Physical Development of School Age Children

Most parents believe that their youngster's childhood passes much too quickly. Only yesterday, it seemed, you sang lulla­bies over your child's crib, or watched her crawl for the first time or take her first steps. Now she is bigger, more coordinated, more independent—and moving toward the much more dramatic changes of puberty that lie ahead.

The present changes tend to be more gradual and steady, all part of the evolution toward adulthood.

Most children have a slimmer appearance during middle child­hood than they did during the preschool years, due to shifts in the accumulation and location of body fat. As a youngster's entire body size increases, the amount of body fat stays relatively stable, giving her a thinner look. Also, during this stage of life a child's legs are longer in pro­portion to her body than they were before.

On average, the steady growth of middle childhood results in an increase in height of a little over 2 inches a year in both boys and girls. Weight gain aver­ages about 6.5 pounds a year. But these are only averages. A number of fac­tors, including how close the child is to puberty, will determine when and how much your child grows. In general, there tends to be a period of a slightly increased growth rate between ages 6 and 8 years, which may be accompanied by the appearance of a small amount of pubic hair.

Perhaps more than any other factor, your youngster's pattern of growth and ultimate height will be influenced by heredity. Your son, for example, may want to be one of the tallest boys in his class, and he may aspire to play pro­fessional basketball. However, if both you and your spouse have below-average stature, his height as an adult will be more like yours than like his favorite sports idols. While there are exceptions, tall parents usually have tall children, and short parents usually have short children. Those are the realities of genetics.

Even so, if your child seems unusually short or tall relative to her friends of the same age, talk with your pediatrician. The doctor may recommend X-rays to determine your child's bone growth. A true growth disorder can sometimes be treated by administering growth hormones; however, this therapy is re­served for youngsters, whose own glands cannot produce this hormone, thus interfering with normal growth. Physicians do not recommend this treatment for healthy boys and girls who may want (or whose parents may want them) to grow to be 6 feet tall instead of 5 feet 8.

Just as height can vary from youngster to youngster, so can the timing of a child's growth. Despite the averages mentioned above, many youngsters in middle childhood often experience clear growth spurts, followed by periods in which they grow very little. Some children grow as much as three times faster during a particular season of the year, compared with their "slow" seasons. These individual variations in timing—along with hereditary factors—are largely responsible for the wide variations in size among youngsters of the same age. Height differences among children in a typical elementary school classroom range from 4 to 5 inches.

A number of other factors—so-called environmental influences—can affect physical development as well. Nutrition is important to normal growth processes, and thus you should make an effort to ensure that your child con­sumes a well-balanced diet. Your youngster's need for calories rises during times of rapid growth, gradually increasing as she moves through middle childhood into puberty. However, if the calories consumed exceed those expended, your child may develop a weight problem.  Some parents worry that their child is not eating as much as she should. However, even with what seems to be relatively low food intake, children can grow at normal rates. Even if your school-age child is a picky eater, you do not usually have to worry that this frustrating behavior is impairing her growth. During these picky-eater phases, do not fall into the trap of feeling she will starve and thus give in to her desire for junk food. Her fluctuating eating habits may be due to normal slow-growth periods. Or she may simply have uniquely personal, unpredictable preferences or distastes for certain foods. In general, youngsters outgrow these food preferences without any harm to their physi­cal well-being. As long as your child is gaining weight appropriately (4 to 7 pounds per year) and is eating a healthy variety of foods, you can feel com­fortable that her nutritional needs are being met.

In our relatively affluent society severe malnutrition is uncommon. Never­theless, when a child's caloric intake is severely restricted—as in a disorder such as anorexia nervosa, or during a chronic illness—then her development and her overall health can be seriously harmed. Certainly if your child is los­ing weight, discuss this situation with your doctor. 

Your child also needs to exercise regularly to ensure normal physical devel­opment. Youngsters who spend their free time watching TV or engaging in other sedentary pursuits rather than playing outdoors may have impaired bone growth. Recent studies have shown that when physical activity is in­creased, bones are denser and stronger. Even so, there is no evidence that a very strenuous exercise program will help your child grow faster or bigger; running marathons, for example, will not stimulate her physical growth.

During middle childhood, you will probably notice a number of other prepu­bertal changes. Your child will become stronger as her muscle mass increases. Her motor skills—in both strength and coordination—will improve, too, re­flected in gradual improvements in tasks ranging from tying her shoes to throwing a baseball accurately. At five years old, a typical youngster can skip; walk on her tiptoes, and broad-jump. She is capable of lacing her own shoes, cutting and pasting, and drawing a person with a head, body, arms, and legs. By age six, a child can bounce a ball four to six times, skate, ride a bicycle, skip with both feet, and dress herself completely without help. While a seven-year-old may not be able to catch a fly ball, a ten-year-old probably can. While a nine-year-old can build a model or learn to sew, most six-year-olds cannot.

A school-age child's hair may become a little darker. The texture and ap­pearance of her skin will gradually change as well, becoming more like that of an adult.

Puberty often begins earlier than parents think. Breast budding in girls—their first sign of puberty—starts at age ten on average, with some girls starting as early as eight and others not starting until thirteen. The peak growth pe­riod (in height, weight, muscle mass, and the like) in girls occurs about one year after puberty has begun. Menstruation usually starts about two years af­ter the onset of puberty; on average, the first menses occurs just before girls turn thirteen.

Boys enter puberty about one year later than girls. The first sign is enlarge­ment of the testes and a thinning and reddening of the scrotum, which hap­pens at an average age of eleven but may occur anytime between nine to fourteen years. For boys, the peak growth period occurs about two years after the beginning of puberty. Puberty is made up of a clear sequence of stages, affecting the skeletal, muscular, reproductive, and nearly all other bodily sys­tems. Although boys and girls are generally of similar height during middle child­hood, that changes with the beginning of puberty. Particularly in junior high school, girls are often taller than their male classmates, but within a year or two, boys catch up and usually surpass their female classmates. About 25 per­cent of human growth in height occurs during puberty.

There are many opportunities during this time of life for you to talk to your child about what she's experiencing. Your child needs to understand the phys­ical changes that will occur in her body during puberty. You should emphasize that these changes are part of the natural process of growing into adulthood, stimulated by hormones (chemicals that are produced within the body).

Also, while fully respecting her desire for privacy, keep track of your child's bodily changes. As the age ranges above indicate, there are wide variations of "normal" in the time when puberty begins; remind your youngster that while she and her friends will grow at different rates, they will eventually catch up with one another.

On occasion, youngsters start puberty either very early or very late. There is no need to overreact to this phenomenon. Even so, girls should be checked by their physician if they begin pubertal changes before age eight, while boys should be evaluated if they enter puberty before age nine. Likewise, see a doc­tor if there are no pubertal changes in a girl by age thirteen or a boy by age fourteen.

Also, contact your physician if your child's pubertal development does not follow the typical pattern—for example, if your daughter begins menstruation before she experiences breast development. Your child can still continue seeing her pediatrician throughout these times of dramatic physical changes, and adolescence.