Motor Development

Motor plan

overall strategy for movement

Motor Learning

"The study of how individuals acquire, modify, and retain motor memories so they can be used, reused, and modified during functional activities" (Umprhed, 2014). Four major points of motor learning -Learning is a process of acquiring the capability for skilled action -Learning results from practice or experience -Learning can't be measured directly -Learning produces relatively permanent changes in behavior Can be modified to adapt to a situation based on sensory feedback & conditions Generalization of skills occurs & child is able to use previously learned skills to decrease time and effort needed to learn a needed task 3 stages of motor learning -Cognitive stage/acquisition of a motor skill -Associative stage/refinement -Autonomous stage/retention

3 stages of motor learning

-Cognitive stage/acquisition of a motor skill -Associative stage/refinement -Autonomous stage/retention

Gait Heel strike develops at around __-__ months with reciprocal arm swing.

15-18

Gait After the age of __, running and change of direction occur.

2

Neonatal: Prematurity -Birth at less than __ weeks -Fetus considered viable at __ to __ weeks of gestation

37 22 to 23

Disassociation

Breaking up of this mass pattern; separating movement in one body part from an associated movement in another body part

Gait Adult gait and posture occur around the age of __ years.

8

Motor Skill

A motor skill is a learned sequence of movements that combine to produce a smooth, efficient action in order to master a particular task. The development of motor skill occurs in the motor cortex, the region of the cerebral cortex that controls voluntary muscle groups.

Equilibrium Reactions

Adjust for change in the body's orientation in space Comprised of righting reactions of head & trunk Protective extension responses of the extremities Include: -Tilting reaction -Protective responses in sitting & standing

Range of Motion in Pediatrics

Adult ROM values are NOT to be used for comparison with Newborn values. Full term newborns -Limited in hip and knee extension -Greater dorsiflexion than adults --Intrauterine position --Flexor muscle tone

Postural Reactions

Assist the child with orienting body in space in the upright position Develop in infancy to early childhood Include: -Righting Reactions -Protective Responses -Equilibrium Responses

Common Pediatric Gait Abnormalities -Spastic Gait

Associated with inversion of the foot and foot dragging. It occurs in diplegic and quadriplegic cerebral palsy and stroke.

Reflexes

Basic unit of movement in the hierarchical theory of motor control Involve the combination of a sensory stimulus & a motor response

Primitive Reflexes: Largely automatic, consistent, stereotypical A predictable motor response to a specific stimulus Emerge in the fetus & present at birth Provide an indication of the status of the ___ Circuitry is at the spinal cord or brain stem level Carried out w/o involvement of the ___ of the brain

CNS cortex

Common Pediatric Gait Abnormalities -Crouched Gait

Commonly seen in children with diplegic CP and hamstring contractures. Results in a combination of hip flexion, knee flexion, and ankle equinus (supination due to tone; walking on the outside of foot)

Cephalocaudal

Development occurs from head to toe Head is disproportionately larger than the other parts of the infant's body Describes the typical direction of development of postural responses Muscular control develops from the head downward -First the head & neck -Upper body and the arms -Lower trunk and the legs

Proximal to Distal

Development occurs from the center of the body outward (mid-line first to provide a stable base upon which the head & extremities may move) The head and trunk develop before the arms and legs, and the arms and legs before the fingers and toes Trunk is the stable base Not a cause-and-effect relationship between proximal and distal functions

Antigravity Flexion

Develops in supine first Foot-play, head lifting

Pediatric ROM Tendency for LE (born full term): 6 weeks -Hip EXT, ER, IR

EXT = 19 ER = 48 IR = 24

Pediatric ROM Tendency for LE (born full term): Birth -Hip EXT, ABD, ADD, ER, IR -Popliteal angle

EXT = 34.2 ABD = 55 ADD = 6.4 ER = 90 IR = 33 Popliteal angle = 27

Pediatric ROM Tendency for LE (born full term): 5 year -Hip EXT, ABD, ADD, ER, IR -Popliteal angle

EXT = 7 ABD = 54 ADD = 24 ER = 39 IR = 34 Popliteal angle = 0

Pediatric ROM Tendency for LE (born full term): 1 year -Hip EXT, ABD, ADD, ER, IR -Popliteal angle

EXT = 7 ABD = 59 ADD = 30 ER = 58 IR = 38 Popliteal angle = 0

Pediatric ROM Tendency for LE (born full term): 3 year -Hip EXT, ABD, ADD, ER, IR -Popliteal angle

EXT = 7 ABD = 59 ADD = 31 ER = 56 IR = 39 Popliteal angle = 0

Pediatric ROM Tendency for LE (born full term): 6 months -Hip EXT, ER, IR -Popliteal angle

EXT = 7 ER = 53 IR = 24 Popliteal angle = 11

Postural Reactions: Righting & Equilibrium Reactions

Emerge as primitive reflexes Emerge to help the infant or child cope with demands of a gravity-based environment Provide the basis for the control of automatic balance, posture and voluntary movement Are complex postural responses that continue to be present throughout adulthood

Physiologic Flexion

Full term babies are born in physiologic flexion Due to confinement & position in the womb Hip, knee & ankle flexion contractures

Lower Extremity Development

Genu varus, genu valgum & the normal growth process Normal children are typically born with genu varus because of their flexed position in the uterus -Increases until the age of 18 months, and then the legs straighten on their own. At age three or four, genu valgus develops -straightens by about age six, leaving the normal to slightly knock-kneed adult alignment.

