| Author, year, study type (setting) | Participants and recruitment | Groups/intervention (compliance) | Outcomes (follow-up period) | Comments |
| Emery 2005 Cluster RCT (Canada) | 120 subjects (aged 14–19; with no history of musculoskeletal injury or medical condition). Computer-generated random recruitment of schools and students (2 males and 2 females from PE programme roster in grades 10–12) | (A) Balance training (n = 60 players): physiotherapist taught each participant a home-based, proprioceptive balance training programme; performed 20 min/day for 6/52, then weekly for remainder of 6/12 period. (B) No intervention (n = 60 players). (Self-reported compliance: daily record sheet with weekly phone call over 6/52 training period). | Injury definition: any injury requiring medical attention or loss of 1 or more days of sporting activity or both. Severity classification: classified by area and type (sprain, fracture, etc) of injury. (6 months). Authors’ conclusion: positive: wobble board reduced self-reported injury | Data collection methods: injury report forms; completed by subject and by any attending medical professional. The physiotherapist made biweekly phone calls to all participants to ensure all eligible injuries reported. |
| Wedderkopp 1999 Cluster RCT (Denmark) | 237 female handball players (aged 16–18; playing at elite, intermediate, recreational levels). Randomised for intervention. Controlled for age, practice time, playing level, floor composition and injury incidence in previous season (self-reported, assessed with survey). | (A) Intervention protocol (11 teams; n = 111 players): various functional activities followed by use of ankle disc for 10–15 min at all practice sessions. (B) Control (11 teams; n = 126 players): subjects continued to practice as usual. (Compliance: not reported). | Injury definition: any injury causing the player to miss the next game or practice, or to play with considerable discomfort. Severity classification: absence from practice/games. Minor: <1 week. Moderate: 1 week but <1 month. Major: >1 month. (August–May 1996; 10 months). Authors’ conclusion: positive: intervention group reduced injury. | Data collection methods: coaches documented injury incidence and severity by questionnaire. Injury verification: club physiotherapist and doctor. |
| Wedderkopp 2003 Cluster RCT (Denmark) | 163 female European handball players (aged 14–16; playing at elite, intermediate and recreational levels). Randomised by team (8 to each group). | (A) Functional training and ankle disk (n = 77 players): performed for 10–15 min at each training session plus strength activities. (B) Functional training only (n = 8 teams; 86 players) (Compliance: not reported) | Injury definition: any injury causing the player to miss the next game or practice, or to play with considerable discomfort. Severity classification: absence from practice/games. Minor: 1 week. Moderate: >1 week but <1 month. Major: >1 month. (1 season). Authors’ conclusion: positive: ankle disc reduced traumatic injury when added to functional strength training. | Data collection methods: investigators contacted coaches at least once a week. Injury verification: injured players contacted and interviewed by doctor. Examined if in doubt. |
| Olsen 2005 Cluster RCT (Norway) | 1837 youth handball players (aged 15–17; 1586 female, 251 male); 123 volunteer clubs. Block randomisation to intervention or control group. Clubs matched by region, playing level, sex and numbers of players. | (A) Technical, balance and strengthening exercises (61 clubs; 958 players; 808 female, 150 male): structured 20 min group programme (warm-up, technical, balance and strengthening exercises). Performed before first 15 training sessions, then weekly for rest of season. (full details on each facet of warm-up described). (B) Control (59 clubs; 879 players; 778 female, 101 male): subjects advised to continue training as usual. (Compliance reported by coach of each team). | Injury definition: classified as acute or overuse injury to knee or ankle. Severity classification: absence from practice/games. Slight: 0 days. Minor: 1–7 days. Moderate: 8–21 days. Major: >21 days. (1 league season 8 months). Authors’ conclusion: positive: an injury prevention protocol can prevent injuries in youth handball. | Data collection methods: injury and exposure reported by physiotherapists (blinded to group allocation) each month. Injury data confirmed by coaches at end of season. |
| Junge, 2002 Prospective intervention study (Switzerland) | Male soccer; age 14–19; 14 teams (3 high skill + 4 low skill level amateur youth teams in each group). Group allocation by geographic location (2 regions). | (A) Intervention group: general education and supervision of coaches + players. (Preventative intervention included: warm-up, cool-down, taping, rehabilitation, fair play and flexibility/stability exercises). (B) Control: subjects trained and played soccer as usual. (Physiotherapists delivered the primary intervention. Amount of training and matches was recorded for each player by coaches.) | Injury definition: any physical complaint caused by soccer that lasted for more than 2 weeks or resulted in absence from a subsequent match or training session. Severity classification. Mild: absence up to 1 week or complaints for >2 weeks. Moderate: absence for >1 week but <4 weeks. Severe: absence for at least 4 weeks or severe tissue damage, eg, fracture/dislocation (1 year). Incidence of injury per 1000 h. Authors’ conclusion: positive: injury prevention intervention reduced injury. | Data collection methods/injury verification: doctors visited participants weekly to perform an interview and physical examination of injury. Type, severity and location of injury also documented. |
| Mandelbaum 2005 Prospective intervention study (USA) | 1041 female competitive youth soccer players (age 14–18). Non-randomised teams volunteered for inclusion. | (A) Injury prevention protocol (n = 1041 (2000); n = 844 (2001); all female): warm-up, stretching and strengthening, plyometric activities, and soccer-specific agility drills. (B) Control (n = 1905 (2000); n = 1913 (2001)): continued traditional warm-up. Age and skill matched controls. (Compliance form for each team completed by coach with a spot check on last week of season). | Injury definition: study focused on non-contact ACL injuries. Severity classification. (2 years 2000–2001). Authors’ conclusion: positive: a neuromuscular training programme led to a significant reduction in ACL injuries in female soccer players. | Data collection methods: injuries reported by coach on a weekly injury report form to project coordinator. If knee injury occurred, player was given a “knee injury questionnaire” to complete within 10 days and return to project coordinator. Injury verification: confirmed by doctor and MRI or arthroscopy. |
ACL, anterior cruciate ligament; RCT, randomised controlled trial.