Objective To investigate the effect of a structured warm-up programme designed to reduce the incidence of knee and ankle injuries in young people participating in sports. Design Cluster randomised controlled trial with clubs as the unit of randomisation. Setting 120 team handball clubs from central and eastern Norway (61 clubs in the intervention group, 59 in the control group) followed for one league season (eight months). Participants 1837 players aged 15-17 years; 958 players (808 female and 150 male) in the intervention group; 879 players (778 female and 101 male) in the control group. Intervention A structured warm-up programme to improve running, cutting, and landing technique as well as neuromuscular control, balance, and strength. Main outcome measure The rate of acute injuries to the knee or ankle. Results During the season, 129 acute knee or ankle injuries occurred, 81 injuries in the control group (0.9 (SE 0.09) injuries per 1000 player hours; 0.3 (SE 0.17) in training v 5.3 (SE 0.06) during matches) and 48 injuries in the intervention group (0.5 (SE 0.11) injuries per 1000 player hours; 0.2 (SE 0.18) in training v 2.5 (SE 0.06) during matches). Fewer injured players were in the intervention group than in the control group (46 (4.8%) v (76 (8.6%); relative risk intervention group v control group 0.53, 95% confidence interval 0.35 to 0.81). Conclusion A structured programme of warm-up exercises can prevent knee and ankle injuries in young people playing sports. Preventive training should therefore be introduced as an integral part of youth sports programmes.

A set of exercises--the "11"--have been selected to prevent football injuries. The purpose of this cluster-randomized controlled trial was to investigate the effect of the "11" on injury risk in female youth football. Teams were randomized to an intervention (n=59 teams, 1091 players) or a control group (n=54 teams, 1001 players). The intervention group was taught the "11," exercises for core stability, lower extremity strength, neuromuscular control and agility, to be used as a 15-min warm-up program for football training over an 8-month season. A total of 396 players (20%) sustained 483 injuries. No difference was observed in the overall injury rate between the intervention (3.6 injuries/1000 h, confidence interval (CI) 3.2-4.1) and control group (3.7, CI 3.2-4.1; RR=1.0, CI 0.8-1.2; P=0.94) nor in the incidence for any type of injury. During the first 4 months of the season, the training program was used during 60% of the football training sessions, but only 14 out of 58 intervention teams completed more than 20 prevention training sessions. In conclusion, we observed no effect of the injury prevention program on the injury rate, most likely because the compliance with the program was low.

Objective: To assess the effect of a neuromuscular training program on the incidence of anterior cruciate ligament injuries in female team handball players. DESIGN: Prospective intervention study. Setting: Female team handball: Division I–III in Norway. Participants: Players from the top three divisions: control season (1998–1999), 60 teams (942 players); first intervention season (1999–2000), 58 teams (855 players); second intervention season (2000–2001), 52 teams (850 players). Intervention: A five‐phase program (duration, 15 min) with three different balance exercises focusing on neuromuscular control and planting/landing skills was developed and introduced to the players in the autumn of 1999 and revised before the start of the season in 2000. The teams were instructed in the program and supplied with an instructional video, poster, six balance mats, and six wobble boards. Additionally, a physical therapist was attached to each team to follow up with the intervention program during the second intervention period. Main Outcome Measures: The number of anterior cruciate ligament injuries during the three seasons and compliance with the program. Results: There were 29 anterior cruciate ligament injuries during the control season, 23 injuries during the first intervention season (OR, 0.87; CI, 0.50–1.52; P=0.62), and 17 injuries during the second intervention season (OR, 0.64; CI, 0.35–1.18; P=0.15). In the elite division, there were 13 injuries during the control season, six injuries during the first intervention season (OR, 0.51; CI, 0.19–1.35; P=0.17), and five injuries in the second intervention season (OR, 0.37; CI, 0.13–1.05; P=0.06). For the entire cohort, there was no difference in injury rates during the second intervention season between those who complied and those who did not comply (OR, 0.52; CI, 0.15–1.82; P=0.31). In the elite division, the risk of injury was reduced among those who completed the anterior cruciate ligament injury prevention program (OR, 0.06; CI, 0.01–0.54; P=0.01) compared with those who did not. Conclusions: This study shows that it is possible to prevent anterior cruciate ligament injuries with specific neuromuscular training.

The purpose of this study was to examine the injury incidence and pattern of injuries in youth female and male team handball players using two different prospective registration methods; match reports (90 teams, 1080 players) and coach reports (34 teams, 428 players). A total of 118 injuries were recorded by the coach report, of which 93 (79%) were acute injuries (incidence training: 0.9+/-0.16 injuries/1000 player hours; matches: 9.9+/-1.26; rate ratio vs training: 10.8 [95% confidence interval (CI) 7.0-16.6]; P<0.0001) and 25 (21%) were overuse injuries. Knee (26%) and ankle (24%) injuries accounted for half of the acute injuries (training: 0.5+/-0.12 injuries/1000/h; matches: 4.4+/-0.84; rate ratio vs training: 8.0 (95% CI 4.5-14.5); P<0.0001). No gender difference was found in the injury rate (rate ratio female vs male: 1.3 (95% CI 0.8-2.1); P=0.40). Most of the injuries occurred in the attacking phase by back or wing players doing a plant-and-cut, landing or turning movement, and more than half in contact situations with the opponent. Similar results were observed for acute match injuries in the match report. These results indicate that the rate of injuries in youth team handball is as high as at the senior level, and prevention should focus on knee and ankle injuries. The coach report seems to be the best method to register injuries in youth team handball to provide a full spectrum of injuries according to their type, incidence and severity.