State-Based Rehabilitation for Youth Athletes With Osgood-Schlatter or Sever-Related Apophyseal Pain

Inclusion Criteria: * Aged 10 to 17 years * Participates in organized sport and has at least 12 months of sport participation or training history * Has current or previous lower-extremity apophyseal pain consistent with Osgood-Schlatter-related knee pain and/or Sever-related heel pain * Meets criteria for at least one pre-specified rehabilitation entry pathway: * post-RCT rehabilitation entry after completion of the separate photobiomodulation trial, or * direct-entry rehabilitation with active symptoms, or * direct-entry rehabilitation with a history of Osgood-Schlatter-related or Sever-related symptoms and a low-irritability/residual presentation * For participants entering with active symptoms: * pain is located at the tibial tubercle region and/or the calcaneal apophyseal/heel region * pain is aggravated by activity or sport participation * pain is reproducible on clinical examination or history is consistent with the target condition * Participant and parent/caregiver are willing to take part in the rehabilitation program, including in-person visits, home exercises, and follow-up assessments * A parent or legal guardian provides written informed consent Exclusion Criteria: * Current pain episode started after an acute traumatic injury that better explains symptoms * Clinical presentation suggests a condition other than the target rehabilitation condition, including a major alternative knee or heel diagnosis requiring different management * Lower-limb sur…