Table 1 TIDieR checklist for reporting of interventions

Exercise therapy and patient education

This multimodal program has never been tested in young adolescents with PFP, only among 15–19 year olds with PFP.

One physiotherapist delivered the patient education, exercise therapy, and instructions on patellar taping. The exercise therapy was based on previous trials and consisted of a combination of supervised group training sessions and unsupervised home-based exercises.

Physiotherapist

Face to face

At the hospital

The unsupervised home exercises consisted of approximately 15 min of quadriceps and hip muscle retraining and stretching and were performed every day except for the days of supervised sessions. The supervised exercises were offered three times per week at the hospital for 13 weeks. Full description of intervention can be seen in this open access publication [3]

To progressively match the exercise level to the performance level and pain levels of each participant, all exercises were available in multiple levels of difficulty.

All adolescents started with exercises at level 1 and progressed from there. The progression followed previously described rules. (1) Good quality of movement determined by the physiotherapist. ‘Good quality’ is defined as able to control hip, knee, and foot alignment during exercises with both extra-slow and slightly faster than normal movement. (2) Ability to perform the actual number of repetitions as defined in the training protocol.

(3) No self-reported increase in usual pain after the training session or the next morning.

Adherence to the supervised sessions was recorded as attendance. The adolescents participated in a median of 16 (IQR 5.5–25) supervised training session during the 13 weeks