Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Intro to Biomechanics > Intro to Biomechanics > Flashcards

Intro to Biomechanics Flashcards

1
Q

Biomechanics definition

A
  • Application of mechanical laws to living structures

- Specifically to locomotor system of the human body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Walking definition

A
  • To move at a regular and fairly slow pace by lifting and setting down each foot in turn, never having both feet off the ground at once
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Less energy for walking is required when

A
  • There is minimal displacement of the center of mass

- Each moveable segment functions ideally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Series of movements in walking is orchestrated by

A
  • Stable joints
  • Muscle actions
  • Angular momentum
  • Sequential kinematic activity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Components creating joint stability

A
  • Bones and joints
  • Ligaments and joint capsule
  • Neuromuscular activity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Bones/joints contribution to stability

A
  • Shape of bones

- Design of articular cartilage in bones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Ligaments/joint capsulses contribution to stability

A
  • Provide resistance against ground reactive force
  • Prevent unwanted movement
  • Support desired joint position
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Neuromuscular activity contribution to stability

A
  • Types of muscular contraction
  • Agonist, antagonist dynamics
  • Joint proprioception
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Bones are designed functionally for

A
  • Shock absorption
  • Distribution of external stresses
  • Muscle attachments
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Osseous configuration of bone (examples)

A
  • Anterior lip of tibial plateau
  • Anterior medial aspect of calcaneus
  • Posterior cuboid
  • Lateral process of talus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Knee joint extension (stability)

A
  • Anterior lip of the medial facet of the tibia

- Prevents over-extension of the knee

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Calcaneocuboid joint (stability)

A
  • Excessive pronation inhibited by the dorsal “overhang” of the calcaneus
  • This creates a close-packed position
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Types of joints

A
  • Ball and socket
  • Condyloid
  • Saddle
  • Hinge
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Ligament influence on stabilization

A
  • Orientation/angulation

- Joints passed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Muscle contribution to joint stabilization

A
  • Agonist or prime movers
  • Antagonists
  • Stabilizers
  • Orientation to joint
  • Pennation
  • Type of tendinous insertion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Muscular role in joint movement

A
  • Prime mover
  • Antagonist
  • Synergist
  • Stabilizer
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Types of muscle contraction

A
  • Isometric

- Isotonic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Muscle architecture

A
  • Parallel
  • Pennate
  • Type of muscle fibers
  • Relation to joint axis
  • Shape of tendon
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Proprioception (“sense of self”)

A
  • Conscious: Dorsal Columns

- Unconscious: Cerebellar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Mediators of proprioception

A
  • Muscle spindle monitors muscle length
  • Golgi tendon organ monitors muscle tension
  • Pacinian corpuscle monitors pressure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Two basic requisites for walking

A
  • Continued ground reactive forces

- Periodic movement in the direction of progression

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Center of mass should remain

A
  • In the pelvis

- The body should NOT tip!!!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

To keep the center of mass within the pelvis

A
  • It “hovers” at constant height and minimally changing velocity
  • Decreased the energy required to walk
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Center of mass

A
  • The point where the distribution of mass is equal in all directions
  • It does not rely on gravitational pull
25
Q

Center of gravity

A
  • The point in a body where the forces of gravity vanish
  • This may depend on the vertical orientation of the body
  • The is the product of mass x gravity
26
Q

Center of gravity is located

A
  • 2 inches anterior to the second sacral vertebrae

- It follows vertical and horizontal displacement

27
Q

Center of gravity in anatomical position

A
  • Anterior to S2 vertebra
  • At ~ 56% of persons height
  • Shifts with body movements
  • Balance is dependent upon maintaining the COG above the feet
  • Body will compensate by bending and extending
28
Q

Vertical displacement

A
  • Up and down movement
  • Highest point: midstance
  • Lowest point: double support
  • Average displacement: ~ 5 cm
29
Q

Horizontal displacement

A
  • Side to side movement

- Lateral limit: midstance (~ 5 cm displacement)

