Biomechanics

Question 1

Biomechanics

Answer 1

Principles of forces and motion as applied to the structure and funciton of the human body

Question 2

Static

Answer 2

Factors associated with non moving systems

Question 3

Dynamics

Answer 3

Factors associated with moving systems

Question 4

Law of inertia

Answer 4

An object at rest tends to stay at rest, and an object in motion tends to stay in motion
- force is needed to move, stop, or change the direction of an object

Question 5

Law of acceleration

Answer 5

Amount of acceleration depends on the strength of the force applied to an object

• the change in an object’s direction depends on the force applied
• acceleration is inversely proportional to the mass of the object

Question 6

Law of motion

Answer 6

For every action, there is an equal and opposite reaction

Question 7

Force

Answer 7

Any influence that results in the movement of an object

• point of application
• vector

Question 8

Vector

Answer 8

A quantity that describes magnitude and direction

Question 9

Internal force

Answer 9

Muscle, ligamentos restraint, bony support

Question 10

External force

Answer 10

Gravity, weight, friction

Question 11

Linear force

Answer 11

Two or more forces activing along the same line

Question 12

Parallel forces

Answer 12

Occur in the same plane and in the same or opposite direction

Question 13

Concurrent forces

Answer 13

Two or more forces applied to the same point but pulling in different directions
- resultnat force is dependent on angles of pull and magnitude

Question 14

Force couple

Answer 14

Two or more forces acting in equal but opposite directions to facilitate a rotation

Question 15

Torque

Answer 15

A force that causes a rotation about an axis
- increases as the force applied increases or the distance from the axis increases

Torque = force x distance

Question 16

Moment arm

Answer 16

The perpendicular distance between the force’s line of pull to the axis of rotation

Question 17

Stabilizing force

Answer 17

Torque that results in compression of joint

- occurs at angles <90

Question 18

Angular force

Answer 18

As stabilization or dislocation force

- greatest at 90

Question 19

Dislocating force

Answer 19

Torque that tends to pull a joint apart or destabilizes it

- occurs with angles >90

Question 20

Pic

Answer 20

Pic

Question 21

Stability

Answer 21

A state of equilibrium defined by the orientation of the COG relative to the BOS

Question 22

Stable equilibrium

Answer 22

Can be disturbed or upset only if the COG is elevated

- normal cone

Question 23

Unstable equilibrium

Answer 23

Minimal force required to disturb or upset

- cone on tip

Question 24

Neutral equilibrium

Answer 24

COG unchanged when disturbed

- cone on side

Question 25

Improve stability

Answer 25

- lower COG - increase BOS - increase mass - increase friction - focus on stationary object

Question 26

Lever system

Answer 26

Simple mechanical device that makes the work of moving a weight or other load easier

Question 27

Levers

Answer 27

Provide mechanical advantage either in power or distance (ROM) - rigid bar (bone) - fulcrum or axis - load or resistance - force (muscle contraction)

Question 28

First class levers

Answer 28

F - A - R Favors balance

Question 29

Second class levers

Answer 29

A - R - F Favors force and power

Question 30

Third class levers

Answer 30

A - F - R Favors ROM