lecture 4: biomechaics Flashcards

1
Q

what are the passive strtuctures of th musculoskeltal system

A

bones
carinlage
joiints
ligaments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are the active elements of the musuloskeltal sysmte

A

muscles/tendons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is the MSK system

A

systems capable of resisiting or generation motion at joints

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is biomechanism

A

the strudy of the structure and functon of living systems through principles of mechanics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is biomechannics in terms of the MSk

A

largerely the study of movement (locomotion)
=forces (kinetics)
movement (kinematics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

whats the name for forces

A

kiinetics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

whats the name for movment

A

kinematics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is tthe function of knowing biomechanism

A

treating muscles bones, joints as lever systems helps to understand their function, if if you cant remember it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

why use biomechanisms for dysfunction

A

many patietnes will have symptoms that reflect inablity and/or weakness in performing certain movements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is the definition of a lever

A

a simple machine consisting of a rigid body that can rotate at a fixed point (fulcrum) in response to forces applied somewhere along its length

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is torque

A

the tendency of a force to cause an object to rotate around a certain points

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is the formula for torque

A

torque= force x perpendicualr distance to the fulcrum (lever)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Ffor the same force, would a half lever length or full lever length generate most torque

A

full levre length

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what happens is the force and lever are parralel

A

no torqur created

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

in the MSK, what is considered the lever

A

the bones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

in the MSK, what is considered the fulcrums

A

joints

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

in the MSK, what is considered the forces applied

A

external (gravity) or muscular
=creates torques at the joints

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

true or false: muscles can produce force by pushing

A

false, muscles can only pull (ie: muscles work thru tension)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

true or false and why: MSK lever systems are composite

A

true because there are greater than 2 muscles that generate torques on opposite sides of the joint (ie: triceps vs biceps brachii)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

whta is the agonist and give ane xample

A

perform the action (ex: bicep flexion of elbow)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is an antagonist and give example

A

performs opposite action of agonist
(ex: tricps extends the elbow)

22
Q

what is the synergiest and give example

A

assists the agonists (brachialiss assists in. biceps in elbow. flexion)

23
Q

what are. stabilizers and give. examples

A

stabilize the joints, fine tunes the movements
(ex: anconeus stabilizes elbow jointns in extension)

24
Q

what are the muscle common external forces

A

gravoty
ground raection forces

friction

25
Q

what are ground reactiton fcores

A

for every force there is an equal and opposite force (ex: gravity vs the ground pushing back p)

26
Q

what is the difference between load arm and lever arm

A

load arm is the distance between the joints to the load
and the lever arm is the distance btween the joints (fulcrum) to the muscles line of action

27
Q

external force is AKA

A

load

28
Q

distance to. load is AKA

A

load arm

29
Q

internal muscle force is AKA

A

effort

30
Q

distance to effort is AKA

A

lever arm

31
Q

when is equilibrium reached

A

torques are equal and cancel out (effort=load)

32
Q

how do we get from torque to actual angular motion

A

torques are not equal
angular motion (rotation) direciton and speed depends on which torque is greatest

33
Q

what is angular motion

A

force that generations rotational force

34
Q

what does angular motion’s speed and direction depend on

A

which troque is greatest

35
Q

Picture a man holding the points stead (equilibirum), explain the muscle involvement and the torques

A

isometric contraction of the biceps (effort) that generates equal and opposite torque to resist the torquecreated by weight of the pint

36
Q

picture a man taking a sip of his beer and explain the muscles and torqur involved

A

biceps torque is greater tthan the pint torque
=causes elbow flexion through concentric cocntraction of the biceps (fibers shortneing)

37
Q

picture a man putting his beer down after drinking and explain the muscles and torqur involved

A

pint torque is greather than biceps torque which causes elbow extension but controlled through the eccentric conraction of the biceps

38
Q

how can you get more torque

A

increase the force (ie: larger muscle)
longer lever arm
increase D (upside down T)

39
Q

how can some mnuscle lever systems be boostted

A

by bony protructions that length the lever arm (exL processes, tubercles
=improves muscle ability to generate torque)

40
Q

when you squat, what external force is applied to the femur and what torque is produced at the knee

A

trunk weight

41
Q

what kind of angular motion would squatting created

A

flexion of the knee

42
Q

what would resistt the trunk weight

A

extensors of the knee (quads)

43
Q

how does quadricep effort chagne with increases knee flexion

A

incrase flexion=increase effort (more gravity load arm increases)

44
Q

how does muscle contrtaction change with increasing/decreasing flexion

A

static=iso
down squation-eccenttric
up squat= concentric

45
Q

angular motion AKA

A

rotation

46
Q

fulcrum defintion

A

center of rotation= axis

47
Q

external force aka

A

load
out-force
resistnace

48
Q

internal force AKA

A

muscle force
effort

49
Q

load arm is condiered what lever

A

out lever

50
Q

lever arm is consideered what lever

A

in. lever

51
Q

what is the def of torque

A

moment of force