30
Q

The gait cycle phases

A
  • Stance

- Swing

31
Q

Stance phase composed of

A
  • Contact
  • Midstance
  • Propulsion
32
Q

Contact (stance phase)

A
  • Foot/heel strike
  • Loading response ending with full forefoot load
  • Foot adapting to terrain and absorbing shock
33
Q

Midstance

A
  • Full forefoot load to heel off
  • Foot converting to rigid lever
  • Entire foot is on the ground
34
Q

Propulsion (stance phase)

A
  • Terminal stance
  • Heel off to toe off
  • Forward movement of the limb
35
Q

Swing phase composed of

A
  • Acceleration
  • Midswing
  • Deceleration
36
Q

Loading response

A
  • Foot becomes “unlocked” to become a mobile adaptor
  • Controlled flattening results in shock absorption
  • Limb is actively extending at the hip and knee
  • Ends with full forefoot load
37
Q

Propulsion (stance phase) accounts for

A
  • 33% of stance

- Pre-swing

38
Q

Pre-swing (propulsion)

A
  • Heel lift
  • Toe off
  • Foot off loaded
39
Q

During propulsion

A
  • Muscles working to “shorten” the limb to clear the ground
  • Hip and knee flexors
  • Dorsiflexion and inversion of foot and ankle
40
Q

Swing phase in open kinetic chain

A
  • Distal segment moves freely

- Divided into initial swing, mid swing, and late/terminal swing

41
Q

Initial swing

A
  • Limb is accelerating
42
Q

Late swing

A
  • Limb is decelerating

- Extending the limb for contact

43
Q

Six elements of gait

A
  • Pelvic rotation
  • Pelvic list
  • Knee flexion in stance phase
  • Ankle mechanisms
  • Foot mechanisms
  • Lateral displacement of body
44
Q

Pelvic rotation

A
  • Rotation about vertical axis
  • Transverse plane motion
  • Accomplished with flexion and extension of the hip
  • Rotation of ~4° on either side of axis
  • Increases with speed
45
Q

Swing leg during pelvic rotation

A
  • Rotates medially

- Rotation is 4° with double support

46
Q

Goal of pelvic rotation

A
  • Vertical adjustment

- The limbs are essentially lengthened without lowering the COM

47
Q

Pelvic rotation occurs with

A
  • Forward advancement of the swing limb

- Preparation for heel strike

48
Q

Pelvic list

A
  • Downward movement in the frontal plane

- Alternating hip movement

49
Q

Motions in pelvic list

A
  • Adduction in stance
  • Abduction in swing
  • ~ 5° angular displacement
50
Q

During pelvic list

A
  • There is a 5° dip on the swinging limb

- This reduces the height of the apex of the curve

51
Q

The 5° dip on the swinging limb during pelvic list occurs with

A
  • Adduction of the weight bearing limb

- Abduction of the swing limb

52
Q

Knee flexion in stance phase

A
  • Close to full extension
  • Flexes until the foot is flat on the ground (normally ~ 15)
  • Moves to extension with full weight bearing
  • Then… flexion with heel off
  • Elongates and shortens the limb
53
Q

Combination of pelvic rotation, pelvic list, and knee flexion during stance

A
  • Decrease vertical displacement of COM
  • Abrupt displacements still occur
  • Walking is still a series of arcs (not a smooth curve)
54
Q

Foot and ankle mechanisms

A
  • Two intersecting arcs of rotation
  • Hell contact
  • Heel rise
  • Together, smooth out the pathway
55
Q

Heel contact

A
  • Rotation of ankle about radius formed by heel
56
Q

Heel rise

A
  • Rotation of the forefoot
57
Q

Lateral displacement of the body

A
  • Side to side displacement
  • ~4-5 cm with each stride
  • Slight genu valgum keeps tibia vertical
58
Q

Lateral displacement is slightly increased when

A
  • Feet are further apart
59
Q

Lateral displacement is slightly decreased when

A
  • Decreased when feet are closer

Intro to Biomechanics (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions