Week 5 Flashcards
What is the purpose of reflex testing?
Diagnostically, reflex testing is used to:
* 1. Determine the gestational age of an infant
* 2. Determine the developmental “age” of a subject
* 3. Assess the development and integrity of the CNS
* 4. Determine the integrity of peripheral nerves
* 5. Plan and implement short and long-range treatment based on the inter-relationships between motor development and reflex development
Describe the relationship between gestational and developmental age
- Some reflexes emerge prior to 40 weeks gestational age. If a baby is born prematurely, they should have some of those reflexes, and that will help the neonatologist to know the infant’s approximate age
- That, combined with other reflexes and motor assessment findings, can help them to pinpoint the premature infant’s gestational age.
- Knowing when the reflexes are present or are integrated, when reactions become present, as well as other motor skills attained, will help us to determine the developmental age or “age equivalent” of an infant or young child.
How do you assess the integrity of CNS?
Reflex testing
- Weak/absent or exaggerated
- Asymmetrical (Never want automatic movements to be asymmetrical-Red Flag)
- Persists past the expected time of integration
- Obligatory (movement is dominated by the reflex) vs Habituation
What are the types of reflexes?
1) Primitive reflexes/automatic movement patterns
2) righting reflexes
3) equilibrium reactions
Describe Primitive reflexes/automatic movement patterns
- Infants are born with some stereotypical movements referred to as primitive or neonatal reflexes/movements that appear during gestation or at birth and are integrated by 6 months.
- Their function is primarily protective or to initiate some immature movements.
- The receptors are primarily tactile.
- For example, think of the rooting reflex. The rooting reflex is elicited when we stroke the baby’s face, and the response is that the baby turns their head /face toward the stimulus, in search of a food source. The stroking of the face is the tactile input/stimulus.
What are some considerations for reflex testing?
- There must be a specific, accurate stimulus given.
- Adequate time must be allowed for a response to occur due to polysynaptic and segmental involvement.
- Responses may not always be full-blown or readily visible. Palpation may be needed to detect an emerging or minimal response.
*When a child is ‘outgrowing’ the age range when reflexes might be present, we need to allow enough time to view the response, and/or passively move an extremity to see if we can feel the impact of flexion, extension, etc. on the limb. It is not always that reactions are observed, but sometimes must be felt.
What are some considerations for reflex testing? (Pt 2)
- Reflexes provide the foundation and prefabricated blocks upon which
volitional movement is built; however, individual responses must always
be correlated with each other and the assessment to determine their
significance. - Age ranges are only guidelines as normal development varies greatly (we
will talk about this more in other modules). The reflex performance of a
client is also dependent on internal factors such as their arousal state
(happy? crying? sleepy?), hunger, thirst, and body temperature. - External factors such as variations in head/limb position, environmental
temperature and clothing may also affect the response. - Finally, the role of the various portions of the brain in modifying reflexes and coordinating their integration is still under investigation
What are the components of postural reflex/reactions?
- Postural Tone
- Righting Reactions
- Protective Extension Reactions
- Equilibrium Reactions
- Tilting Reactions
- Postural Fixation Reactions
Describe postural tone
- When the weight of the body is put on a limb, the muscles automatically
contract; contraction/tone must be high enough to resist gravity, but low
enough to permit the intended movement in a controlled manner. - Tone changes during course of development. It develops gestationally (prior to birth) beginning with higher tone distally.
- At term birth, tone is initially lower proximally relative to distal body parts (i.e. hand grasp is seen in newborns, indicating higher baseline tone); it is also higher in UE’s relative to lower extremities.
- In mature distribution (adults), tone is higher proximally relative to distal tone; this provides proximal stability while allowing free movements distally (hands, feet). Additionally, mature tone is higher in LE’s relative to UE’s (perhaps due to more weight bearing requirements).
What are the types of righting reactions?