Common Pediatric Gait Abnormalities -Toe Walking

Habitual toe-walking is not uncommon, and if asked the child can usually walk normally. Persistence of the symptom with failure of heel contact is seen in diplegic cerebral palsy or more rarely, a lysosomal storage disease.

Significance of Automatic Movements

Initial appearance demonstrates functioning subcortical primitive centers These early reflexes eventually diminish reflecting maturation of the nervous system with increased control of the cortex

Pediatric Gait Cycle - Swing Phase

Initial swing begins at toe off and continues until maximum knee flexion (60 degrees) occurs. Midswing is the period from maximum knee flexion until the tibia is vertical or perpendicular to the ground. Terminal swing begins where the tibia is vertical and ends at initial contact.

Gross to Fine

Large, mass movements occur Before refined, precise movements

Four major points of motor learning

Learning is a process of acquiring the capability for skilled action Learning results from practice or experience Learning can't be measured directly Learning produces relatively permanent changes in behavior

Pediatric Gait Cycle - Stance Phase

Loading response begins with initial contact, the instant the heel contacts the ground. Loading response ends with contralateral toe off, when the opposite extremity leaves the ground. Midstance begins with contralateral toe off, ends when the center of gravity is directly over the supporting foot. Terminal stance begins when center of gravity is over the supporting foot and ends when the contralateral foot contacts the ground. Pre-swing begins at contralateral initial contact and ends at toe off.

Postural Reactions -Protective Responses

Used in response to rapid displacement of the body as a result of an outside force Involve the movement of the extremities in the direction of the displacement

Variables Influencing Development (6)

Motivation Muscle strength Body weight Level of arousal Complexity & maturation of neural networks Environmental forces

Motor Control Strategies

Motor program - a set of pre-structured muscle commands that end up producing coordinated movement / learned task / carried out without influence of peripheral feedback Motor plan - overall strategy for movement Feedback - afferent information sent by sensory receptors to control centers with constant updates that allow for corrections shaping the ongoing movement & allows motor responses to be adapted to the demands of the environment Motor-skill acquisition - behavior is organized to achieve a goal directed task with active problem solving needed for the development of the motor program, plan, and learning & is adaptive to the specific demands of the environment CNS recovery - reorganization is dependent on experience - practice is required to regain lost skills, & ability to retain & generalize re-learned skill to other similar tasks or to apply in other environmental contexts Feed-forward - prepares the system in anticipation of responses required for movement and adjusts the system for incoming sensory feedback for future movements -Anticipatory (feed-forward) postural adjustments used by children with cerebral palsy and typically developing children to counteract self-generated motions that disturb balance.

Righting Reactions 1) Neck Righting, 2) Head Righting, 3) Trunk Righting 1) Optical Head Righting, 2) Labyrinthine Head Righting

Named to describe the body part responsible for the realignment & often mechanism for sending the signal Stimulus eliciting the response is the effect of gravity or position of the eyes regarding gravity

3 important elements of motor control

Neural circuit—underlies the processing of input/output Motor plan—effector of output of the neural circuit The environment in which movement occurs—shapes the play between the neural circuit & the motor plan

Automatic Movements

Occur in response to a stimuli & often involuntarily Include: -Reflexes -Postural Reactions --Righting reactions = movement of the head following with eyes --Equilibrium reactions --Protective reactions --Associated reactions

Postural Reactions -Righting Reactions

Orient the head & body in space Involve head & trunk movements

Abnormal Reflexes

Persistent, abnormal, or asymmetrical usually indicate early brain damage and will affect future normal development

Gait Considerations

Physical therapy for children with gait problems focuses on implementing mobility and strengthening programs, overseeing orthotic use through open communication with their physician and orthotist, balance training, and gait training

Kinesiological Concepts

Physiologic Flexion Antigravity Extension Antigravity Flexion Lateral Flexion Rotation Mobility & Stability Asymmetry to Symmetry to Controlled Asymmetry Weight Bearing & Weight Shifting Rotation/Dissociation

CNS recovery

Reorganization is dependent on experience - practice is required to regain lost skills, & ability to retain & generalize re-learned skill to other similar tasks or to apply in other environmental contexts

Primitive Reflexes: Summary (read)

Serve some sort of movement purpose Slowly inhibited during the first year of life Ensure the baby's survival in early months of life & provide a training platform for many later voluntary skills Should have a short life-span & should be inhibited or controlled by higher centers of the brain Functionally, contribute to the development of emerging mobility

