Human Development and Aging
What the exam expects
You must know typical motor, cognitive, and psychosocial milestones across the lifespan and how they alter examination findings and prognosis. Key concepts: gross/fine motor sequencing, primitive reflex emergence and integration, postural control development, adolescent growth spurts, and age-related declines in strength, balance, vision, hearing, and reaction time. Understand that aging is heterogeneous-chronologic age is a poor proxy for physiologic reserve-and that frailty, sarcopenia, and polypharmacy modify presentation.
Traps
Questions often present a normal variant as pathology (e.g., asymmetric tonic neck reflex in a young infant, genu varum in toddlers, widening gait in older adults). Another trap is assuming developmental delay from a single missed milestone without considering prematurity-adjusted age. Watch for questions conflating regression (loss of skills, a red flag) with plateau. Also beware attributing decline to "normal aging" when it exceeds expected rates.
Rule of thumb
Adjust developmental expectations for prematurity until roughly 2 years corrected age, and treat any loss of previously acquired skills as pathologic until proven otherwise.
Worked example
A 9-month-old born at 28 weeks (3 months early) is not yet sitting independently. Corrected age is 6 months, at which independent sitting is not yet required-so this is not clearly delayed. Document corrected age and monitor rather than labeling delay.