Growth Plates: A Parent's Guide to Your Child's Bone Development

If you’re a parent of a growing child or teenager, you’ve likely heard the term “growth plates” mentioned by doctors, coaches, or other parents. These crucial areas of developing bone tissue play a vital role in your child’s growth and development, and understanding them can help you make informed decisions about your child’s activities and medical care. This is particularly important if your child is experiencing growing pains or has been diagnosed with conditions like Osgood-Schlatter Disease or Sever’s Disease.

What Are Growth Plates?

Growth plates, technically known as epiphyseal plates, are specialised areas of cartilage tissue located near the ends of long bones throughout the body in children and adolescents. Think of them as nature’s building sites where new bone growth occurs throughout childhood and adolescence.

Unlike the hard, dense structure of mature bone, growth plates are made up of softer, more flexible cartilage cells. These cells actively divide and grow, gradually hardening into solid bone tissue in a process called ossification. This process is what allows bones to lengthen and widen as children grow.

What makes growth plates particularly important is their dual role: they’re not just responsible for bone growth, but they also serve as indicators of a child’s remaining growth potential. Each growth plate has its own timeline for closure, which typically corresponds with the end of that bone’s growth period.

How Growth Plates Work

Growth plates function as highly organised bone-building centres. Inside each growth plate, cartilage cells continuously divide and create new cells in a process that drives bone growth. This process is influenced by various factors including genetics, hormones (particularly growth hormone and testosterone), sleep, nutrition, and physical activity.

The growth process happens in stages, with different zones of the growth plate performing specific roles. New cartilage cells are created on one side of the growth plate, while older cells are transformed into solid bone on the other side. This continuous process allows bones to lengthen gradually and symmetrically, ensuring proper development and alignment.

What Age Do Growth Plates Close?

Growth plate closure follows a predictable pattern, though exact timing varies among individuals. Generally, girls’ growth plates begin closing earlier than boys’, which explains why girls typically start and stop their teenage growth spurts sooner:

• Girls usually complete their growth between ages 13–15
• Boys typically continue growing until ages 15–17

The closure process itself is gradual and follows a specific sequence throughout the body. Growth plates in the hands and feet are typically the first to close, while longer bones like the femur (thighbone) are usually the last to complete their growth. As children reach the end of puberty, their growth plates begin to harden and become solid bone through a process called epiphyseal fusion. Once a growth plate closes, that bone has reached its final length. This is why injuries to growth plates in younger children can potentially have more serious long-term effects than similar injuries in teenagers who are closer to completing their growth.

Medical professionals can monitor growth plate status through X-rays, where open growth plates appear as dark lines near the ends of bones. This information helps doctors track development and make important decisions about treating growth-related conditions or injuries.

Growth Plates and Common Conditions & Injuries of the Growth Plates

While growth plates are essential for normal development, their softer cartilage structure makes them vulnerable to both acute injuries and overuse conditions.

Direct trauma to a growth plate can be serious and requires immediate medical attention. However, more commonly, young athletes experience overuse conditions related to the sensitivity of the growth plates, combined with lower coordination, strength and flexibility during periods of rapid growth and high activity levels.

These overuse conditions, medically known as traction apophysitis, occur when repetitive stress affects the growth plate areas where tendons attach to bones. Two of the most common conditions are Osgood-Schlatter Disease (knees) and Sever’s Disease (heels).

Osgood-Schlatter Disease

Osgood-Schlatter Disease affects the growth plate at the top of the tibia (shinbone), just below the knee where the patellar tendon attaches. This condition typically occurs during periods of rapid growth, particularly in active adolescents aged 10–15 who participate in running and jumping sports. Osgood is a multi-factorial injury related to tightness in the quad muscles, hip instability and weakness, and poor motor patterning.

Sever’s Disease

Sever’s Disease (calcaneal apophysitis) affects the growth plate in the heel bone. It’s commonly seen at younger ages than Osgood in children aged 8–15 who are involved in sports that involve running and jumping. The condition occurs when the Achilles tendon and calves pull on the growth plate of the heel bone during periods of rapid growth. It is often exacerbated by poor running technique, and a lack of strength and control in the foot and calf muscles.

Both conditions can be resolved in a matter of weeks with a structured rehabilitation program like the ones found on this website. Our specialised 7-week online rehabilitation programs for both Osgood-Schlatter Disease and Sever’s Disease provide step-by-step guidance through this process, combining age-appropriate strengthening exercises, load management strategies, and movement skill retraining to help young athletes return to their sports confidently and safely without pain.

Learn more about the Osgood Training Program →

Learn more about the Sever’s Training Program →

Protecting Growth Plates

While growth plates are more vulnerable than mature bone, this doesn’t mean we should wrap our children in cotton wool. Instead, focus on creating an environment that supports healthy development while managing risks appropriately.

Key warning signs that warrant medical attention include persistent pain that doesn’t improve with rest, swelling around joints, limping, or pain that wakes your child at night. Any significant impact or injury to growth plate areas should be assessed by a medical professional.

Lifting Weights and Growth Plates

One of the most effective ways to protect growth plates is through properly structured strength training.

Despite the persistent myth that lifting weights can stunt growth, research consistently shows that supervised strength training is not only safe, but actively beneficial for growing bodies.

Strong muscles act as shock absorbers, reducing the impact forces that reach growth plates during activities like running and jumping. In fact, the forces experienced during typical strength training are significantly lower than those encountered during regular sports activities or playground play.

Not all strength training is created equal, however. The key is working with qualified coaches who are experienced in working with youth athletes and who can create age-appropriate programs that focus on proper technique and gradual progression. Combined with adequate nutrition and rest, this approach provides optimal support for healthy bone development and growth plate protection.

Better understand your child’s growth

With a better understanding of growth plates you are now equipped to support your child’s healthy development. By recognising conditions like Osgood-Schlatter Disease and Sever’s Disease early, you can take steps to manage them effectively and keep your child active and pain-free.

For more detailed guidance and information about these two conditions, read on with these blogs:

The secret to fixing Osgood Schlatters →

Managing Sever’s Disease Heel Pain →

Durham McInnis

Founder and Head Coach · Core Advantage

Our team has spent over a decade rehabilitating growth-related sports injuries in young athletes, and designed the Core Advantage Osgood & Sever's programs.