forward control
Robustness Max perturbation that an animal can handle
Tail Stability Can be used for climbing, mid-air righting, and jumping
Centripetal Force mv^2/r
Muscle Moment r*Fm
Joint Moment R*G
Joint Extensor Moment When the angle of the joint is above 180 degrees on the side facing the Ground Reaction Force
Compressive Stress Force is perpendicular to the area acted upon, and acts to 'squeeze' the surface
Flexural Stress Force acts to 'bend' the material, and combines shear, tensile and compressive stresses
Torsional Stress Force acts to 'twist' the material. Multiple stresses involved
Pressure Force over area, acts omnidirectional
Potential Energy Energy due to an object's position in space. (mass) x (acceleration due to gravity) x (height)
Kinetic Energy Energy due to an object's velocity. (mass) x (velocity)^2 x (1/2)
Conservation of Energy Total energy in a system is constant. This does not preclude the energy from changing forms (eg. potential energy can become kinetic energy)
Conservation of Momentum Momentum is constant for an object. (mass) x (velocity)
Higher Effective Mechanical Advantage lower effort
Lower Effective Mechanical Advantage higher effort
Change in Elastic Storage Change in Kinetic energy + Change in Potential energy
Circulation vortex stuck to a wing
Conservation of Angular Momentum Angular momentum is constant for an object. (mass) x (angular velocity) x (radius)^2
Camber The shape of a wing. Crucial to determining lift
Scaling Determining how two variables relate to one another. For example, recognizing volume is approximately (length)^3
Center of Mass (CoM) A point which we can model as the center of the distribution of mass. As long as the CoM is above the BoS, the object/organism is statically stable
Base of Support (BoS) Area defined by supportive struts of object or organism. As long as the CoM is above the BoS, the object/organism is statically stable
Perturbation A force that threatens the stability of the object or organism at hand. For example, a gust of wind on a tree, or a person trying to tip a cow because, well, people do that sort of thing, apparently.
Upright animal Has low muscle and decreased static stability.
Turning The force required to turnaround a curve with a radius r.
Locomotion the ability to move from one place to another; movement
Mauthner Cell A pair of neurons that runs down each side of the body and are responsible for very fast escape reflexes.
Streamline Line of fluid where the local flow of velocity is tangent.
Resilience Elasticity of an object; the ability of an object to spring back into shape.
Plasticity The quality of being easily shaped.
Stiffness The quality of being strong.
Toughness The ability to withstand rough handling and adverse conditions.
Viscosity The state of being thick, sticky, and semifluid in consistency because of internal forces.
Viscous Forces The force between a body and a fluid that moves past it in a direction opposite of the flow of the fluid that passes the object.
Inertia The property of matter that keeps it at constant rest or uniform motion in a straight line unless acted upon by an outside force.
Inertial force The force that resists a change in the velocity of an object.
Motor Unit One motor neuron and all the fibers it innervates.
Muscle Spindle Sensory receptors in the muscle that senses the changes in muscle length.
upright animal low muscle force due to high EMA BUT decreased static stability
crouched animal high muscle force due to low EMA BUT increased static stability
Shear Modulus Shear Stress/Shear Strain
Strain Delta Length/Initial Length
Conservation of Mass a principle stating that mass cannot be created or destroyed.
Allometry study of the relationship of body size to shape, anatomy, physiology
Allometric growth The regular and systematic pattern of growth such that the mass or size of any organ or part of a body can be expressed in relation to the total mass or size of the entire organism
external pertubation can be external / internal - environment: obstacle, height, friction - external: carry offspring / prey - feeding - partintion autonomy
Hooke's Law force (F) needed to extend or compress a spring by some distance X is proportional to that distance.
