Brainscape's Knowledge GenomeTM

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


See full index

Unit 3 Biomechanics Winter 2024 > Posture & balance > Flashcards

Posture & balance Flashcards

1
Q

What is the difference between static & dynamic posture?

A

Static:
- body is aligned and maintained in certain positions (standing, sitting, kneeling)

Dynamic:
- body is moving (walking, running, lifting)

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

Explain the relationship between CoM, LoG, and BoS

A
  • LoG must stay w/in BoS or individual will fall
  • Higher CoM = LoG outside BoS = less stable
  • Lower CoM = LoG stays inside BoS = more stable
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Does CoM move towards or away from weight added?

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

How does reactive postural control differ from proactive postural control?

A

Reactive:
- compensatory
- “reacts” to the external forces

Proactive:
- anticipatory
- getting ready for the external forces

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

What are the 3 systems responsible for postural control?

A
  • vestibular
  • vision
  • somatosensory (proprioceptors in joints, ligaments, tendons, muscles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the goals of control?

A
  • control body’s spatial orientation
  • keep CoM over BoS
  • stabilize head vertically for gaze
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Why is a person likely to re-sprain an ankle after the initial sprain injury?

A
  • ankle lacks ability to detect PROM & less stable
  • lack of input for proprioception
  • can’t detect input = less ability to be reactive/proactive
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is an example of sensory perturbations?

A
  • altering vision input
  • closing eyes/ears w/ balance training
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is an example of mechanical perturbations?

A
  • cause direct changes in CoM to BoS relationship
  • arm locked in a position then external force pushing/pulling the arm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the anti-gravity postural muscles?

A
  • Neck & back extensors (erector spinae)
  • hip & knee extensors (glutes)
  • Neck & trunk flexors (abdominals)
  • hip abductors & adductors (TFL, glute med)
  • DF’s & PF’s (gastroc/soleus, tib anterior)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe the type of postural synergy or strategy for the ankle, hip, and stepping when it comes to size of perturbation

A

Ankle:
- small

Hip:
- large

Stepping:
- very large

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

Describe the type of postural synergy or strategy for the ankle, hip, and stepping when it comes to order of muscle activation

A

Ankle:
- posterior displacement = tib ant., quads, abs
- anterior displacement = gastroc, hamstrings, para spinals

Hip:
- Posterior displacement = abs, quads, tib ant.
- Anterior displacement = para spinals, hamstrings, gastroc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe the type of postural synergy or strategy for the ankle, hip, and stepping when it comes to sequence of strategies with increasing perturbation

A

Ankle:
- distal to proximal

Hip:
- proximal to distal

Stepping:
- widens BoS
- younger take 1 step
- older take multiple

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe the type of postural synergy or strategy for the ankle, hip, and stepping when it comes to typical scenarios for each strategy

A

Ankle:
- leaning forward/backward & keeping balance

Hip:
- balancing on a board/tightrope

Stepping:
- falling over & taking a step to catch yourself

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

What is postural sway?

A
  • body’s constant swaying motion
  • sagittal = 12 degrees
  • frontal = 16 degrees

Limit of Stability (LoS) = edge of the sway envelope

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How does the CoP relate to the LoG & GRF?

A
  • CoP is the center where the force is put through a surface
  • the closer the CoP, LoG, & GRF’s are to each other the more balanced an individual will be
  • less sway will occur
17
Q

Explain the difference between External and internal moments as it relates to posture

A

External:
- gravity; a moment increases as the LoG moves further away from the joint

Internal:
- muscles; counteract the gravitational moment which puts less stress on the joint

18
Q

Describe where the LoG should fall from head to toe for optimal postural alignment

A

Frontal plane:
- through external auditory meatus (as close to the joints as possible to the ankle)

Sagittal plane:
- make 2 completely symmetric halves

19
Q

What are the consequences of prolonged postural deviations, even small ones?

A
  • body doesn’t recognize faulty postures as abnormal over time
  • muscles shortening/lengthening = alters length-tension relationship
  • ligament shortening = limits ROM
  • ligament lengthening = unstable joints
  • cartilage degeneration from improper weight bearing on joint surfaces
20
Q

Discuss the consequences of flexed knee posture

A
  • LoG moves to posterior to knee
  • causes quads to produce an external force (fatigues too fast)
  • fall risk
  • patellofemoral joint stress
  • causes hip extensors to produce an external force
  • increases soleus activity to combat DF moment
21
Q

Discuss the consequences of genu recurvatum

A
  • knee hyperextension beyond neutral (LoG anterior)
  • posterior capsule under a lot of tension
  • unstable knee
  • increases compression in anterior knee
  • length-tension relationship altered which could affect muscles ability to change this
22
Q

Discuss the consequences of anterior pelvic tilt

A
  • lower lumbar vertebra move anterior
  • upper lumbar vertebra move posterior
    this increases lordosis in lumbar/cervical regions and kyphosis in thoracic region
  • increases compressive forces on annulus = less nutrition
  • increases compression at facet joints
23
Q

Discuss the consequences of posterior pelvic tilt

A
  • spine flattens out = less flexibility
  • decreases lumbar spine’s ability to withstand high loads
24
Q

Discuss the consequences of thoracic kyphosis (exaggerated)

A
  • increases compression on thoracic vertebral bodies
  • LoG anterior = increases IMA
  • posterior tensile stress increases
  • decreases force generating capacity of back extensors
  • soft tissue creep
25
Q

Discuss the consequences of forward head posture

A
  • facet & disc compression
  • foraminal narrowing
  • extensor ischemia
  • facet capsules shortened
  • nerve root compression
  • TMJ altered
  • scapular IR
  • thoracic kyphosis
  • decreased vital capacity
26
Q

Explain proper sitting posture as if you were talking to a patient

A
  • sitting upright, flatten your back, chest up tall
27
Q

Why is proper sitting posture so important?

A
  • decreases compression on discs & helps decrease the risk of altering length-tension relationship of muscles/ligaments
28
Q

What is the best sitting position to decrease pressure on the intervertebral discs?

A
  • seat reclines b/w 110-130
  • lumbar support about 5cm from chair
  • posterior seat inclined about 5 degrees
  • arm rest help w/ reduction
29
Q

What are the 4 types of sitting?

A
  • active erect sitting
  • relaxed erect sitting
  • slumped sitting
  • slouched sitting
30
Q

How does pregnancy affect posture?

A
  • CoM changes
  • increased cervical & lumbar lordosis
  • shoulder girdle protraction
  • knee hyperextension

Unit 3 Biomechanics Winter 2024 (8 decks)

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