West Coast Sports Medicine Foundation
Director, Orthopedic Foot & Ankle
Young athletes are either still growing or have only recently reached skeletal maturation. On average, females obtain their full height at age fourteen, and males at age sixteen. However, there is a wide range of skeletal maturation rates, and variations of a year or two on either side of the averages is not unusual.
The so-called adolescent growth spurt typically begins about two years before skeletal maturity and peaks during the following twelve months, and then gradually slows to a stop during the twelve months prior to maturity (of the skeleton, not emotional or psychological maturity unfortunately).
Adolescence is the peak of growth in a kid, although this is not an exact science. Some kids mature faster and earlier than others. Younger children grow more slowly, as a general rule, and play with less intensity (although this seems to be changing). For this reason, most kids’ injuries occur during adolescence.
Growth Plates discussion is key!
The growth plate in a bone is an important part of this discussion. Let me define what a growth plate is. A growth plate is an area of growing tissues at the end of a bone—such as in the arm or leg—that is present in immature children and adolescents.
Growth in the long bones (thigh bone and shin, for example) occurs through the multiplication of specialized cartilage cells located in the growth plates (physis) of the long bones—the part of the bone that can grow. Many bones have growth plates at both ends.
During growth, these cartilage cells multiply and move away from their point of origin, toward the center of the bone. They are then gradually transformed from cartilage to bone, and the bone grows in length. In the last year of growth, the growth plates narrow as the rate of multiplication of the cartilage cells decreases.
Where Are Growth Plates Located?
As growth ends, the growth plate has narrowed to the point where the bone on either side fuses together and no more growth can occur. Growth plates are located in the knee, ankle, heel, and wrist.
The growth plate is a source of injury for many kids. Here’s why: The cartilage of the growth plate is weaker than the surrounding bone and can be fractured. Fractures to the growth plate are thought to be more common during periods of rapid growth.
The adolescent growth spurt is a common time for injury to the growth plate. And just for medical purposes, we call bone breaks fractures. A fractured bone is a broken bone. It’s the severity of the “break” that also can be measured.
An injury to the growth plate is a unique injury that only children can sustain. The growth plate can be injured with trauma or overuse. In boys, typically the growth plate is open (growing) until they are fifteen to eighteen years of age. The growth plate in girls is usually open until a year or so after she starts her periods (ages twelve to fifteen). Repetitive injuries to the growth plate are a type of stress fracture. Luckily most heal without any problem.
What Are The Most Common Growth Plate Injuries?
The most common growth plate injuries in youth sports are in the ankle and the wrist. Growth plate injuries around the ankle come as a result of a twisting injury and can produce significant swelling and severe pain with weight bearing. These injuries can be mistaken as “just a sprain.” The swelling and pain with weight bearing indicate that this is a more severe injury.
Growth plate injuries at the wrist usually result from an attempt to break a fall by putting the hand out. This injury will produce swelling, pain, and even deformity around the wrist. This injury can also be mistaken as a sprain. A persistent complaint of pain, especially associated with a limp (ankle), requires immediate medical evaluation.
A special type of growth plate, the apophysis, is present at the site where many large muscles attach to bone. These growth plates have a role in shaping bones to withstand the large stress that major muscles place on them. An example of an apophysis is the back of the heel where the Achilles tendon inserts, the front of the knee at the site of attachment of the patella tendon (to the kneecap), and the medial epicondyle on the inner side of the elbow (Little League elbow) where the wrist flexors originate. These growth areas are commonly injured from overuse (too many pitches or too high a pitch count, multiple overhead spikes, or too many overhead hits and serves, depending on the sport).
Little League elbow
Many of these overuse injuries can be prevented with proper warmups and stretching. Some of these injuries require a change in mechanics, such as with Little League elbow. With Little League elbow there needs to be a change in throwing mechanics, decreased use of the curve ball (among pitchers), change in position (pitcher to first base, for example), or no throwing.
In general, apophyseal injuries get better with rest and will surely get worse if the painful activity is continued (or not modified). Playing through the pain will, in general, only lead to more severe pain and poor performance. Playing through pain is not character building.
Kids Bounce Back Fast
Even though immature bones and muscles can be more at risk for injury, on a brighter note, kids recover quicker than adults.
Sometimes maturation brings a temporary decrease in balance and coordination for young athletes. During puberty, limb length, mass, and overall size all change with age. The limb length can increase 1.4 times from ages six to fourteen. The mass of the arm and leg may triple. So during growth, a mismatch in length and muscle size can lead to imbalance.
Muscles need to get stronger to move the bigger limb, and sometimes muscle strength and bone growth do not match. This creates increased strain on the tendons, ligaments, muscles, and growth plates. High-intensity sports such as football, basketball, and lacrosse will put all these body parts at even more risk for injury.
As kids grow bigger and stronger, the risk for injury increases, largely because of the amount of force involved. For example, a collision between two eight-year-old Pee Wee football players who weigh 65 or 70 pounds each does not cause as much damage as that produced by two sixteen-year-old high school football players who each may weigh over 200 pounds.
However, kids mature at different rates. There is often a big difference in height and weight among kids of the same age. Sometimes there is a hodge podge of players on the field. Rough play can cause serious injury to the smaller, less mature players.
Genetics is a big factor in how big and how fast a kid will grow. There is no predictable scientific formula to determine how big a child will eventually be, however. It helps a lot if the parents are big and tall though.