What are the differences in developmental norms related to mobility by age?
The infant’s mobility focus is on gross motor behavior, such as posture, head balance, grasping, sitting, creeping, and standing. Toddlers are more active, focusing on walking, running, kicking, and going up and down stairs. Preschoolers increase the skills and muscle strength by walking, running, and jumping. Children in middle childhood have improved posture, locomotion, and muscle efficiency of the extremities and trunk. Their muscle composition improves and their fat reserves decline. Adolescents develop the cardiac, respiratory, and metabolic functions to achieve physical conditioning. By middle age, there is a gradual decrease in muscle mass, strength, and agility. Older adults undergo bone resorption, muscle atrophy, and decreased joint flexibility.
