Midterm 2

Question 1

Bone Functions

Answer 1

PAAP
Provide mechanical support
Acts as a lever
Attachment sites
Protection, storage RBC formation

Question 2

Epiphyseal Plate

Answer 2

Growth plate; when damaged can stop growth

Question 3

Stress

Answer 3

a load applied per cross-sectional area
-how big

Question 4

strain

Answer 4

deformation, a change from the initial length
-how long

Question 5

What can affect a stress-strain relationship?

Answer 5

Loading, Tissue and Direction of Loading

Question 6

Types of Loading

Answer 6

Tension, Compression, Bending, Shear, Torsion, Combined loading.

Question 7

Newtons Laws of motion
LAW 1

Answer 7

Law I – The Law of Inertia
Every body continues in its state of rest, or of
uniform motion in a straight line, unless it is compelled to change that state by force s impressed on it.

Question 8

Newtons Laws of motion
LAW 2

Answer 8

Law II – The Law of Acceleration
The change of motion is proportional to the force impressed and is made in the direction of the straight line in which that force is impressed.

Question 9

Newtons Laws of motion
LAW 3

Answer 9

Law III – The Law of Action-Reaction
To every action there is always an opposite and equal reaction; or, the mutual action of two bodies upon
each other are always equal and directed in opposite directions.

Question 10

Why is Bone Important?

Answer 10

Bone is a living Tissue
-provide a strong framework to support and protect the soft organs (such as the brain, heart, and lungs) from injury. Bone works with muscle to hold up the body when we stand and to move the body when we walk or run. Bone houses the bone marrow, which makes blood cells.

Question 11

WOLFF’S LAW

Answer 11

our bones become thicker and stronger over time to resist forces placed upon them and thinner and weaker if there are no forces to act against.
-bone is laid down at sites where needed and reabsorbed from sites where not needed
-USE IT OR LOOSE IT

Question 12

osteoclasts

Answer 12

-reabsorb or take up bone

Question 13

osteoblasts

Answer 13

-lay down new bone

Question 14

Osteoporosis

Answer 14

severe bone loss resulting in gaps in the structure

Question 15

Transverse Fracture

Answer 15

-occurs at 90 deg angle
-caused by bending force, snaps

Question 16

Oblique Fracture

Answer 16

-occurs sloped down/up at an angle or curve
-caused by tracing one bone while the other twists over it.

Question 17

Spiral Fracture

Answer 17

-fracture spirals around the bone
-caused by twisting force

Question 18

Comminuted Fracture

Answer 18

-fracture breaks into multiple pieces
-caused through crushing force

Question 19

Avulsion Fracture

Answer 19

-ligament or tendon pulls away from its attachment on the bone and a fragment of bone breaks off with it.
-a muscle contraction or stretch that is stronger than the force that holds the tendon/ligament together.

Question 20

Impacted Fracture

Answer 20

-occurs in the middle of the bone, driven into its self then buckles.
-caused by compression of the bone from end to end

Question 21

Fissure or Hairline Fracture

Answer 21

-an incomplete fracture; multiple small lines are often visible, but don’t pass through the entire bone.
-caused by any force that could cause any other type of fracture, but is not great enough to completely break the bone.

Question 22

Greenstick Fracture

Answer 22

-bone bends rather than breaks
-occurs most often in children in bones that have not completely ossified and still contain cartilage

Question 23

Force

Answer 23

Vector quantity, mechanical interaction between an object and its surrounding. measured in newtons

Question 24

Force Platform

Answer 24

instrument used to measure the reaction forces in 3 divisions (X,Y,Z). and moments about those 3 axis.
-limitations: mounting, altered walking patterns, conscious walking

Question 25

Moment of Force

Answer 25

-the rotary effect of a force; also called torque. measured in newton metres nm
-clockwise rotation: negative moment
-counterclockwise rotation: positive moment

Question 26

Mass

Answer 26

the amount of matter kg

Question 27

Weight

Answer 27

the amount of gravitational attraction between an object and the earth
-9.81m/s2

Question 28

Ground Reaction Force

Answer 28

the reaction force provided by the horizontal support surface.

Question 29

Centre of Pressure

Answer 29

the point on a plane surface at which the resultant pressure on the surface may be taken to act.

Question 30

isokinetic contraction

Answer 30

A movement in which the angular velocity of the displaced body segment is constant.
Ex- breaststroke when swimming, where the water provides a constant, even resistance to the movement of adduction.

Question 31

isotonic contraction

Answer 31

A muscle contraction in which a muscle contracts and does work against a constant load.
EX-Isotonic exercises are any where the length of a muscle changes. Examples include bicep burls, push-ups, pull-ups, and contractions occurring in the legs while running.

Question 32

Draw Force Length Graph

Answer 32

Draw

Question 33

Draw Force Velocity Graph

Answer 33

Draw

Question 34

Equation to find force/ weight

Answer 34

F = ma

Question 35

Calculating moments

Answer 35

Find direction of force, a should be perpendicular to force, counterclockwise is positive,unit of measurement is nm Newton metres
M=Fd

Question 36

Describe and explain force-length relationship

Answer 36

Look to notes

Question 37

Describe and explain force-velocity relationship

Answer 37

Look to notes