Pediatric foundations
Developmental milestones
The following developmental milestones are organized by the age at which they typically occur:
2 months
- Holds head up in prone to 45 degrees
- Does not accept weight on the lower extremities
- No head control during support sitting
4 months
- Rolls prone to side, supine to side
- Head control demonstrated in supported sitting
- Ulnar-palmar grasp
- No head lag when pulling up to sit
6 months
- Rolls supine to prone
- Independent sitting
- Prone on extended arms and weight shifting with extended arms
8-9 months
- Creeping
- Pull to stand via kneeling with furniture
- Can stand independently for 1-2 seconds
- Able to transfer objects between hands
- Independent with side-sitting
10-15 months
- Independently walking
- Creeps up/down steps
- Transfers floor to standing
20 months
- Ascends steps with step-to-step pattern while holding unilateral rail or hand
- Uncoordinated running pattern
- Able to jump from a 2-inch step independently
24 months
- Ascends steps with step-to-step pattern independently without holding unilateral rail or hand
- Uncoordinated running at increased speed
Primitive reflexes
The following are the primitive reflexes, along with the age at which each typically appears and integrates:
Rooting
- Definition: stroking the cheek to allow for locating the bottle nipple or breast for consuming milk
- Age: appears at birth, integrates by 3-4 months
Moro
- Stimulus: sudden loss of head support, such as the head dropping backward
- Response: arms abduct and extend with fingers fanned, then adduct and flex toward midline in an “embrace”; the infant often cries
- A loud noise triggers a separate startle reflex, not the Moro reflex
- Age: appears at birth, integrates by 4-6 months
Palmar grasp
- Definition: grasping of an object when placed in the palm
- Age: appears at birth, integrates by 5-6 months
Asymmetrical tonic neck reflex
- Stimulus: the infant’s head is turned to one side
- Response: the face-side arm/leg extend while the skull-side arm/leg flex; aids in developing muscle tone, hand-eye coordination, and motor skills
- Age: appears at birth, integrates by 6 months
Spinal galant
- Definition: stroking laterally to the spinal column causes lateral flexing to the ipsilateral side
- Age: appears at birth, integrates by 3-9 months
Tonic labyrinthine reflex
- Stimulus: neck flexion or neck extension
- Response: flexion causes the arms/legs to flex, extension causes the arms/legs to extend; aids the infant in learning to control the head and neck
- Age: appears in utero, integrates by 3.5 years
Symmetrical tonic neck reflex
- Stimulus: neck flexion or neck extension
- Response: flexion causes the arms to flex and the legs to extend; extension causes the arms to extend and the legs to flex; aids the infant in learning to control the upper and lower body independently
- Age: appears at 6-9 months, integrates by 9-11 months
Landau
- Stimulus: infant held in prone horizontal suspension (held horizontally in the air)
- Response: the infant lifts the head and extends the trunk and legs, forming an arch in the back; aids in motor control and coordination
- Age: appears at 4-5 months, integrates by 12 months
Babinski
- Definition: involuntary movement that occurs when the foot is stroked
- The lateral edge of the foot is stroked, causing extension and fanning of the toes
- Age: appears at birth, integrates by 2 years
Flexor withdrawal and crossed extension
- Flexor withdrawal
- Definition: protective reflex that occurs when a sharp pressure is applied to the sole or the palm, causing withdrawal (flexion) of that same stimulated extremity
- Age: appears at birth, integrates by 1-2 months
- Crossed extension
- Definition: protective reflex tested with one leg held in extension: a noxious stimulus to the sole of that leg causes the opposite (free) leg to flex, adduct, and then extend - the response is in the opposite limb, unlike flexor withdrawal, where the stimulated limb itself withdraws
- Age: appears at birth, integrates by 1-2 months
Primary standing
- Definition: an infant, when placed in a standing position, will support some weight and extend lower extremities
- Age: appears at birth, integrates by 2 months
Primary walking
- Definition: when the infant is held upright with the soles of the feet touching a flat surface, a slight forward tilt of the trunk elicits reciprocal (alternating) stepping movements
- Age: appears at birth, integrates by 2 months
Plantar grasp
- Definition: pressure on the sole or lower foot causes the toes to curl
- Age: appears at birth, integrates by 9 months
ATNR, STNR, and TLR are easy to mix up because they all key off head or neck position but produce opposite limb responses. The table below lines them up side by side for quick reference:
| Reflex | Stimulus | Limb response |
|---|---|---|
| Asymmetrical tonic neck reflex (ATNR) | Head is turned to one side | Face-side arm/leg extend; skull-side arm/leg flex |
| Symmetrical tonic neck reflex (STNR) | Neck flexion or neck extension | Flexion: arms flex, legs extend. Extension: arms extend, legs flex |
| Tonic labyrinthine reflex (TLR) | Neck flexion or neck extension | Flexion: arms/legs flex. Extension: arms/legs extend |
Example: recognizing a persistent reflex
During a treatment session, a PTA notices that a 10-month-old still shows a strong ATNR response - turning the head causes the face-side arm/leg to extend and the skull-side arm/leg to flex - well past the reflex’s expected integration age of 6 months.
