Background High-intensity sports like Squash expose immature athletes to the risk of developing Osgood-Schlatter's (OSD) disease during critical periods of growth. Acute OSD episodes have been associated with changes in training load and recognized as a common cause of lost training days.

Objective To investigate the influence of periodic OSD monitoring and any subsequent alterations in training load on the number of training days lost.

Design Prospective data analysis over 2 seasons (80 weeks), repeated measures.

Setting Elite youth sports academy.

Patients (or Participants) Highly-trained adolescent Squash athletes (n=9) who were identified as being “at risk” based on; previous episodes of OSD, chronological age (12–15 years) and maturity status.

Interventions (or Assessment of Risk Factors) On a weekly basis a physiotherapist graded each athlete on a scale of 5 (“free of OSD symptoms”) to 1 (“unable to train”). The grading was based on clinical assessments including; pain level over the tibial tuberosity during palpation, functional movements, and strength assessments of the Quadriceps and Hamstrings. When an athlete was rated ≤3 coaching staff were advised to reduce the training load for the subsequent week. Training load was quantified using Edwards Training Impulse calculated from heart rate data.

Main Outcome Measurements The number of training days lost due to OSD. Any alterations in training load following a rating of ≤3.

Results Over the intervention period there were 24 ratings of ≤3. Weekly training load following a rating of ≤3 was significantly lower than the average weekly load (245.4±231.2 Vs. 658.5±154.7 arbitrary units, P<0.001). Five training days lost due to OSD were recorded during the intervention period.

Conclusions Periodic monitoring of OSD symptoms, with basic clinical tests, appear to alert the medical staff about potential acute onsets. Subsequent recommendations to reduce training load resulted in low training days lost due to OSD.