Lecture 13: posture response triggers

Question 1

Proposed origins of primary trigger for postural response?

Answer 1

• Ankle proprioceptors
• hip and trunk proprioceptors
• vestibulo-spinal
• load receptors
  look at onset latency (100-120ms after)

Question 2

what did allen et. al. look into

Answer 2

enhanced ankle angle protocol
looked at emg of those with lower leg and total leg proprioceptive loss

Question 3

What did allen et al find

Answer 3

argued that potentially proximal joint proprioceptive info does play a role in triggering postural responses

Question 4

nulled ankle angle protocol

Answer 4

conducted by allen et al
kept original angle of ankle the same so that theoretically proprioceptive information is no longer there
still see normal balance correcting responses (NOT CRITICAL FOR RESPONSES)
still evidence that more proximal joints providing cues

Question 5

is vestibular information critical for balance correcting responses?

Answer 5

No, no delays that would indicate so
vestibular information still responsible for modulating appropriate amplitude of responses

Question 6

load receptors and postural correction

Answer 6

detect load on muscles
Deitz et. al.
EMG slightly reduced when load of receptors was decreased
no delays seen
not critical

Question 7

Is vision critical for postural responses

Answer 7

no
Nakata and Yabe 2001, observed eyes open and closed
same timing of response, no change in onset latency
blind, same or slightly shorter onset latency

Question 8

Is there reduncancy in sensory feedback to trigger postural responses?

Answer 8

yes

Question 9

Conditioned postural responses

Answer 9

Campbell et. al.
loud auditory cues stimulus
response is the balance correcting response when the platform would move
response

Question 10

results of postural conditioning

Answer 10

less amplitude seen when tone was provided
postural responses can occur without normal sensory cues, such as the platform moving

Question 11

Postural responses can be ___ for an extended time

Answer 11

stored, pavlovian style trial conducted by campbell et al

Question 12

startling response ___ balance correcting response that is _____

Answer 12

stimulates, prepared

Question 13

Postural responses can be prepared even with _____ ___ or ______ ____

anticipation

Answer 13

limited physical, visual experience