The aim of this study was to investigate the effect of specially produced insoles on biomechanical and gait parameters in children with Sever's disease.

Introduction: Sever's disease or calcaneal apophysitis is common in pediatric and adolescent patients and characterized by heel pain. Inflammation of apophysis in children of growing age causes microabrasion in bone cartilage joint. At the same time, the disease affects the self-limitation and affects the maturation of calcaneus.Sever's disease is an overuse syndrome and was described by James Warren Sever in 1912. The prevalence of Sever's disease varies between 2% and 16%.Sever's more common in children aged 8 - 15 years, but it was reported that heel pain increased during or after activity.This results in a shortening of the stance phase to remove the limb to avoid heel strikes during walking. Increased tension in the Achilles tendon and plantar fascia is affected by the mobility of the medial longitudinal arch of the foot and increases loading on the calcaneal cartilage. Stimulates foot alignment to pronation.

Different treatment have been described in Sever's disease. In the treatment program, stretching, strengthening exercises and ice application are recommended especially for gastrocnemius muscle and extensor muscle group.The traditional treatment approach is the restriction of the child's physical activity and sporting activities and rest until the symptoms have passed. In addition, orthoses can be used to treat the heel amplifier, anatomical dysregulation dominated by standing pronation. There is no previous study in order to investigate the effect of the specially produced insoles on the Sever's disease by changing the foot pressure center and the effect of the pronation on the gait parameters.

Subjects and methods:

The study is planned to be done with physical examination and radiological imaging of the patients who are between 8 and 15 years of age and diagnosed with Sever's disease. After the first physical examination evaluation, the foot rotation, step length, stance phase percentage, swing phase percentage, cadence and velocity parameters will be recorded with Zebris FDM -T (Force Distribution Measurement Treadmill) system. Zebris is a name of company in Germany.

Zebris Medical Limited ) is an innovative company that has been successful for many years in the development and production of 3D motion analysis and force measurement technologies for biomechanics. When the treadmill is in static and dynamic condition, strong pressure distribution measurement will be taken and personalized insole production according to foot pressure map will be done by orthosis prosthesis technician with Arch drafters Orthotics technology. After physiotherapist,decision, it will be delivered to the patients with the condition of being used outside and inside the home. Measurements related to pressure and gait parameters will be repeated after 4 weeks of use and home exercise (strengthening, stretching and eccentric exercise for the anterior lateral - posterior compartment of the foot ).

The spatio temporal gait parameters of the patients will be evaluated with Zebris (Zebris Medical Limited , Germany) FDM (Force Distribution Measurement ) treadmill system and pain levels at rest and during activity will be questioned using Visual Analog Scale.

Sample size: 40 professional athlete who are between 8 and 15 years of age for experimental group.

Inclusion Criteria:

• Aged between 8-15 years
• Calcaneal apophysitis with clinical symptoms and radiographic screening
• Positive squeeze test sign
• Heel pain more than 2 weeks

Exclusion Criteria:

• Intermittent heel pain to exclude plantar fasciitis pathology
• Another pathology within the same or the other foot for example fracture, achilles tendinitis and calcaneal bursitis
• Another pain symptom within the other part of the extremity