Posture

Question 1

Static Posture

Answer 1

Body and its segments are aligned and maintained in certain positions

Question 2

Dynamic Posture

Answer 2

Postures in which the body or segments are moving

Question 3

Base of Support (BOS)

Answer 3

Area enclosed by the outermost edges of the body in contact with the supporting surface

Question 4

Where is your typical center of mass during static posture?

Answer 4

Just anterior to s1 or s2

Question 5

Using an assistive device ___________ the BOS, providing _________________________

Answer 5

increases

more postural stability

Question 6

Postural Control

Answer 6

person’s ability to maintain stability of the body and body segments in response to postural threats

Question 7

How do you maintain postural control? (3)

Answer 7

Maintaining COM within BOS

Control body’s orientation in space

Maintaining erect posture requires integration of CNS and PNS

Question 8

Define Postural Sway

Answer 8

oscillations in COM occurring in A/P and M/L direction

COP (center of pressure) corrals COM to maintain postural control

Question 9

Increased postural sway indicative of _________ postural control challenge… what does this do?

Answer 9

Increased

Decreased stability: Increased risk for falls due to difficulty keeping COM within BOS

Question 10

What can increase sway?

Answer 10

Hemiparesis 
Peripheral neuropathy 
Concussion
Vestibular dysfunction 
Pes Planus

Question 11

Reactive (compensatory) response in postural control are…

Answer 11

Responses occur as reactions to external destabilizing forces

Question 12

Proactive (anticipatory) responses in postural control are…

Answer 12

Responses occur in anticipation of internally destabilizing forces

Question 13

Posture may be altered and stability may be compromised with…

Answer 13

altered or absent inputs

I.e. Decreased sensation of the lower extremities or post-injury

Question 14

Alterations in outputs also compromise posture. What does this mean?

Answer 14

inability of muscles to respond appropriately to signals from CNS due to a neuromuscular disorder

Question 15

In a normally functioning CNS, we will select the most efficient combination of muscles to completely the task after analyzing _______________. This creates ________________.

Answer 15

Sensory input

Dynamic control

Question 16

Sensory Perturbation: may be caused by _____________________________

Answer 16

altering sensory input

Question 17

Mechanical Perturbation: displacement causing changes in the relationship of the body’s ____________________

Answer 17

CoM to

BoS

Question 18

Muscle strategies are centrally organized patterns of muscle activity that occur in response to…

Answer 18

Perturbations of standing postures

Question 19

Describe ankle strategies/synergy

Answer 19

Discrete bursts of muscle activity that occur in a distal-to- proximal pattern

Question 20

Describe hip synergy/strategy

Answer 20

Discrete bursts of muscle activity that occur in a proximal-to-distal pattern

Question 21

Alternate Balance Strategies

Answer 21

move or enlarge the body’s BOS so that it remains under the COM

Only strategies that are successful with a large perturbations

Question 22

Stepping strategies involve taking steps in what directions

Answer 22

Forward
Backward
Lateral

Question 23

Grasping strategies are

Answer 23

Using one’s hands to grab on a fixed surface

Question 24

What is the normal recruitment of postural control strategies occurring from small perturbations to large perturbations?

Answer 24

Ankle > hip > stepping > grasping

Question 25

Ground Reaction Force (GRF)

Answer 25

Force of the ground pushing back on the body in standing

Question 26

Line of Gravity (LOG)

Answer 26

Extending from COM to the base of support

Question 27

Center of Pressure (COP)

Answer 27

Point of application of the GRF | Located between the feet in bilateral stance

Question 28

If LOG passes through a joint axis:

Answer 28

No torque created around the joint

Question 29

If LOG passes outside the joint axis

Answer 29

External gravitation moment | Results in rotation around the joint axis unless it is opposed by a counterbalancing internal moment

Question 30

Magnitude of the external moment ___________ as the distance between the LOG and joint axis increases

Answer 30

Increases

Question 31

Direction depends on the location of the ______ in relation to the joint axis

Answer 31

LOG

Question 32

Goals of postural assessment

Answer 32

Appreciate static positioning of body segments with relation to each other Relate back to patient’s main complaints Apply to potential functional impairments

Question 33

Keys to success for a postural assessment

Answer 33

Assess from multiple angles Remove obstructive clothing Observe more than the area of complaint

Question 34

Where is the LOG in ideal standing posture? Why?

Answer 34

LOG passes through or very close to all joint axes Minimizes external moments External moments are balanced by internal moments

Question 35

Long term deviations to standing posture result in

Answer 35

Structural changes

Question 36

Where is the LOG passing through in ideal standing posture from the side view

Answer 36

. Slightly posterior to the apex of the coronal suture • Through the external auditory meatus* • Through the odontoid process of the axis • Midway through the shoulder* • Through the bodies of the lumbar vertebrae • Through the sacral promontory • Slightly posterior to the center of the hip joint* • Slightly anterior to the axis of the knee joint* • Slightly anterior to the lateral malleolus* • Through calcaneocuboid joint

Question 37

LOG is anterior to knee joint axis | External moment:

Answer 37

extension Possible additional extension moment contributed by soleus contraction

Question 38

LOG passes slightly anterior to lateral malleolus | Creating an external moment of

Answer 38

Dorsiflexion

Question 39

To maintain static posture the internal moment of the ankle is..

Answer 39

Plantarflexion | By Active contraction of soleus, with contribution from gastrocnemius

Question 40

To maintain static posture, the internal moment of the knee is… How?

Answer 40

flexion Prevents knee hyperextension via… Passive tension of posterior joint capsule and associated ligaments Active contraction of: hamstrings & gastrocnemius

Question 41

LOG passes slightly posterior to axis of hip | External moment:

Answer 41

extension At times, postural sway may cause LOG to pass anterior and create flexion moment

Question 42

To maintain static posture the internal moment at the hip is… How?

Answer 42

flexion Passive tension of hip ligaments Active contraction of iliopsoas

Question 43

LOG passes through the body of L5. external moment:

Answer 43

slight extension moment Creates shear force rather than true torque

Question 44

What opposes the external moment at L5 to maintain a static posture

Answer 44

Opposed by anterior longitudinal ligament, iliolumbar ligaments, facet joint approximation

Question 45

LOG passes through external auditory meatus, anterior to axis for head External moment:

Answer 45

Flexion of c-spine

Question 46

To maintain a static posture at the head and neck, the internal moment is… How?

Answer 46

extension of c-spine Passive tension of ligamentum nuchae, tectorial membrane and posterior facet joint capsules Active contraction of cervical extensors

Question 47

When assessing standing posture in the posterior/anterior view, you are looking for

Answer 47

symmetry of the head, spine and feet And Scapulae lie flat on the thorax, Approximately between T2 and T7, and 4 inches apart

Question 48

What is ideal posture of the knees in the anterior view

Answer 48

Patellae face directly forward | Slight physiological valgus

Question 49

What is the ideal alignment of the ankles from the anterior view

Answer 49

Neutral (no supination or pronation)

Question 50

What is the ideal alignment of the feet from the anterior view

Answer 50

Heels separated about 3 inches | Out toeing 8-10 deg