Musculoskeletal Forces

Question 1

what are external forces?

Answer 1

forces acting outside the body

Question 2

what are internal forces?

Answer 2

forces derived from inside the body

Question 3

What are the type of Internal forces?

Answer 3

Active forces
Passive forces

Question 4

what are active forces?

Answer 4

forces produce by activated muscles

Question 5

what are passive forces?

Answer 5

generated by passive tension in deformed tissue

Question 6

Why do we produce internal forces?

Answer 6

predominantly via muscle contraction in order to control external movement tasks

Question 7

What is the result of internal and external forces?

Answer 7

loading of body tissue

Question 8

What are the external forces that act on the musculoskeletal system?

Answer 8

Gravity
Wind
Friction

Question 9

What are examples of internal forces?

Answer 9

muscle
ligament
tendon
cartilage

Question 10

what are examples of external forces?

Answer 10

gravitational forces
ground reaction forces

Question 11

What is point of force application?

Answer 11

where the forces are applied

Question 12

What is angle of force application?

Answer 12

the direction in which the force is applied

Question 13

What is angle of muscle insertion?

Answer 13

The orientation of the muscle insertion relative to the long axis of the bone

Question 14

What does the angle of muscle insertion dictate?

Answer 14

Dictates the angle at which the muscle applies force to move the segment

Question 15

What is the moment or lever arm?

Answer 15

The perpendicular distance between the axis of rotation and the application of force

Question 16

What does D and D1 represent?

Answer 16

D: internal muscle force moment arm
D1: external force moment arm

Question 17

What are internal joint moments?

Answer 17

the product of the internal force and moment arm
ex: bicep produces flexion moment in elbow

Question 18

what are external joint moments?

Answer 18

the product of the external forces and the external moment arm
ex: rotating elbow clockwise to extend elbow

Question 19

What causes force production?

Answer 19

Activation of muscles by the nervous system

Question 20

What are the types of muscle activation?

Answer 20

Isometric
concentric
eccentric

Question 21

What is an isometric activation?

Answer 21

no movement of segment arm is in balance

Question 22

What is an concentric activation?

Answer 22

force of muscle is able to exceed the external force on the arm

Question 23

what is an eccentric activation?

Answer 23

external force overpowers the internal force; resists being pulled apart

Question 24

What is the muscle actions at a joint?

Answer 24

The potential for the muscle to cause a moment in a particular rotation direction and plane

Question 25

What are the planes of movement?

Answer 25

Frontal Horizontal Sagittal

Question 26

What movements happen in frontal plane?

Answer 26

abduction adduction

Question 27

What movements happen in horizontal plane?

Answer 27

external rotation internal rotation

Question 28

What movements happen in the sagittal plane?

Answer 28

flexion extension

Question 29

What is an agonist muscle?

Answer 29

muscles most directed related to the initiation and execution of a movement

Question 30

What is an antagonist muscle?

Answer 30

muscles hat have the opposite action as the agonist

Question 31

During Knee flexion which muscle is the agonist?

Answer 31

Hamstrings

Question 32

During knee flexion, which muscle is the antagonist?

Answer 32

Quadriceps

Question 33

what is muscle synergy?

Answer 33

muscle groups that work together to execute a moment in a smooth and coordinated manner ex: sit to stand uses extensor muscle group synergy

Question 34

What is muscle force couples?

Answer 34

two muscles producing force in opposite directions resulting in a moment in the same direction ex: the pelvis tilting

Question 35

What are the types of lever systems?

Answer 35

1st class 2nd class 3rd class

Question 36

Lever systems should be _____

Answer 36

Static Rotary Equilibrium (in balance)

Question 37

What is the first class lever system?

Answer 37

External Force and Internal force are on opposite sides, have same magnitudes and same external and internal moment arms are the same distance

Question 38

What is the 2nd class lever system?

Answer 38

Internal force has higher moment arm than external moment arm; external force is closer to axis of rotation and has less mechanical advantage; force needs to be higher to keep system in balance

Question 39

What is the 3rd class lever system?

Answer 39

Internal force is closer to axis of rotation than the external force; internal force has to be doubled of external force; external forcer has larger moment arm; force need to be doubled the size of external force to keep system in balance

Question 40

What is Statics?

Answer 40

Study of forces actin on a body at rest or moving with a constant velocity

Question 41

What does static analysis provide?

Answer 41

A simple method for analyzing musculoskeletal problems and used to inform clinical physical therapy decision-making

Question 42

What are the three laws on Newton?

Answer 42

Law of inertia Law of acceleration Law of reaction

Question 43

What is the law of inertia?

Answer 43

an object at rest or traveling at a constant velocity remains at rest (or at constant velocity) unless acted upon by an external force

Question 44

What is mass?

Answer 44

quantity of matter in an object

Question 45

What is mass moment of inertia?

Answer 45

the amount and how mass is distributed in an object

Question 46

what can inertia be thought of?

Answer 46

An object's stubbornness to move

Question 47

What is inertia proportional to?

Answer 47

an object's mass

Question 48

what is the law of acceleration?

Answer 48

If unbalance forces are acting on an object, a proportional acceleration in the direction of the greatest force is produced

Question 49

What is law of reaction?

Answer 49

for every acton (force), there ia a reaction (opposing force) of equal magnitude but in the opposite direction; ground reaction forces

Question 50

what is static equilibrium?

Answer 50

the sum of the internal and external forces and moments acting on the body are equal to 0

Question 51

What is static Rotary Equilibrium?

Answer 51

the internal and external moments are equal and opposite