primary forces of flight lift, weight, drag, thrust
adaptation of flight reduce mass, fuse bones, feathers, wings
evolution of flight birds, bats, insects, pterosaurs
stride stance + swing
Where is potential energy highest when walking Midstance
Where is kinetic energy lowest when walking Midstance
Van der waals attractive force (VP) weak attractive force. frictional force and contact electrification. has direction
Types of Attachments 1. Friction 2. Hooks 3. Locks and snaps 4. Clamps 5. Suction 6. Adhesive Secretions
oscillation repetitive movement, such as an up and down stroke while a fish is swimming
undulation wavelike motion such as stingrays
Types of vortices from a bird (VP) Bound vortex, tip vortex, and starting vortex
Forces resisted in adhesion Drag, Gravity
What is turbulent flow associated with? High drag
Breder 1926 defined mode of swimming based on genus name & patterns of motion
Thrust Force density x circulation of vortex x SA of circle
Systole (VP) contraction
Diastole (VP) relaxation
Lift is perpendicular to? Air flow
Drag is parallel to Fluid flow
High AR for fins minimual drag, good for long distance swimming. shape decreases viscous drag by low SA = efficent
Low AR for fins create drag, good for stop, turn, and burst of speed = inefficent. shape increases viscous drag by increasing SA
Wingbeat (VP) downstroke and upstroke(recovery phase)
Trade off a balance achieved between two desirable but incompatible features; a compromise
3 types of vortex on a wing 1. Tip vortex 2. Bound vortex 3. Starting vortex - vortex can't end in open space, must circle on self or to a solid structure
Rheotaxis (VP) fish turning to face an incoming current
Dorsal fins prevent Rolling
Dorsal fin an unpaired fin on the back of a fish
Why do birds fly in formation? the wings provide lift with the tip vortex and saves 20% energy for the neighboring birds from their tip vortex
Caudal fin Tail fin
Pectoral fin each of a pair of fins situated on either side just behind a fish's head, helping to control the direction of movement during locomotion
Which fins help prevent yawing All fins
Pectoral fins are used for Pitching
How do we visualize vortices Digital Particle Image Velocimetry
Flapping fins Up + down
Rowing fins Fins row back and forth, drag based thrust
How is lift created? The airfoil on the top has a longer path and has a higher velocity, so the pressure is lower. Below the airfoil has a lower velocity so the pressure is higher. Pressure goes from high to low so lift is created with a circulation that goes down to up.
Name an advantage Cling fish have over Geckos -Due to their soft rim they can attach to rough surfaces. Geckos rely on contact of hair so they require a smooth surface. dustin -the release of mucus allows Cling fish to attach to wet surfaces
What is the difference in a force versus times graph for running and walking? Running has a higher peak force and ends earlier while walking has a lower peak force. dustin -the area between the two graphs are the same.
As body size increases = GRF (increases/decreases)? increases dustin
Explain the trade off between high and low aspect ratio High would create minimal drag due to reduce in surface area -> long distance flying Low would create drag because of increase in surface are -> Manuevarability dustin
What is the drawbacks of C-start always accelerate in another direction dustin
Explain the trade off between EMA and stability High EMA = low muscle force and low static stability ->upright Low EMA = High muscle force and High static stability -> crouched dustin
External flexor moment r/R=G/Fm R is changing --> Fm will change to counteract it. dustin
Explain the wing loading trade off High wing loading -> small wings to fly dustin Low wing loading --> fly constantly and slowly
Whats the difference between C-start and s-start c-start is a unilateral muscle contraction while s-start contracts multiple parts of the body. dustin
Difference between BCF periodic and BCF transient BCF periodic is repeating and small acceleration BCF transitory is non repeating and high acceleration. dustin
what is the primary mechanism that allows geckos adhesion Van der Wals Interaction density of hair is 1 million/mm^2 dustin
Flow of energy in muscle tendon system for energy conservation. (Peter P.) Body => Tendon => Body
Flow of energy in muscle tendon system for power production. (Peter P.) Muscle => Tendon => Body
Flow of energy in muscle tendon system for energy absorption. (Peter P.) Body => Tendon => Muscle
Parallel muscle (Peter P.) Fibers or fascicles run the length of the muscle body.
Pinnate muscle (Peter P.) Fibers or fascicles are angled relative to the long axis of the muscle belly.
Irrotational vortex (Peter P.) One in which the different layers of fluid are rotating at different velocities.
Size principle of motor unit recruitment (Peter P.) As demand increases on the neuromuscular system, more motor units will be recruited. As the recruitment increases, additional (and larger) motor units will be added and force will rise exponentially.
Peak Power (Peter P.) 30% of Vmax
Positive Allometry (Peter P.) When something scales with size at a faster rate than is expected by isometry.
