A one-season study of 58 male Norwegian academy players aged 12 to 19 found clinically diagnosed lower-limb apophyseal injuries in 12% of players in an average week, at 4.6 per 1,000 hours of exposure. Pubic apophysitis was the most common (32% of cases), and 77% of injuries had a gradual onset, with 81% starting during or just after training.
A questionnaire study of 735 children aged 7 to 15 at a Medical University of Warsaw dental clinic found 42.9% had a parent-reported history of traumatic dental injury, rising to 49.7% among those playing sports versus 31.3% among non-participants. Football participation, rural residence and lower parental education were also linked to higher reported injury. Clinic-based sampling means the figures are not population estimates.
Environmental heat stress reduced 30:15 Intermittent Fitness Test performance in highly trained male youth players. Across 642 tests from 312 players over two seasons, scores fell by about 0.4 km/h in low-risk heat (22 to 28 °C WBGT) and 1.5 km/h in high-risk heat (above 28 °C), with a decline of 0.09 to 0.15 km/h per 1 °C rise in WBGT.
A randomized controlled trial in 74 female soccer players found that a 9-week elastic band program, done twice weekly before in-season training, improved knee extension strength in the U19 group (about 132 N in both legs). Knee flexion gains in the U15 and Senior groups were marginal, vertical jump and change-of-direction speed barely changed, and strength gains faded after 3 weeks without training.
Researchers at Nationwide Children's Hospital found that youth aged 11 to 17 who averaged about 141 minutes of screen time a day in the first three days after a concussion recovered 35% faster than those with 260 minutes. Two hours a day of smartphone or TV use was linked to quicker recovery; computer, tablet and gaming use was not.
