Sever’s disease results from the fact that in children the bones grow faster than surrounding muscles, tendons and ligaments. In the lower leg there are two bones: the tibia and the fibia. At the back of the lower leg the Achilles Tendons join the calf muscles to the heel. If the lower leg bones grow faster than the calf muscles, the Achilles Tendon is placed under stress and tightens up, leading to pain and inflammation.
In addition, in children it takes time for bones to become totally ossified (turned into bone). In this case the soft cartilage at the back of the heel bone has not yet ossified, making it a potential weak spot. The constant pulling of the Achilles tendon at the not yet ossified heel bone (or growth plate) causes a traction injury at this weak spot.
A major contributing cause to Sever’s Disease is over-pronation: rolling in of the ankle joint and flattening of the arches.
Other contributing factors include stiffness in the lower limbs and foot tendons, rapid foot growth, use of faulty (unsupportive) footwear along with repeated minor injuries to the rear of the heel. At times, bone spur overgrowth with small fractures can be noticed in this part caused due to tension as well as injury to the heel bone.
Prolonged suffering from Sever’s disease makes many children vulnerable to several other ailments like knee problems or Osgood Schaltter’s disease, hip disorders called iliac apophysitis or elbow disorders like little leaguer’s elbow. These children are unable to tolerate the strain and stress of any physical activities or exercise. The joint between the growing part of the heel and the rest of the bone becomes extremely weak and therefore prone to breakage.