Sever’s Disease is a serious type of ‘growing pain’ rooted in the fact that the rate of growth of a child’s heel bones is slower than that of the ligaments of the leg. The heel bone is one of the first bones in the human body to reach full size, and it is prone to injury because it is not flexible or elastic. As a child goes through growth spurts of the heel bone, the Achilles tendon, which connects the calf muscle to the heel, may be struggling to play catch-up, due to its slower rate of growth. In this scenario, the tendon and leg muscles can become strained, tight and over-stretched. As the child walks, runs or plays, repetitive pressure is placed on the tendon, and the tension can cause damage to the growing heel bone, resulting in pain and inflammation.
At birth, most of our foot bones are still made of cartilage, which ossifies (becomes bony) over the first few years of life. At the back of the heel, there is a growth plate that is attached to the main body of the heel bone by a cartilaginous join. At about the age of 14-15 years, this area of cartilage between the growth plate and the heel bone ossifies, fusing the area to the heel. Sever?s disease occurs when there is too much motion or strain across the growth plate, resulting in this area becoming inflamed and painful.
Pain is usually related to activity levels. In most cases the posterior aspect of the calcaneus will be tender. Checking both the medial and lateral aspects of the posterior portion of the growth plate will often show tenderness. Occasionally, the plantar aspect may be tender or both of these locations may be found to be tender. Frequently the Achilles tendon is tight and there may have been a recent increase in activity. The factors contributing to this disorder are similar to those causing plantar fasciitis, but a tight Achilles tendon appears to be a greater contributor than pronation.
Sever?s disease can be diagnosed based on your history and symptoms. Clinically, your physiotherapist will perform a “squeeze test” and some other tests to confirm the diagnosis. Some children suffer Sever?s disease even though they do less exercise than other. This indicates that it is not just training volume that is at play. Foot and leg biomechanics are a predisposing factor. The main factors thought to predispose a child to Sever?s disease include a decrease in ankle dorsiflexion, abnormal hind foot motion eg overpronation or supination, tight calf muscles, excessive weight-bearing activities eg running.
Non Surgical Treatment
Sever?s disease is believed to be the byproduct of repepitive stress and trauma to the growth plate in the calcaneous, or heel bone. The stress is from the pull of the Achilles tendon on the growth plate where the tendon attaches.
This condition is self limiting, it will go away when the two parts of bony growth join together, this is natural. Unfortunately, Sever’s disease can be very painful and limit sport activity of the child while waiting for it to go away, so treatment is often advised to help relieve it. In a few cases of Sever’s disease, the treatment is not successful and these children will be restricted in their activity levels until the two growth areas join, usually around the age of 16 years. There are no known long term complications associated with Sever’s disease.