Common Pediatric Gait Abnormalities (5)

Steappage Gait, Spastic Gait, Trendelenberg Gait, Toe walking, Crouched Gait

Motor Control

Study of how the CNS regulates the musculoskeletal system and environment in regard to movement for the attainment of a specific task 3 important elements of motor control -Neural circuit—underlies the processing of input/output -Motor plan—effector of output of the neural circuit -The environment in which movement occurs—shapes the play between the neural circuit & the motor plan Stresses task specific learning - all movements are goal oriented Takes into account both neuromuscular control processes & environmental constraints

Common Pediatric Gait Abnormalities -Steppage Gait

The entire leg is raised at the hip to ensure adequate ground clearance (a foot drop gait). It can be seen with peripheral neuropathies, spina bifida and polio.

Motor Development

The study of changes in human motor behavior over the lifespan, the process that underlie these changes, and the factors that affect them (Umphred, 2014) All periods of development are valued equally Dynamic, nonlinear process with periods of stability and instability Influenced by intrinsic and extrinsic factors Important as a PTA to understand this process for proper assessment and intervention of impairment/functional challenges encountered at any age stage

Postural Reactions -Equilibrium Responses [aka - Labyrinthine Reactions]

Used when there are slow changes occurring between the center of gravity and the base of support Degree of displacement determines the response used -Beginning with the head -Then the trunk -Then the shoulder & or hip abduction if the displacement is great enough

Righting Reactions

Thought to be mediated at midbrain level in response to signaling from several different sensory receptors including: -Proprioceptors, cutaneous receptors, eyes and labyrinth of the ears Realigns the head or trunk with each other or with an outside stimulus

Common Pediatric Gait Abnormalities -Trendelenberg Gait

Typically caused by weakness of the hip abductors. The feet, hips and knees are externally rotated, and when weight is borne on one leg, the opposite side of the pelvis drops, rather than rising as normal. Commonly seen in slipped capital femoral epiphysis, Legg-Calve-Perthes disease (idiopathic osteonecrosis of the femoral head), hip dysplasia and inherited myopathies, as well as spina bifida and cerebral palsy. If bilateral sides are affected, the patient exhibits a rolling gait.

Primitive Reflexes

Typically present at birth Normal for young infants Usually integrated in the first 9 months of life

Antigravity Extension

Voluntary, active movement against gravity First seen at the neck then the trunk In prone, begins with lifting of the head In prone, extensors strengthen & flexion contractures decrease

When Alignment is NOT Normal When not a part of normal development, bow-legs are a symptom of a disease or injury such as (5)

When not a part of normal development, bow-legs are a symptom of a disease or injury such as... Problems with metabolism Problems with nutrition Fractures that heal incorrectly Rickets or Blounts Disease Genetic bone growth abnormalities

Undifferentiated to Specific

Whole body movements develop before selective movement & before disassociation occurs

Motor program

a set of pre-structured muscle commands that end up producing coordinated movement / learned task / carried out without influence of peripheral feedback

Feedback

afferent information sent by sensory receptors to control centers with constant updates that allow for corrections shaping the ongoing movement & allows motor responses to be adapted to the demands of the environment

Motor-skill acquisition

behavior is organized to achieve a goal directed task with active problem solving needed for the development of the motor program, plan, and learning & is adaptive to the specific demands of the environment

Gait Toddlers have a _____-based gait for support, and appear to be high-stepped and flat-footed, with arms outstretched for balance. Legs are externally rotated, with a degree of bowing.

broad

SOME Warning Signs of Developmental Delay -Behavioral (2)

daily violent behavior rocks body

SOME Warning Signs of Developmental Delay -Gross motor (2)

has stiff arms and legs clumsy compared to same age children

Gait School-aged children, demonstrate a step length ____ and step frequency ____.

increase slows

Warning Signs of a Developmental Delay There are many types of developmental delays. Some areas include problems with: (5)

language or speech vision movement -- motor skills social and emotional skills thinking -- cognitive skills

Feed-forward

prepares the system in anticipation of responses required for movement and adjusts the system for incoming sensory feedback for future movements -Anticipatory (feed-forward) postural adjustments used by children with cerebral palsy and typically developing children to counteract self-generated motions that disturb balance.

Primitive Reflexes: Older children or adults with atypical neurology may..... IE: patients with cerebral palsy If there is a cluster of primitive reflexes remaining, CNS will be ______ in some way Primitive reflexes may reappear in adults b/c of certain neurological conditions including, but not limited to (3)

retain these reflexes dysfunctional Dementia, Head Trauma, Strokes

SOME Warning Signs of Developmental Delay -Visual (2)

rubs eyes frequently brings objects too close to eyes to see

Lower Extremity Development Normal children are typically born with genu ____ At age three or four, genu _____ develops

varus valgus

Gait 3 yrs. of age is when a child's gait pattern begins to resemble that of an adult. Initially there is a ____-based stance with ___ cadence and ___ steps.

wide rapid short