Development of Locomotion Flashcards
what are the things that a child needs to walk independently
active/coordinate muscles and segments, have strength to support BW and stability for weight shift, and be able to adapt to different situations
when does stance stability develop
end of 1st year -> beginning of second year
when does adaptability develop
over the next few years after the start of independent walking
how does progression develop from birth to the first year
birth has CPGs producing basic pattern and in the first year there is development of descending pathways to control it
what is the stimulus for infant stepping behavior
hold them upright, lean them forward so COM is in front of LE
when is the stepping behavior present/absent from birth to around 10 months
present from birth to 2 months, then disappears, and comes back around 10 months (walking age)
what is the evidence that stepping behavior is from a CPG and changes in body systems lead to changes in stepping behavior
non stepping infants will step when immersed/unweighted, there are similarities between supine kicking and stepping patterns, yet kicking persists when stepping disappears
what was the conclusion as to why babies stop stepping
due to increase in body mass and decrease in strength
during early stepping and 1st independent steps, what kind of walking pattern do infants have
synchronous LE kinematics and lots of coactivation (hip flexion, kee flexion, and DF happen together)
as walking matures, what kind of walking patterns do we see
asynchronous LE kinematics and coordinated LE muscle activity
describe pendulum-like behavior of the LE
not innate, requires independent walking experience, active neural control, and coordinated coupling of LE kinematics, develops rapidsly
what is the limiting factor for independent walking
postural control (and maybe strenght/force production in clinical pop)
describe an infant (9-12mth) who is about to take their first steps
has motor coordination, vision, vestibular, and SS, motivation to move, and strength to support body in stance
when do we consider gait to be adult like
7 years
describe the initial stage of walking in developmental sequence
rigid, halting leg action, short steps, flat footed contact, out toeing, wide BOS, flexed knee at contact -> quick leg extension, etc,
when infants perceive affordances for movement, is there carryover experience from position to position
no
what is a critical determinant of independence and is an early/characteristic symptom of various disorders
impaired mobility functionw
where in the gait cycle are spastic muscles often inappropriately activated
when they are being rapidly lengthened (velocity dependent)
if spastic muscles have increased stiffness, what does that limit
intersegmental movements and limits progression during gait
when do hampstrings activate to help decelerate the LE
late swing
what can limit joint ROM throughout the gait cycle in children with CP
spasticity and stiffness in LE
what happens with hip abductor weakness
pelvic drop (contralateral side) and compensation of lateral shift of COM overstance leg with lateral trunk lean
what happens with hip flexor weakness
affects swing phase: poor toe clearance, shortened step length, and inadequate momentum to flex knee
what are compensations of hip flexor weakness
posterior pelvic tilt, circumduction, contralateral vaulting, and lateral trunk lean
what happens with quad weakness (MMT 3+-4)
difficulty controlling knee flexion during loading (early stance)
what happens with quad weakness (0-3)
instability during midstance
what compensations occur with quad weakness
forward trunk lean and knee hyperextension
If someone’s PF are weak, what happens during gait?
swing, toe clearance, and step length
what compensations occur with PF weakness
increased hip/knee flexion, circumduction, and vaulting in swing (potential knee hyperextension with forward trunk lean in stance)
if someone has PF spasticity, what happens in stance
resists forward motion of tibia, knee hyperextension and/or forward trunk lean, foot either flat or forefoot at initial contact
if someone has has PF spasticity, what happens in swing
inadequate toe-off, toe drag occurs, and resistion of DF and knee extension (shortened step and decreased gait velocity)
what is equinovarus
excessive PFs and posterior tibialis activity - initial contact with lateral forefoot
what is equinovalgus
excessive PFs and peroneus brevis activity - inital contact with medial border of foot, can also result from weakness/inactivity of ankle invertors/flaccid paralysis
if someone has quadriceps spasticity, what happens in early stance
excessive response to knee flexion, excessive knee extension through stance phase
if someone has hamstring spasticity, what happens during swing or stance
prevents knee extension in swing - results in shortened step length, knee flexion persists through stance as well - crouched gait and short stride length
If someone has hip adductor spasticity, what is seen in gait
scissoring gait, contralateral limb drop in pelvis (only spastic on one side), decreased BOS = decreased stability during gait
what are some disordered patterns of muscle actviation seen in children with CP?
reduced muscle recruitment, inability to modulate activity, impaired intersegmental coordination, and non-stretch-related muscle overactivity
why are agonist and antagonist muscle coactivated
pathologically disordanized central prgrams, disordered reciprocal innervation mechanisms, and compensatory PC behavior
what is paresis
neuromuscular impairment resulting in inadequate force production (altered #, type, and discharge frequency of motor neuron recruitment)
what can paresis affect
secondary changes in muscle fibers to alter ability to generate tension (nonneural) and insufficient supraspinal recruitment of motor neurons (neural)