Muscle Fiber (Type 1) (Peter P.) Slow, oxidative. Allows you to perform slow behaviors that require endurance, but not a lot of force.
Muscle Fiber (Type 2A) (Peter P.) Fast, oxidative-glycolytic. Allows you to perform fast behaviors with some resistance to fatigue.
Muscle Fiber (Type 2B) (Peter P.) Fast, glycolytic. Allows you to perform fast behaviors that require a lot of force and quick response, due to its high innervation ratio.
Questions that can be answered using motion analysis. (Peter P.) 1. Descriptions of behavior. 2. How particular performance measures are achieved? 3. How do organisms respond to different treatments?
First class lever (Peter P.) Fulcrum placed between the effort and load.
Second class lever (Peter P.) Load in-between the effort and the fulcrum.
Third class lever (Peter P.) Effort between the load and the fulcrum.
What are the two ends of the continuum for modes of swimming? Undulation to Oscillation
Webb 1984 Proposed BCF periodic, BCF transient, MPF, and Ocassional modes of swimming.
What does stride length x stride frequency =? speed
How does CSA scale to Mass? CSA = Mass^(2/3)
What is the major antagonistic force in aquatic locomotion? Drag
What are the 3 factors involved in contractile force of muscles? size of MU, # of MU involved, thicknes off muscle cells.
What does "all-or-nothing" refer to when discussing Motor Units? All fibers innervated by the neuron of the motor unit will all contract when an action potential and will not contract when an action potential is not fired.
What is motor unit recruitment? process of increasing and conferring activation of motor units to produce more force.
Blood Velocity Flow/CSA of blood vessels
What happens to a vortex when its radius increases? velocity decreases
What is the midpoint during a walk the highest point reached
what is the midpoint during a run the lowest point reached
What is stride length? Distance
What kind of ______ joint moment must have occured for an extensor muscle moment to balance it? flexor
What kind of ______ muscle moment must have occured for an extensor joint moment to balance it? flexor
Steps of Feeding (VP) 1.) locate prey and move to prey. 2.) Capture/subdue prey. 3.) process/ingest prey
Sensory systems (VP) Vision, smell, sound, mechanical, temperature
Performance (VP) Ability to perform ecologically relevant task
Jaw Protrusion (VP) Move flow closer to prey
Hyoid depression and cranial elevation (VP) Expands mouth cavity
Diversity of feeding (VP) Prey type and medium of the habitat
Epaxial muscle (VP) Cranial elevation
Sternohyoid (VP) Hyoid retraction
Hypaxial muscle (VP) Cleithrum retraction
Ways animal feed filter feeding, suction feeding dustin
suction feeding mode H2O to entrain the pray small mouth rapid prey velocity small non evasive prey dustin
Ram feeding mode predatro over take the prey large mouth rapid predator velocity pursue evasive prey.
Explain mechanism for tongue projection tongue is attached to front of the mouth. muscle contracts -> pulls base of the tongue down inertia extends soft mass of tongue when tongue flips out of mouth. dustin
Hysterisis percent energy lost, can be found by calculating the area between the curves
Resilin facilitates flexibility in wings, 50% water, 90% efficiency
Resilience Modulus
J-shaped curve compliant to a point then just stiff, examples include arteries of human circulatory system and neck muscle of deer
keratin beta-keratin stronger than alpha-keratin, structural protein found in integument of vertebrates
fascicles bundle of muscle fibers
sacromere made up of thick myosin filament and thin actin filament
myosin thick filament, motor protien, structure: head=ATPase, tail=binding, neck=regulates ATPase
actin thin filament
why is ATP important in muscle contraction? required for detachment of myosin from actin
why is Calcium important in muscle contraction? required for attachment of myosin to actin
Sliding Filament Model (SFM) similar to pulling a rope, alternating cycle of grasping and releasing the rope with actin=rope and myosin=hand
what is the trade-off for super fat muscle? low force and high velocity
What are some differences between suction and ram fish? Suction fish-small mouth, rapid prey velocity, small and non-evasive prey Ram fish-large mouth, rapid predator velocity, evasive prey
Which muscles are used for jaw profusion in fish? epaxial muscle, sternohyoid, and hypaxial muscle
Equation used for mammalian chewing out moment (FoLo) = muscle moment (LiFi)
Fatigue 1. Everyone experiences fatigue 2. Fatigue ability increases with age 3. Critical for survival 4. Important for many clinical conditions.
