The investigators hypothesize that the use of trunk (core) stabilization exercises early in treatment combined with lower extremity exercises will enhance the outcome over lower extremity exercises alone in the treatment of young athletes with anterior knee pain.

Inclusion Criteria:

• Subjects between 13-20 years of age clinically diagnosed with anterior knee pain.

• Pain should be peripatellar and should include at least 3 of the following:

  1. experienced during or after activity
  2. prolonged sitting
  3. with stair climbing or descending
  4. squatting
  5. kneeling.

• The subject should be active for at least 30 minutes per day.

Exclusion Criteria:

• Previous knee surgery
• Signs and symptoms of a specific structural diagnosis not consistent with AKP such as meniscal, ACL, PCL, or collateral ligament tears, pain referral from hip or lumbar spine (determined during examination), traumatic patellar dislocation, an inability to adequately understand or communicate in English.