Development of Locomotion

Question 1

what are the things that a child needs to walk independently

Answer 1

active/coordinate muscles and segments, have strength to support BW and stability for weight shift, and be able to adapt to different situations

Question 2

when does stance stability develop

Answer 2

end of 1st year -> beginning of second year

Question 3

when does adaptability develop

Answer 3

over the next few years after the start of independent walking

Question 4

how does progression develop from birth to the first year

Answer 4

birth has CPGs producing basic pattern and in the first year there is development of descending pathways to control it

Question 5

what is the stimulus for infant stepping behavior

Answer 5

hold them upright, lean them forward so COM is in front of LE

Question 6

when is the stepping behavior present/absent from birth to around 10 months

Answer 6

present from birth to 2 months, then disappears, and comes back around 10 months (walking age)

Question 7

what is the evidence that stepping behavior is from a CPG and changes in body systems lead to changes in stepping behavior

Answer 7

non stepping infants will step when immersed/unweighted, there are similarities between supine kicking and stepping patterns, yet kicking persists when stepping disappears

Question 8

what was the conclusion as to why babies stop stepping

Answer 8

due to increase in body mass and decrease in strength

Question 9

during early stepping and 1st independent steps, what kind of walking pattern do infants have

Answer 9

synchronous LE kinematics and lots of coactivation (hip flexion, kee flexion, and DF happen together)

Question 10

as walking matures, what kind of walking patterns do we see

Answer 10

asynchronous LE kinematics and coordinated LE muscle activity

Question 11

describe pendulum-like behavior of the LE

Answer 11

not innate, requires independent walking experience, active neural control, and coordinated coupling of LE kinematics, develops rapidsly

Question 12

what is the limiting factor for independent walking

Answer 12

postural control (and maybe strenght/force production in clinical pop)

Question 13

describe an infant (9-12mth) who is about to take their first steps

Answer 13

has motor coordination, vision, vestibular, and SS, motivation to move, and strength to support body in stance

Question 14

when do we consider gait to be adult like

Answer 14

7 years

Question 15

describe the initial stage of walking in developmental sequence

Answer 15

rigid, halting leg action, short steps, flat footed contact, out toeing, wide BOS, flexed knee at contact -> quick leg extension, etc,

Question 16

when infants perceive affordances for movement, is there carryover experience from position to position

Answer 16

no

Question 17

what is a critical determinant of independence and is an early/characteristic symptom of various disorders

Answer 17

impaired mobility functionw

Question 18

where in the gait cycle are spastic muscles often inappropriately activated

Answer 18

when they are being rapidly lengthened (velocity dependent)

Question 19

if spastic muscles have increased stiffness, what does that limit

Answer 19

intersegmental movements and limits progression during gait

Question 20

when do hampstrings activate to help decelerate the LE

Answer 20

late swing

Question 21

what can limit joint ROM throughout the gait cycle in children with CP

Answer 21

spasticity and stiffness in LE

Question 22

what happens with hip abductor weakness

Answer 22

pelvic drop (contralateral side) and compensation of lateral shift of COM overstance leg with lateral trunk lean

Question 23

what happens with hip flexor weakness

Answer 23

affects swing phase: poor toe clearance, shortened step length, and inadequate momentum to flex knee

Question 24

what are compensations of hip flexor weakness

Answer 24

posterior pelvic tilt, circumduction, contralateral vaulting, and lateral trunk lean

Question 25

what happens with quad weakness (MMT 3+-4)

Answer 25

difficulty controlling knee flexion during loading (early stance)

Question 26

what happens with quad weakness (0-3)

Answer 26

instability during midstance

Question 27

what compensations occur with quad weakness

Answer 27

forward trunk lean and knee hyperextension

Question 28

If someone's PF are weak, what happens during gait?

Answer 28

swing, toe clearance, and step length

Question 29

what compensations occur with PF weakness

Answer 29

increased hip/knee flexion, circumduction, and vaulting in swing (potential knee hyperextension with forward trunk lean in stance)

Question 30

if someone has PF spasticity, what happens in stance

Answer 30

resists forward motion of tibia, knee hyperextension and/or forward trunk lean, foot either flat or forefoot at initial contact

Question 31

if someone has has PF spasticity, what happens in swing

Answer 31

inadequate toe-off, toe drag occurs, and resistion of DF and knee extension (shortened step and decreased gait velocity)

Question 32

what is equinovarus

Answer 32

excessive PFs and posterior tibialis activity - initial contact with lateral forefoot

Question 33

what is equinovalgus

Answer 33

excessive PFs and peroneus brevis activity - inital contact with medial border of foot, can also result from weakness/inactivity of ankle invertors/flaccid paralysis

Question 34

if someone has quadriceps spasticity, what happens in early stance

Answer 34

excessive response to knee flexion, excessive knee extension through stance phase

Question 35

if someone has hamstring spasticity, what happens during swing or stance

Answer 35

prevents knee extension in swing - results in shortened step length, knee flexion persists through stance as well - crouched gait and short stride length

Question 36

If someone has hip adductor spasticity, what is seen in gait

Answer 36

scissoring gait, contralateral limb drop in pelvis (only spastic on one side), decreased BOS = decreased stability during gait

Question 37

what are some disordered patterns of muscle actviation seen in children with CP?

Answer 37

reduced muscle recruitment, inability to modulate activity, impaired intersegmental coordination, and non-stretch-related muscle overactivity

Question 38

why are agonist and antagonist muscle coactivated

Answer 38

pathologically disordanized central prgrams, disordered reciprocal innervation mechanisms, and compensatory PC behavior

Question 39

what is paresis

Answer 39

neuromuscular impairment resulting in inadequate force production (altered #, type, and discharge frequency of motor neuron recruitment)

Question 40

what can paresis affect

Answer 40

secondary changes in muscle fibers to alter ability to generate tension (nonneural) and insufficient supraspinal recruitment of motor neurons (neural)