1) Neck righting–if the head is turned, the body will re-align with the
head. This changes with age: in neonates, it involves rotation at
neck, but after 4 mos. of age, we see the rotation between the
pelvis and shoulders as well.
2) Head righting–head assumes normal position in space with the
mouth horizontal and face vertical.
3) Body righting–rotational movements which realign the body part if it is displaced in relation to the other body parts. This can be body on
head righting (if the body is rotated, the head tends to follow the body), or body on body righting (if the pelvis is rotated, the shoulders will tend to follow the pelvis, though it is also
demonstrated when the pelvis follows the shoulders).
Describe righting reactions
- These are automatic reactions which bring the head and trunk into
normal alignment to each other and enable man to get into the upright
posture. - These reactions appear in infancy or childhood and persist throughout life.
- The receptors are primarily vestibular and proprioceptive. You use these to
help you get out of bed each morning; most of us will roll to our side, push
up with our hands to get into a sitting position, then rise to stand from
there. - There is a lot of rotation needed to get us into the upright position. When
you think of righting reactions, think of rotation.
Describe equilibrium reactions
- Automatic responses to changes in posture and movement aimed
to preserve or restore balance. - These reactions are seen in the trunk, head, and extremities as the
center of gravity (COG) is displaced over the base of support (i.e. a
far reach). - Reaction depends on the speed and direction of the displacement;
generally, the head and trunk curve against gravity and the arms
and legs attempt to equalize the body over the base of support through abduction, flexion or extension, and finally, if the COG is displaced to the point of fall, the trunk will rotate. - These reactions occur in a sequence as the child develops and can
be elicited by displacement of the body while in prone, supine, sitting, all 4’s, kneeling, or standing. - In equilibrium reactions, maturation of one reaction is only completed after the child has moved on to next milestone–i.e. a child does not have complete balance or righting in sitting until after they have begun standing
What are the types of equilibrium reactions?
1) protective reactions
2) tilting reactions
3) postural fixation reactions
These are automatic reactions which the body uses to maintain its center of gravity over its base of support, whether balance is displaced by volitional movement or an external force.
Describe protective extension reactions (UE)
- Forward–When the body is displaced forward, the shoulders flex, the arms extend and abduct, the hands open; arms support on hands with contact on floor or object; seen beginning at 6-7 mos. of age.
- Sideways–When the body is displaced sideways, the arm in the direction of force abducts and extends at elbow and hand, support on hand with contact with floor or object; emerge at 7 mos. of age.
- Backward–When the body is displaced backward, the shoulders and arms extend, the hands open, and there is support on hands with contact on floor or object ; emerge at 9-10 mos. of age.
- Downward–(also called UE parachute reaction); When, from a vertical suspended position, the body is displaced down toward the supporting surface, the arms extend and abduct and the hands open. These are seen at the same age as the ‘forward’ ones.
Describe protective extension reactions (LE)
- Staggering reactions–When the body is displaced forward, sideways and backward, the legs and feet will flex, extend, abduct and adduct to maintain the base of support under the center of gravity; seen beginning at 15-18 mos. of age (after ~3 months of walking experience.)
- Downward–(also called LE parachute reaction); When, from a vertical suspended position, the body is displaced downward vertically, the legs extend, abduct and externally rotate, the feet dorsiflex, and support is taken on legs with contact; emerge at 4 mos. of age.
*Remember, these are reactions, so they are seen as the child matures and remain present. We will be able to elicit these in each other in lab.
Describe tilting reactions
- These are like equilibrium reactions, except that the base of support is displaced under the center of gravity (i.e. on a moveable surface).
- Like equilibrium reactions, the type and extent of tilting reactions depends on the speed and direction of displacement.
- These reactions look similar to the equilibrium reactions, and also occur in developmental sequence.
- In response to a mild perturbation, we will see a concave curve of the spine to upper side. With more rapid or pronounced tilting, will also see extension of extremities on upper side.
