09/02/2024
Fourth Month Motor Development
baby uses bilateral symmetrical control of the flexor and the extensor ms.
baby's neck flexor ms balance neck extensor ms and enable to maintain and control of the head in midline in prone and supine and sitting.
babies can easily move the head in and out the midline.
prone baby move into total extension pattern, which demonstrates the baby's increased extensor ms tone and control.
extension is reinforced by bilateral scapular adduction. Scapular adduction is used to reinforce trunk extension. It is also seen in sitting, standing, and walking.
pectoral ms adduct the arms in line with the trunk by this shoulder adduction helps to facilitate abdominal ms contractions and head flexion this enables baby to tuck the chin and elongate the neck.
can prone on the forearm with symmetrical weight bearing.
baby can play in prone with pelvic tilts by actively alternating ant and post pelvic tilts.
pelvic tilting accompanied by lumber extension, hip flexion, knee flexion, and ankle dosriflexion.
# Post pelvic tilting are accompanied by hip extension, knee extension, and ankle planter flexion.
frog-legged position of hip flexion, abduction, and external rotation that occurs in the four-month-old is less marked than that of the three-month-old.
four months, the hip adductors bring the legs closer together and elongate the hip abductors and hip flexors.
# While in forearm weight bearing, the baby may
accidentally roll to his side.
is usually initiated by strong head extension and or collapse of control of the muscles of one shoulder when the weight shifts to that side.
forearm weight shifting is usually seen at five month of age.
supine, the four-month-old baby demonstrates increased antigravity flexor muscle control.
baby lifts the head, arms, and legs to reach the hands to the knees.
hands-to-knees position enables the baby to explore the body and increase body awareness. Vision usually leads the reaching.
the baby brings his hands to his knees, he
frequently rolls over to his side.
is usually initiated with head rotation. When the head turns, the body follows as a unit.
is usually maintained in side-lying. Once in side-lying, visual and vestibular feedback provide the stimulus for lateral head righting.
pulled to sit from supine, the four-month-old initiates the lift.
lifts the head symmetrically, lifts the
pelvis with the abdominals, flexes the elbows, and flexes the hips and knees.
shoulders elevate to stabilize the head once the movement is initiated.
in the sitting position, the baby leans forward at his hips, followed by trunk extension.
baby still lacks trunk and hip control and must be supported in sitting.
placed in standing, the baby takes weight on his feet. He can be supported at the hands instead of the trunk, which indicates increased hip and trunk control.