By the time children enter primary school, they have developed several important fine motor skills, such the ability to tie a shoe or button a coat. However, as kids enter kindergarten, they are still learning new ones. And, while most people think of middle childhood as a time of developing mental capacity and adolescence as a time of physical change, middle childhood does witness some important milestones of motor development.
By the start of adolescence, the average child will have gone from 45 inches tall and 45 pounds to 5 feet and 90 pounds. As always, environmental and genetic factors influence a child's growth during primary school. For instance, the bodies of children stop growing during even mild illness. Poor children who lack access to health care and proper nutrition do not experience the "catch-up" growth needed after illness that children with better resources do. As a result, they end up with stunted height. Quantity and quality of food during these years, in addition to genetic inheritance, also play a role in weight gain.
During primary school, balance and agility improve, allowing children to participate in more complex physical activities. They can learn to skate, ride bikes, sail boats, dance, swim and climb trees. Primary school kids also develop the ability to hop on one foot, a skill not seen in preschool children.
This ability to stand on one foot allows primary school children to kick a ball. A young child who is trying to kick will just shove her whole leg forward. As she improves, she will add more complex steps including stepping forward, cocking the leg, and taking a small swing. At the end of middle childhood, she will involve her whole body, including arms and torso, in the kick. Older children can also throw balls farther, with more efficiency, and better catch them.
These specific skills, such as kicking and throwing, do not develop in 10 percent of 9- to 10-year-olds. This indicates that practice is needed for these gross motor skills to improve.Throughout the primary school years, until puberty, boys have a slightly greater muscle mass than girls. However, the difference is so tiny during this period of development that it doesn't account for the fact that boys are better at jumping, running, throwing, kicking, dribbling and catching while girls are better at agility and fine motor skills such as drawing or writing. Indeed, during childhood, cultural expectation determines the practice that each gender receives, and therefore, its ability in those skills. Practice or lack thereof, on the other hand, is the primary reason for the gender gap in motor development.
Recent research has attempted to uncover what is causing this difference in practice between boys and girls when it comes to gross motor skills. Developmental psychologists have demonstrated that peer popularity among boys relates more to athletic abilities and gross motor skills, which motivates them to practice more. Furthermore, while the participation of girls in sports has gone up dramatically in recent years, a 2002 study by T.S. Horn, a professor at the University of Illinois, showed that boys still receive more encouragement, coaching and reward in areas of physical development.