Posture

Question 1

what is static posture? dynamic posture?

Answer 1

static is when the body and segments are aligned and still and this can predict dynamic (in movement)

Question 2

define postural sway

Answer 2

the body’s center of pressure corrals the CoM to maintain postural control via natural ocillations

Question 3

Clinical App: Increased postural sway can indicate decrease in stability and increased fall risk in what impairments?

Answer 3

hemiparesis
peripheral neuropathy
concussion
vestibular dysfunction 
pes planus

Question 4

what is the difference reactive and proactive postural control responses?

Answer 4

reactive Is a response to external destabilization whereas proactive is in anticipation of internally destabilizing forces

Question 5

describe the difference between the sensory and mechanical perturbations

Answer 5

sensory: altering sensory input (ex. blindfold, drunk goggles)
mechanical: displacement that changes the relationship between CoM and BoS (pushing, shaking)

Question 6

define ankle vs hip synergy/strategies.

Answer 6

ankle occurs distal to proximal and hip is in reverse–both in response to perturbation of standing posture.

Question 7

what are change in support strategies?

Answer 7

strategies that enlarge the BoS so that is still under CoM–the only successes vs large perturbations; includes stepping and grasping strategies.

Question 8

what contributes to internal force?

Answer 8

muscle activity and passive tension (joints, ligaments, and joint capsules)

Question 9

what contributes to external force?

Answer 9

inertia, gravity, and ground reaction forces

Question 10

describe the relationship between the LoG and a joint axis. what impacts the magnitude and direction of the external moment?

Answer 10

line passing through joint axis= no ext torque; outside of axis= external torque and rotation unless opposed by internal torque.
magnitude determined by distance between LoG and axis; direction determined by LoG location related to axis.

Question 11

what are 4 keys to success for a postural assessment?

Answer 11

assess multiple angles
remove obstructive clothing
observe multiple areas
be consistent in approach (always top down or vice versa )

Question 12

describe ideal alignment from a side view.

Answer 12

LoG passes through or very closely to all joint axis (ext meatus, shoulder, hip, knee, lat malleolus)

Question 13

describe ideal alignment from a posterior view.

Answer 13

through midline of head, spine and w/ feet evenly spaced

@ shoulder and scapula: flat on thorax between T2 and T7 apprx 4 in apart

Question 14

describe ideal alignment from an anterior view.

Answer 14

Knee: patellas fwd w/ slight valgus

ankles: neutral
feet: 3 in separation @ heel and about 8-10 degrees of out-toeing

Question 15

list the active contractors for each internal moment created at the knee hip and ankle for ideal posture

Answer 15

ankle- soleus and gastrocnemius
knee-hamstrings and gastrocnemius
hip-illiopsoas