Infant Motor Development: 0-12 Months

• Students will be able to describe the typical sequence of gross motor development from birth to 12 months.
• Students will be able to identify the expected age ranges for key gross motor skills, such as head control, rolling, sitting, crawling, pulling to stand, cruising, and walking.
• Students will be able to explain the influence of postural control, strength, sensory integration, and movement patterns on the acquisition of gross motor milestones.
• Students will be able to understand how to apply knowledge of motor development to clinical decision-making when evaluating and treating infants in a physical therapy setting.

Birth to One Month

• This is a period dominated by physiological flexion and limited range of motion.
• The active movements are limited by the available range of motion.
• The movements are random and total in pattern.

Birth to One Month, Gross Motor (Prone)

• Physiologic Flexion dominates.
• The baby keeps their head turned to the side.
• Head preference is typical.
• Head and neck extension begin to emerge (antigravity activation).
• The baby brings their mouth to their hand.
• The upper extremities are adducted/flexed with shoulders elevated to the ears
• The lower extremities are flexed with an elevated pelvis and with weight shifted to face.

Birth to One Month, Gross Motor (Supine)

• Head is turned to one side.
• The baby uses gross swiping motions of Upper extremities.
• Kicking patterns of lower extremities range from rhythmical and reciprocal to random and variable.

Birth to One Month, Gross Motor (Sitting)

• Requires Full Support to sit.
• The baby has a fully rounded back and flexed neck.
• They have poor active control of the head (head bobbing).
• Pull-to-sit: Marked Head Lag, minimal UE traction noted.

Birth to One Month, Gross Motor (Upright)

• Requires full support at upper trunk.
• Head bob in and out of vertical.
• Visually tracks horizontal and vertical in very small ranges.
• Positive support reaction – accepts weight briefly on lower extremities.
• Automatic stepping seen.

Birth to One Month - Reflexes/Reactions

• Sucking appears at 7 months.
• Rooting appears at 9 months.
• Palmar Grasp appears at 4 months.
• Plantar Grasp appears at 12 months.
• Moro appears at 6 months.
• ATNR appears at 5 months.
• STNR appears at 5 months.
• Crossed Extension appears at 2 months.
• Neck Righting appears at 4 months.
• Positive Support Reaction appears at 2 months.
• Primary Standing appears at 3 months.
• Primary Walking appears at 5 months.
• Placing Rxn Foot appears at 4 months.
• Flexor Withdrawal appears at 2 months.
• Survival Instinct appears at 12 months.
• Tonic Labrynthine Prone and Supine appears at 4 months.

Two Months

• This is a period dominated by general hypotonia.
• Overall decreased flexion.
• Increased extension.
• Asymmetry.
• Baby appears to have less control of the body.

Two Months Gross Motor (Prone)

• Upper Extremities have increased external rotation and abduction with elbows remaining behind the shoulders.
• Hips are more extended with the pelvis moving closer to the surface.
• Weight shifts caudally to shoulders.
• Lifts head to 45 degrees asymmetrically by the end of this month.
• Head Lifting and activation may be motivated more by visual righting.

Two Months, Gross Motor (Supine)

• Upper Extremities are held in increased external rotation and abduction with gravity assistance.
• Lower extremities have increased extension as physiologic flexion reduces.
• Head rarely held in midline due to the influence of ATNR.

Two Months Gross Motor (Supported Sitting)

• Continued head lag in pull to sit means the baby now begins to initiate neck flexion.
• The baby can hold their head erect briefly, however, it continues to bob.

Two Months, Gross Motor (Upright)

• The baby is unable to hold weight on legs.
• They have less control than ay one month.
• Astasia-Abasia exists
• Astasia - disorientation in standing
• Abasia - lack of stepping

Two Months -Reflexes/Reactions

• Labyrinthine Righting Reaction appears at 12 months.
• To test Labyrinthine Righting Reaction, you must hold the infant vertically at chest, and tilt child anterior, posterior, and laterally where the head orients to vertical position and steady.
• Body Righting on Body appears at 12 months.
• Body Righting on Body requires flexing one lower extremity rotating across the pelvis, where the Infant will turn body segmentally.
• Body Righting on Head appears at 7 months.

Three Months

• Beginning of symmetry.
• Bilateral control of neck musculature.
• Antigravity flexor control emerges.
• Midline orientation of head emerges.
• Increased alertness/awareness of environment.

Three Months Gross Motor (Supine)

• Able to bring Upper Extremities to midline on the chest.
• Holds Lower Extremities with soles of feet together, also known as frog Leg.

Three Months Gross Motor (Prone)

• Pushes head up to 90 degrees and turns freely initiating weight shift.
• Ability to turn head on forearms allows for the initiation of a subtle weight shift.
• Upper extremities have increased horizontal ab/adduction which supports forearm weight bearing.
• Lower extremities are positioned with pelvis to surface and wide base, also known as frog leg.

Three Months Gross Motor (Supported Sitting)

• Increased flexion control in pull to sit.
• Head held up, trunk leans forward with scapular retraction present.

