L7 Walking through the lifespan

Question 1

history: transected spinal cords cats

Answer 1

cats w transected spinal cords have same muscle activity
lower limb activity activated under certain circumstances

Question 1

history: constraint induced/forced use

Answer 1

monkey studies, 68
rehab limb by engaging it in activties

Question 2

history: neural control of walking

Answer 2

higher brain centers not needed to walk
removing sensory information, walking pattern still remains

Question 3

infant stepping pattern

Answer 3

kick in utero
at birth stepping pattern
disappear at 2 months
reappears at start of walking

Question 4

progression from stability to mobility as an infant

Answer 4

stand w assistance
mobility w two hands support
stand alone
independent mobility

Question 5

time of emergence for gait

Answer 5

walk without assistance 9-15 months
motor delay if walking not occurring at 18 mo
myelination reaches LE at 9 months, caudal to distal

Question 6

components of gait factors as infant

What skills do infants develop in first 12 months to progress to gait?

Answer 6

developed from birth to 12 mo
locomotion pattern/CPG
postural control
motivation/navigate towards object
stand on one leg in stance
high guard posture

Question 7

components necessary for gait emergence

Answer 7

motor production
cpg
dissociation of limbs
balance/postural control
intact sensory system
myelination

Question 8

sensory contributions to gait

Answer 8

vision: balance, steer, avoid
optic flow
stabilize head with vertical vision
vestibular: stabilize head
posture
sensory/proprioception: feedback for body awareness

Question 9

characteristics of first steps

Answer 9

high step
wide base
no push off
knee flexed in stance
no arm swing
high guard
synchronized patterns in legs
waddling

Question 10

joint synchronization

Answer 10

joints tend to move together/simultaneously rather than individually

Question 11

early walking posture

Answer 11

forward center of mass

Question 12

early progression of gait

Answer 12

control equilibrium responses
control single limb stance
change directions
heel strike
gait matures at 3-7 years old

Question 13

walking skills

infant

Answer 13

avoid obstacles
protective responses
distance
navigation
cognitive processing

Question 14

sensory contributions to gait

specific

Answer 14

stretching of hip flexors - propels limb forward with trailing limb stance
step length at appropriate frequency
pressure sensors in loading limbs

Question 15

how does muscle change with age?

Answer 15

lose after age 60, esp type 2
reduced muscle mass = sarcopenia

Question 16

sarcopenia vs muscle atrophy

Answer 16

muscle atrophy from disuse is a reduction in muscle synthesis with normal breakdown
sarcopenia is a decrease in muscle building on top of an increase in breakdown

Question 17

vertebral changes with age

Answer 17

lose vertebral height in body, creating forward stooped posture

Question 18

aging causes loss of what senses

Answer 18

tactile: lose fine touch, heat/cold, pain
vision: acuity, distance
vestibular: acceleration, head rotation speed and movement

Question 19

Why do elderly need vestibular?

Answer 19

response to protect head when falling
use ankle/hip strategies, arm extension/parachute

Question 20

decline in gait speed associated with

Answer 20

aging
dementia - reduced cognitive incline to walk