Background Over the past two decades, sports medicine research has developed innovative and proven interventions for injury prevention in athletes. Intervention effectiveness of any injury prevention exercise programme (IPEP) is influenced by both utilisation and exercise fidelity, but this has rarely been evaluated in previous randomised controlled trials (RCT).

Objective To describe the exercise fidelity and utilisation fidelity of the Knee Control IPEP in youth floorball alongside an intervention RCT.

Design Observation study, 26-week season.

Setting Swedish youth floorball.

Patients (or Participants) 20 teams (8 female, 12 males) aged 12–17 years.

Interventions (or Assessment of Risk Factors) Knee Control IPEP.

Main Outcome Measurements Exercise fidelity and program utilisation fidelity.

Results Of the 535 individual Knee Control exercises observed, 76% were performed by males; and 58% exercises were performed correctly. Exercise fidelity was greater in females (71% vs 54%, P=0.001). No difference in exercise fidelity during the first (57%) and second (59%) half of the season. The full Knee Control IPEP (7 exercises x 3 sets) was completed as prescribed in only four out of 31 team training sessions observed. Utilisation fidelity did not differ between sexes and the average number of completed exercises performed was 11(±5). Males performed more exercises with a higher level of difficulty (n=247, 93 and 59 for levels A, B and C+D, respectively) compared to females (n=88, 26, and 7, P=0.021). 33% of the coaches perceived that they had good knowledge about injury prevention, only 33% believed regular IPEP use could decrease injury risk.

Conclusions The exercise fidelity was low with only three out of five exercises observed performed according to instructions. Only half of the total programme exercises were being executed. Only a third of coaches believed IPEP can reduce injury risk; thus current delivery strategies might be insufficient for translating evidence to this key-stakeholder group. Future work is needed to inform evidence-based strategies to better support the implementation of IPEPs in sport settings.