Answer: As a PTA, you document the finding within the plan of care the supervising PT has established and report it to the PT rather than diagnosing the cause or independently changing the plan of care; the PT determines whether further evaluation or a change to the plan of care is warranted.
Postural reactions and movement analysis
Righting reactions
- Head righting: tilting the body causes the head to right itself to vertical, with the face vertical and the mouth horizontal
- Body righting: rotating the head or trunk causes the rest of the body to rotate and realign with it
Protective (parachute) reactions
- Forward: tilting the infant toward a surface causes the arms to extend forward to catch the fall (emerges around 6-7 months)
- Sideways: tilting the infant to the side causes the arm on that side to extend to catch the fall (emerges around 7-8 months)
- Backward: tilting the infant backward causes the arms to extend behind the body to catch the fall (emerges around 9-10 months)
Equilibrium reactions
- Prone/supine: tilting the support surface causes trunk curvature and extension of the limbs on the raised side (emerges around 6 months)
- Sitting: tilting while seated causes trunk curvature and limb extension on the raised side to maintain balance (emerges around 7-8 months)
- Standing: tilting while standing causes trunk and limb adjustments to maintain balance (emerges around 12-21 months)
When you observe a child’s movement, you’re also watching for atypical patterns - toe walking, scissoring (the legs crossing from hip adductor overactivity), or a primitive reflex still dominating movement past its expected integration age. As a PTA, you document these findings and report them to the supervising PT, the same way you would an out-of-range milestone or reflex finding.
Newborn considerations
Full term is about 40 weeks (37-42 weeks); infants born before 37 weeks are preterm and have an increased risk of developmental delay and medical complications.
Infants are assessed at 1 minute and 5 minutes after birth (and every 5 minutes thereafter, up to 20 minutes, if the 5-minute score is below 7) via the APGAR scale. The APGAR scale assesses appearance (color), pulse, grimace (reflex irritability), activity, and respirations. Each is scored with a 0, 1, or 2, with the goal of the score being between 7-10. At every assessment, the expectation is that the score will go up. Scores below 7 indicate the newborn may need additional support or monitoring.
Examination of the newborn also includes assessment of the musculoskeletal system, range of motion, posture, primitive reflexes as appropriate, and tone. Any abnormalities noted will be the rationale for performing specific outcome measures for assessment.
Congenital neurological and genetic conditions noted at birth include the following:
- Anencephaly is a neural tube defect in which a baby is born without parts of the brain and skull; it is fatal, and almost all affected babies die shortly after birth.
- In Chiari type I the lower part of the cerebellum extends into the upper spinal canal; Chiari type II displaces the brainstem and cerebellum into the spinal canal and occurs almost exclusively in patients with myelomeningocele.
- Prader-Willi syndrome and Angelman syndrome involve chromosome 15, not an extra chromosome 21 as in Down syndrome: Prader-Willi arises from loss of the paternal 15q11-q13 genes (a paternal deletion, or two maternal copies of chromosome 15), and Angelman arises from loss of the maternal copy (a maternal deletion or UBE3A loss, or two paternal copies).
Outcome measures
Alberta infant motor scale (AIMS)
- Definition: gross motor skills assessment tool used to evaluate weight-bearing, posture, and antigravity movements in infants
- Age of use: 0-18 months
Peabody developmental motor scales (PDMS-2)
- Definition: assesses gross and fine motor development, including reflexes and automatic (postural) reactions; used primarily with children who have developmental delay
- More sensitive to change than the Bayley scales of infant development
- Age of use: 0-5 years (birth to 71 months)
Gross motor function measure (GMFM-88)
- Definition: measures gross motor function in the cerebral palsy population
- Focuses on voluntary movement in five dimensions - lying and rolling, sitting, crawling and kneeling, standing, and walking, running, and jumping
- Age of use: 5 months to 16 years
Bruininks-Oseretsky test of motor proficiency (BOT-2)
- Definition: developed to measure gross and fine motor skills for individuals with developmental delay
- Age of use: 4-21 years
Bayley scales of infant development
- Definition: developed to measure motor and mental scales for children with developmental delay
- Assesses 5 domains: cognitive, language, motor, social-emotional, adaptive
- Age of use: birth to 42 months
Functional independence measure for children (WeeFIM)
- Definition: assesses function in self-care, mobility, locomotion, and social cognition in children following an acute injury, such as spinal cord injury, traumatic brain injury, or multiple fractures
- Age of use: 6 months to 7 years