Final answer:
Infants may struggle with upright posture due to muscle weakness, lack of coordination, and developmental delays. These factors affect motor skills that are crucial for maintaining balance and achieving milestones like sitting and standing. Early intervention can address these issues.
Step-by-step explanation:
Infants may have difficulty with upright posture due to 4) All of the above: muscle weakness, lack of coordination, and developmental delays.
Infants develop motor skills in a sequential manner, starting from reflexive actions such as sucking to complex movements like walking. Achieving upright posture, including sitting and standing, requires these developing motor skills, supported by muscle strength, coordination, and proper developmental timing. Developmental milestones provide a benchmark for typical age ranges during which a child should gain these abilities, like sitting by 7 months. Delays in milestones might indicate an underlying issue. Infants with muscle weakness might struggle to support their weight or maintain balance.
Coordination is vital for smooth transitions between postures, keeping balance, and motor planning. Any delay in coordination can disrupt the ability to achieve and maintain an upright posture. Developmental delays can be attributed to various factors, including genetic conditions, traumatic birth, undernutrition, or low birthweight, which can interfere with the normal maturation process necessary for posture control. Assessment by a pediatrician and early intervention can identify and mitigate the impact of these challenges on an infant's motor development.