Training in spikes and number of training hours correlate to injury incidence in youth athletics (track and field): A prospective 52-week study.

Objectives: The aim was to describe the annual incidence and types of musculoskeletal injuries, and to examine factors associated with injury risk.

Design: A 52-week prospective study in Swedish youth athletics aged 12-15 years.

Methods: Data on exposure to training and injury were collected from parents/caregivers and youth athletes using a web-survey system.

Results: A total of 101 (86%) youth athletes participated. Fifty-four (53%) of the athletes reported one new injury. Girls were at higher risk of sustaining an injury than boys (p = 0.048). Ninety-one percent of the new injuries were non-traumatic and 85% occurred in the lower extremities. Injuries to the front thigh represented 20% of the injuries. Cox proportional hazard regression analyses showed a six-fold increased risk for a first injury for athletes reporting use of spikes and training <6 h every two weeks (hazard ratio, 6.1; 95% confidence interval, 1.2-31.3) compared to athletes training <6 h using no spikes. Athletes training 6 h or more reporting use or no use of spikes had an eight-fold increase injury risk (p < 0.01).

Conclusions: Almost half of the youth athletes experienced a new injury and girls had a higher risk compared to boys. Nine out of ten injuries were related to overuse. An interesting observation was the high incidence of injuries to the quadriceps muscle complex. The study identified a correlation with training hours and an interaction with track spikes and risk of injury that needs further attention.