Biomechanics Pt. 2 (9/3c)

Question 1

Proximal on Distal / Distal on Proximal

Answer 1

Different ways of moving, but provides same essential movement

If a Pt is struggling with a motion (EX: prox on dist), you could consider the complimentary motion (EX: dist on prox)

Question 2

Kinetics

Answer 2

describes the effect of forces on the body

Question 3

Force

Answer 3

a push or pull that can produce, arrest, or modify movement

Force = mass*acceleration

Question 4

When acceleration is zero, force equals ___

Answer 4

zero

Question 5

Standard International Unit for Force

Answer 5

Newtons (N) = 1 kg x 1 m·s2

Question 6

Force is mathematically displayed/defined as a ___

Answer 6

vector

Question 7

Vector

Answer 7

has magnitude AND direction, often represented by arrows

Magnitude = length

Direction = indicated by arrow head

Question 8

Internal forces (IF)

Answer 8

forces derived from inside the body

Question 9

External forces (EF)

Answer 9

produced by forces acting outside the body

Question 10

Humans produce IFs mostly via ___ ___ to control EFs during movements

Answer 10

muscle activation

Question 11

Interaction between IFs and EFs result in

Answer 11

Loading of body tissues

Question 12

Active forces (IF)

Answer 12

forces produced by activated muscles

Question 13

Passive forces (IF)

Answer 13

forces generated by passive tension in stretched tissues

Question 14

Examples of external forces

Answer 14

Gravity, wind, friction

Question 15

Point of application

Answer 15

where forces are being applied

Especially in relation to joint’s axis of rotation

Question 16

Angle of insertion

Answer 16

orientation of the muscles insertion relative to the long axis of the bone

Dictates the direction of application of force to the bone

Question 17

Moment arm/Mechanical advantage

Answer 17

distance between the force acting on the body and its axis of rotation

Muscle force is applied to the bone segment at a distance (D) from the axis of rotation of the joint

D1 moment arm > D moment arm

Question 18

D1 moment arm is (less than/equal to/greater than) D moment arm?

Answer 18

Greater than >

Question 19

Joint moment

Answer 19

muscle force x moment arm

D= muscle force moment arm

D1= external force of gravity acting on forearms center of mass

Question 20

Moment

Answer 20

torque

Question 21

Linear kinematic measures

Answer 21

Force

Newtons (N) OR Pounds (lbs)

Question 22

Angular kinematic measures

Answer 22

Moment/torque

Newtons x meters (Nm) OR Foot pounds (ft-lbs)

Question 23

Static Linear Equilibrium

Answer 23

internal force = external force

EX: Internal force= biceps muscle force
External force= weight of forearm
Joint reaction force= reaction force of humerus pushing down

Question 24

Static Rotary Equilibrium

Answer 24

internal moment = external moment

no rotation occurs around the joint

Question 25

Internal moment (IM)

Answer 25

muscle force x internal moment arm

Question 26

External moment (EM)

Answer 26

external force x external moment arm

Question 27

Muscle action

Answer 27

potential for a muscle to produce osteokinematic rotation around an axis of rotation in a plane of motion

based on anatomical positions and there can be multiple movements based on orientation

Question 28

When a muscle contracts, the ___ segment moves

Answer 28

Freest

Question 29

3 Types of Muscle Activation

Answer 29

Isometric
Concentric
Eccentric

Question 30

Isometric muscle activation

Answer 30

muscle produces force while maintaining constant length

Internal moment = external moment

Question 31

Concentric muscle activation

Answer 31

muscle produces force while shortening

Internal moment > external moment

Question 32

Eccentric muscle activation

Answer 32

muscle produces force while lengthening

Internal moment < external moment

Muscles do not actively lengthen

Question 33

Agonist muscle

Answer 33

muscle or muscle group most directly related to initiation or execution of a movement

EX: biceps = agonist for elbow flexion

Question 34

Antagonist muscle

Answer 34

muscle or muscle group that has an opposite action of the agonist muscle or group

EX: triceps = antagonist for elbow flexion

Question 35

Muscle synergy

Answer 35

muscles often work together to produce a particular movement/task

Question 36

Force couples

Answer 36

forces in opposite directions working together to produce a movement in one, same direction

EX: turning a steering wheel