Muscle Fatigue a reduction in maximum muscle force due to exercise
Two factors in fatigue central and peripheral
Factors in central fatigue adenosine, cognitive aspect, mental tiredness, inhibition of motoneurons due to muscle input, discharge frequency of spinal motor neurons
Factors in peripheral fatigue lactic acid, glycogen depletion, sarcomere damage, acetylcholine depletion, increase extracellular K+, increase inorganic phosphate from breakdown of creatine phosphate
adenosine reduces arousal and inhibits excitatory neurotransmitters in brain
lactic acid performance enhancer that increases force
Late 1800s study in relation to exercise In a matter of 2 weeks 1. strength training in one arm --> trained arm 70% increased force, arm not trained 40% increase force 2. control --> no change in strength
1992 study in relation to exercise Showed how important CNS is 1. control --> no change in strength 2. subjects exercised --> 30% increased force 3. subjects imagined they exercised --> 22% increased force
Human Training individuals respond differently, could be related to ACE gene
Mosso's Findings (1891) first to state that individuals vary with fatigue, even though test subjects all did same task and age still different results
4 Basic Aerodynamic Forces Thrust, Lift, Drag, Weight
External joint moments on graph Moment (N*m) on y-axis Time (s) on x-axis + <180 = flexor joint moment, extensor muscle moment - > 180 = extensor joint moment, flexor muscle
Fatigue ability defined as time it takes for muscle to fatigue
for walking when is PE highest? midstance
what blocks adenosine receptors? caffeine
dorsal back
ventral stomach side
anterior towards head
posterior/caudal towards bottom
proximal near center
lateral towards side
what makes a good morphological description? you can draw a basic map of the features based on the description
homology shared characteristics due to a common ancestor
morphospace graph describing morphologies where each axis represents a character or even a combination of characters
disparity measure of how variable a group is
medial midline
distal far from center
constraints restriction, limitation or bias in the course of evolution 3 major types: phylogenetic, developmental, functional
Morphology The study and description of form
What features make up a good morphological description? -anatomical terms of location -features that are close to the point of interest -points of reference to describe a feature -concise and consistent
Theoretical morphology Defining what are the possible forms by using mathematical and geometric rules
In morphospace what do the points closer in space represent? Represents forms that look very similar to each other
In morphospace, what do the points farther in space represent? Represents forms that look very different from each other
Phylogenetic constraint constraint based on the trajectory the group has historically taken
Developmental Constraint The developmental pathway is constrained in a particular way
Functional Constraint The form may not be physically possible or not suited to an animal’s needs
What are the types of relationships that morphology can have with performance? one to one mapping one to many mapping many to one mapping many to many mapping
One to one mapping one morphological trait can be related to one functional trait
One to many mapping One morphological trait is related to many functional traits
Many to one mapping Many forms can perform the same function (when one function is made up of 3 or more parts)
Many to many mapping Multiple forms affect multiple functions
Redundancy the more parts, the more potential there is for this relationship
What is MicroCT and list 3 different modeling techniques MicroCT helps with capturing 3D complex shapes Techniques: computational fluid dynamics X-Romm and animation Finite Element Analysis
Duty factor - walking Each leg contacts the ground for more than half the total stride time - duty factor > 50%
Adjust speed in gaits By changing stride length but not usually stride frequency.
Power related to two gaits Going slower, walking is cheaper; going faster, running is cheaper.
Compressive stress rule All animals hit about the same peak compressive stress in their leg bones.
weakening of coral reefs increased wave forces and lowering of pH
components of reproductive isolation Hybrid inviability and Migrant inferiority, both informing Biomechanics
phenotypic plasticity non-genetic differences in phenotypes
Bone compressive strength about 200 megapascals
Load carrying - humans that the cost of carrying a load by a human male differs in no significant way from the cost of self-transport.
