Lecture 1

Question 1

Importance of Biomechanics

Answer 1

• helps identify when spine is moving abnormally by knowing how it works normally
• identifying the force/loads spine has been exposed to through patients

Question 2

Spinal Motion Segments
Typical Spinal Functional Unit

Answer 2

• C2/C3 to L4/L5

Question 3

Spinal Motion Segments
Atypicial Spinal joints

Answer 3

• C0/C1
  -C1/C2
  -L5/S1
  -Sacroiliac joint
  -Sacrococygeal joint ( considered apart of the spine.)

Question 4

What does each spinal motion segemet have

Answer 4

Each has a unique
-Appearance
-Facet orientation
-Pattern of motion
-Instantaneous Axis of Rotation (IAR)

Question 5

How do you describe the movement/postion of a mtoion segement by convention?

Answer 5

ALWAYS with respect to the vertebra below. (posterior)

Question 6

IAR

Answer 6

Instantaneous Axes of Rotation

Question 7

What does IAR mean?

Answer 7

When an object moves, the axis around which the movement occurs can change in placement from one instant to another. The IAR is used to denote this point.

So with each movement of flexion, neutral and extension movement the IAR is moving of the head

Question 8

Describe movement

Answer 8

right-handed orthogonal coordinate system - a way to describe movement of the spine

• human body is 3D function therefore 3 axis in right angled. +x +y & +z

Question 9

y axis poles

Answer 9

superior +
inferior -

Question 10

x axis

Answer 10

left +
right -

Question 11

z axis

Answer 11

anterior +
posterior -

Question 12

saggital plane

Answer 12

Left and right

Question 13

coronoal

Answer 13

anterior
posterior

Question 14

transverse

Answer 14

superior
inferior
medially

Question 15

Whar forms the y-axis?

Answer 15

intersection of sagittal and coronal (frontal) planes

Question 16

What forms the x- axis

Answer 16

Formed by intersection of frontal and transverse planes

Question 17

What forms the z- axis

Answer 17

formed by intersection of sagittal and transverse

Question 18

Describe Degrees of Freedom

Answer 18

The number of coordinates needed to fully describe the motion of an object

• motion of rigid body in space = 6 degrees of freedom
  characterised by tranlation along, rotation about and each of the 3 axes - x. y, z

Question 19

Translation

Answer 19

movement along an axis
3 degrees of Freedom along an axis
+ and - pole on a particular translation movement

Question 20

Rotation

Answer 20

movement around an axis
3 degrees of freedom around an axis
+ and - rotation about an axis that corresponds to a particular rotational movement

Question 21

θ

Answer 21

rotation

Question 22

Cervical Curve

Answer 22

Anterior convex curve (lordosis) develops in infancy – Infant begins to lift head

Question 23

Thoracic Curve

Answer 23

• Posterior convex curve (kyphosis) present at birth

Question 24

Lumbar Curve

Answer 24

Anterior convex curve (lordosis) develops in response to weight bearing –
Influenced by pelvis and lower extremity positioning

Question 25

Sacrococcygeal Curve

Answer 25

Posterior convex curve formed from the fused sacral and coccygeal segments

Question 26

Postural Analysis

Answer 26

evalutae structure & fuction doctor from behind (P-A) and laterally

Question 27

Describe Plumb line

Answer 27

is typically a straight, vertical line that is aligned with the force of gravity

Question 28

Describe lateral view - postural anaylsis

Answer 28

The plumb line should pass through specific landmarks such as the external auditory meatus (ear canal), shoulder joint, hip joint, knee joint, and ankle joint

Question 29

Deviations lateral view - postural anaylsis

Answer 29

may indicate postural imbalances or abnormalities

Question 30

Describe the Postural Analysis- Frontal view

Answer 30

The plumb line can be used to assess any lateral deviations or tilts - Feet are equidistant from the plumb line - Feet are parallel - Through the midline of the body

Question 31

Importance of assessing Postural Analysis- Frontal view

Answer 31

This is important for identifying asymmetries or uneven weight distribution

Question 32

Pronation

Answer 32

leaning inward - ankles

Question 33

Supination

Answer 33

leaning outward

Question 34

Centre of gravity

Answer 34

The point around which the entire weight of the body is evenly distributed

Question 35

Where is the centre of gravity in human

Answer 35

2 cm anterior to S2 on an upright body on the average male size/weight EXAM

Question 36

What does Centre of gravity depend on

Answer 36

Its dependent upon body build In women it’s lower due to the wider pelvic girdle and narrower shoulders