- Finally with very rapid or pronounced tilt, we will see extension
of extremities on both sides with rotation toward the tilt. - These emerge in prone (5 mos.), supine (7-8 mos.), sitting (7-8 mos.), all 4’s (9-12 mos.), then standing (12-21 mos.).
Describe postural fixation (postural adjustments)
- The purpose of these is to brace and contract appropriate groups of
muscles to provide support and react against rotational or horizontal
forces (i.e. how you prepare when walking in mall and see a kid about
to run into you, or how you react after being bumped by said kid). - These reactions occur in developmental sequence as the child
develops against gravity and develop in a cephalocaudal direction within each developmental position. - Reactions first develop in an anterior-posterior direction (Sagittal plane), then laterally, and finally in a diagonal pattern.
- When seen prior to the disturbance, they are referred to as anticipatory, following the disturbance they are referred to as reactive.
What do these reflexes/reactions provide?
- normal postural tone of moderate intensity, high enough to resist gravity, but low enough to permit movement
- normal reciprocal interaction of muscles for
* a. synergic fixation proximally to allow for selective mobility of distal segments (“skill”)
* b. automatic adaptation of muscles to changes of posture during movement
* c. graded control of agonists and antagonists integrated with that of synergists for timing and direction of movement (i.e. in protective extension of UE’s) - automatic posture and movement which is the background for voluntary,
functional activities
Can reflexes/ reactions facilitate a large variety of active movement patterns and increase the client’s normal movement pattern?
Yes, normal postural reactions can be facilitated by carefully using appropriate exteroceptive or proprioceptive stimuli.
They may also provide a way to control the abnormal tone and patterns of movement seen in clients with CNS dysfunction (i.e. cerebral palsy).
What is the purpose and origin/integration of Labyrinthine Head Righting?
Purpose: corrects orientation of the body when it is taken out of its normal upright position
Origin: 0-2 mo
Integration: persists throughout life
What is the stimulus and response of Labyrinthine Head Righting?
Stimulus: (vestibular-otolith, proprioceptors-neck) subject blindfolded and held in vertical suspension or sitting. Tilt anteriorly, posteriorly, and to each side
Response: head orients to vertical position (face vertical, mouth horizontal). If tilted too far, will align with trunk
What is the purpose and origin/integration of Optical Righting?
Purpose: helps the head orient itself using visual inputs
Origin: 0-2 mo
Integration: persists throughout life
What is the stimulus and response of Optical Righting?
Stimulus: (vision) like “optical righting” but subject is not blind. Observation of movement
Response: rights head and body in relationship to environment
What is the purpose and origin/integration of Landau?
Purpose: Helps develop the motor control of the back (posterior) body and relationship of horizontal and vertical perspectives of the body
Origin: 3-4 mo
Integration: 12-24 mo
What is the stimulus and response of Landau?
Stimulus: (Labyrinths, proprioceptors of neck and trunk) Horizontal suspension, supported only at abdomen or over lap
Response: Head raises, evoking a chain extension response to include shoulders, back hips, knees
What is the purpose and origin/integration of Neonatal Neck on Body Righting?
Purpose: to keep head in normal upright position or to support the head to come in an upright position
Origin: 34 weeks GA
Integration: 4-5 mo
What is the stimulus and response of Neonatal Neck on Body Righting?
Stimulus: (Propriocepive cervical spine) Turn subject’s head to one side
Response: body will follow in log-roll fashion
What is the purpose and origin/integration of Neonatal Body on Body Righting?
Purpose: to keep head in normal upright position or to support the head to come in an upright position
Origin: 34 weeks GA
Integration: 4-5 mo
What is the stimulus and response of Neonatal Body on Body Righting?
Stimulus: flex knee and rotate pelvis to one side
Response: head and upper trunk will follow in log-roll fashion
What is the purpose and origin/integration of Body Righting Acting on the Head?
Purpose: helps keep the body oriented with respect to the ground or surface regardless of the position of the head
Origin: 0-2 mo
Integration: 5 years