GT speed speed at which fish go from pectoral to caudal fins
Lauder paper purpose How to measure thrust in fluid
linking biomechanics and speciation stablishing the genetic basis of biomechanical traits, testing whether similar and divergent selection lead to biomechanical divergence, testing whether/howbiomechanical traits affect RI
Muscle CSA scale body mass overall muscle cross section will scale with body mass to the power 0.67—indistinguishable from 0.68.
Transport cost scale body mass the minimum metabolic cost of transport scales with body mass to the power –0.32
Galloping An asymmetrical gait - the paired legs - the two front legs operate almost simultaneously, as do the two hind legs - don’t synchronize exactly, with one always striking just before the other.
Prey Type (Hoon) Evasive vs sessile Hard vs soft Large vs small
Sensory Sytems (Hoon) Characteristics to locate prey and move to it Vision, Smell, Sound, Mechanical, Temperature
Frog Tongue Projection (Hoon) Tongue is attached to front of mouth. Muscle contracts and pull bottom of the tongue down which causes tip of tongue to flip out of mouth
Walking Stride (Hoon) KE and PE energy exchanged during locomotion (Out of phase)
Running Stride (Hoon) KE and PE not equally exchanged. Delta U = Delta KE + Delta PE
Isometric muscle contraction (Hoon) Same length during a contraction Ex. Holding a book
Concentric muscle contraction (Hoon) Muscle shortening when generating force Ex. Lifting an object
Eccentric muscle contraction (Hoon) Muscle lengthening when generating force Ex. Slowly lowering an object
Jumping bush babies movement (Hoon) Fast motor units recruited without slow muscles
Fish escape response (Hoon) Fish can recruit white muscles only to maximize short term escape speed
Muscle Spindles (Hoon) Sensory receptors within muscle to detect changes in length. Prevent overstretch
Golgi Tendon Organ (Hoon) Senses changes in muscle force to prevent muscle damag
Positive work loop (Hoon) Shortening of muscle on a Force x Length Curve (Concentric contraction)
Negative Work loop (Hoon) Lengthening of muscle on a Force x Length Curve (Eccentric Contraction)
Pennation Angle (Hoon) A pennate or pinnate muscle (also called a penniform muscle) is a muscle with fascicles that attach obliquely (in a slanting position) to its tendon. These types of muscles generally allow higher force production but smaller range of motion When a muscle
Anteromedial (Julia) anterior + medial
Theoretical morphology (Julia) What things could look like in comparison to what things actually look like
Theoretical morphospace (Julia) Not constructed by measuring already existing forms; Uses simulation and therefore creates a map of all existing forms adhering to designated rules.
3 Major Types of Constraints (Julia) 1. Phylogenetic Constraint 2. Development Constraint 3. Functional Constraint
One to One Mapping (Julia) Assumes one morphological trait related to one function; measure what is thought to be a biomechanically relevant trait; often use these results to predict of a untested animal
One to Many Mapping: Facilitation (Julia) Tells us that the demands of related different functions may be similar in some way; e.g. Leg length, jump height, & sprint speed
One to Many Mapping: Trade-Off (Julia) May tell us that relating functions are competing in some way; e.g. pennation angle, contraction force, and contraction speed
Many to One Mapping (Julia) a potential mechanism of weakening trade-offs; i.e. If one part of the function fails, other parts can make up for it
Four bar linkages in fish (Julia) Depending on the shape of the four bar linkage, opening the jaw will cause the upper jaw to rotate to different degrees
Geometric morphometrics (Julia) Method of quantifying shape by placing landmarks on homologous structures across many specimens; Gives us methods for better information than linear measurements; Creates morphospaces where the axes are combinations of variables
X-Romm (Julia) X-ray video taken through time and can be either 2D or 3D; fluorescent markers are used to track points in the skeleton to see how specifically the bones move; the video can be enhanced by designating the same points to a microCT model to align the bones
Finite element analysis (Julia) method for prediction how model reacts to real world forces: break down 3D models into manageable "bricks" - tiny parts; apply physics equations based on their material properties that are told to the computer
Turbulence (Julia) the random motion of fluid in space and time
Gliding (Julia) always descending, losing air speed
Wing beat in flapping flight (true flight) (Julia) down stroke (flapping down) = high force, up stroke (recovery) = low force; the forward component of the two actions creates thrust
Created by: mvzhuang