Four Months

• Where the fun begins.
• Strong Symmetry.
• Bilateral control of extensor and flexor muscles leads to increased control.
• Head control much improved.
• Emergence of controlled purposeful movement.

Four Months Gross Motor (Prone)

• Increasing antigravity control emerges.
• Increased extension through back and neck.
• They Can hold head in midline with neck elongation emerging reducing neck hyperextension.
• Forearm weight bearing pushing up on extended arms, and they bears weight on palms.
• Increased lumbar extension and anterior pelvic tilt with legs more in line with trunk.
• Weight Bearing more into the pelvis.
• Swimming movements emerge.

Four Months Gross Motor (Supine)

• Increased balance of flexors/extensors.
• Increasing midline position of hands.
• Emerging ability to reach for knees.
• Active hip and knee flexion.
• Emerging abdominal control, decreased hip abduction.

Four Months Gross Motor (Sitting)

• Baby pulls to sit with increased symmetry.
• Increased abdominal and lower extremity activity.
• More straightening of the back, arms forward in ring sitting.

Five Months

• Begin to see equilibrium reactions.
• Bear weight on extended arms.
• Weight shifts on propped forearms
• Baby can pivot prone.
• Baby rolls to supine.

Five Months, Gross Motor (Supine)

• Upper Extremities held in increased external rotation and abduction with gravity assistance.
• Baby has increased weight shifting.
• Increased weight shifting leads to increased proprioceptive feedback.

Five Months, Gross Motor (Sitting)

• The baby pulls to sit with active abdominal and arm assisting with pulling.
• Increased active back extension, forward leaning at hips versus back in ring sit.
• Abducted hips provide stability.
• May sit alone for brief periods.

Five Months, Gross Motor (Upright)

• Takes almost full weight in hand held standing.

Five Months - Reflexes/Reactions

• The parachute reflex occurs at 12 months where the baby is Held above surface in ventral suspension and the Infant extends arms to protect fall
• Landau reflex occurs at 12 months and after, where the baby is supported horizontally in air in prone position, and their Head extends back, hip extend in sequence.

Six Months - Gross Motor (Prone)

• The baby Shifts weight on extended arms.
• Unilateral reaching is seen in close to ground prone postures.

Six Months, Gross Motor (Supine)

• They Lift head from the surface independently.
• They Roll supine to prone with dissociation of lower extremities.

Six Months, Gross Motor (Sitting)

• The baby Pulls to sit, initiating the action with arms while tucking head and flexing legs
• Baby's arms are free for play and protective extension
• They'll have good sagittal plane trunk control (anteriorly).
• Poor transverse plane trunk control

Six Months, Gross Motor (Upright)

• Takes full weight with assist at hands and bounces.

Seven Months, Gross Motor (Prone)

• Attains quadruped, abdomen off floor, initiates rocking (increase proprioception)
• The baby does brief crawling (commando)

Seven Months, Gross Motor (Supine)

• The baby has spends very little time in supine by this age
• They are More interested in the other postures and readying self for increased mobility

Seven Months, Gross Motor (Sitting)

• The baby Can assume sitting from the quadruped position
• Trunk rotation is present in sitting position
• The baby Transitions from sitting to prone

Seven Months, Gross Motor (Upright)

• Baby Pulls themselves to stand against stable surfaces
• Baby Falls back into sitting with no controlled lowering ability

Eight Months, Gross Motor (Prone)

• Creeps on hands and knees, also known as all fours crawling
• May crawl backwards at first

Eight Months, Gross Motor (Sitting)

• Less "fixing" with the lower extremities

Eight Months, Gross Motor (Upright)

• Baby pulls to stand thru kneel or 1½ kneel
• Cruises on support surface
• Stands with one hand held
• Stepping gait with both hands held

Nine Months, Gross Motor (Sitting)

• Sitting is the most functional and versatile position at this stage
• Protective Extension Backwards emerges

Nine Months, Gross Motor(Upright)

• Baby Can semi turn in standing
• They do Two hand held walking with decreased base of support

Ten Months, Gross Motor (Sitting)

• Baby Begins to use upper extremities for more intricate fine motor activities
• This Results in increased stabilizing ("fixing") of the lower extremities

Ten Months, Gross Motor (Upright)

• The baby Can lower themselves from standing to sit
• In two hand held walking, they start to develop pelvic rotation and lower extremity stride

Eleven Months, Gross Motor (Sitting)

• Baby shows Varied lower extremity positions
• They have Controlled trunk rotation
• They use 1½ kneel and kneel more

Eleven Months, Gross Motor (Standing)

• Baby transitions stand to squat while holding on
• stands alone with wide base of support and lower extremity abduction
• They show Refined cruising and reaching away from surface

Twelve Months, Gross Motor

• Baby Can stand from the floor through quadruped without using hands at supporting surface
• Able to weight shift and lift one leg from the surface
• Baby May attempt ambulation with high guard upper extremities and wide base of support in lower extremities.
• May be able to move in and out of squat