The purpose of this study is to compare three different treatments for these types of lower extremity apophysitis- Osgood-Schlatter syndrome (OSS), Sinding-Larsen and Johansson syndrome (SLJ), or Sever's disease.

The investigators hypothesize that adolescents who perform a home exercise program (HEP) consisting of active elongation exercises will have decreased pain and earlier return to sports and activities as compared to those who perform a HEP that consists of static stretching exercises or those who use symptomatic treatment with ice, acetaminophen or NSAIDs and activity modification.

Osgood-Schlatter syndrome (OSS), Sinding-Larsen and Johansson syndrome (SLJ), or Sever's disease are three types of apophysitis, or secondary growth center irritation, that frequently affect children and teens. Although these conditions are common, there is very little data from high quality studies to support a particular treatment method in affected patients. The purpose of this study is to compare three different treatments for these types of apophysitis. The investigators plan to compare two types of home exercise program (HEP), one involving active elongation exercises and one utilizing static stretching, with symptomatic treatment consisting of icing, over-the-counter medications and relative rest. The investigators hypothesize that the active elongation HEP will result in improvement in pain and earlier return to athletic activities when compared to the static stretching HEP and symptomatic care. This pilot study will recruit subjects at the Ann & Robert H. Lurie Children's Hospital outpatient sports medicine and orthopaedic clinics with any of the following types of lower extremity apophysitis: OSS, SLJ or Sever's disease. Subjects will complete a baseline evaluation and questionnaire and will be randomized into one of the three treatment groups. At 2, 4, 6, and 8 weeks, subjects from all groups will use a secure website to complete an online survey to complete questions regarding current pain level, compliance with their home exercise program, if applicable, use of other forms of treatment or pain management (e.g. splinting, icing, rest from activities) and current activity level. The investigators will compare results from each group to determine which treatment(s) resulted in the largest improvements in pain scores and the highest rates of participation in sports and recreational activities.

Inclusion Criteria:

• diagnosis of OSS, SLJ, or Sever's disease
• must have regular access to the Internet

Exclusion Criteria:

• history of prior treatment for OSS, SLJ, or Sever's disease
• history of previous injury to the affected joint requiring more than 1 week off of sports or activities