Best-evidence synthesis of risk factors for shoulder injury in overhead sports
| Risk factors | N, PS or number of AE | Type of sports | Acceptable/borderline quality (reference) | Association with risk ↑/↓/= (reference) | Best-evidence synthesis |
| Participation setting (competition vs training—non-specific injuries*) | AE=1 545 730 | Boys’ baseball | 37 44 | =37↑ 37 44 | Conflicting |
| AE=1 401 368 | Girls’ softball | 37 44 | =37↑ 37 44 | Conflicting | |
| AE=1 166 382 | Girls’ and women’s volleyball | 37 43 44 | =37 43↓44 | Conflicting | |
| Participation setting (competition vs training—non-traumatic injuries†) | AE=approximately 2 800 000 | Men’s baseball | 38 | ↑38 | Limited |
| AE=approximately 1 650 000 | Women’s softball | 41 | ↓41 | Limited | |
| AE=approximately 1 576 500 | Women’s volleyball | 35 | ↓35 | Limited | |
| Participation setting (competition vs training - traumatic injuries‡) | AE=approximately 5 678 028 | Men’s baseball | 38 42 | ↑38 42 | Limited |
| AE=approximately 3 294 365 | Women’s softball | 41 42 | =41 42 | Limited | |
| AE=approximately 3 213 533 | Women’s volleyball | 35 42 | ↑35 42 | Limited | |
| AE≥5 781 051 and 6528 PS | Men’s and women’s lacrosse | 15 39 42 46 | ↑15 39 42 46 | Limited | |
| Sex (males vs females— contact sports) | AE=1 910 078 and 6528 PS | Men’s and women’s ’ lacrosse, boys' and girls' lacrosse | 40 42 | ↑40 42 | Limited |
| n=336 | Men’s and women’s handball | 2 | =2 | Limited | |
| AE=not reported | Men’s and women’s water polo | 48 | ↓48 | Limited | |
| Sex (males vs females—non-contact sports) | AE=not reported | Men’s and women’s tennis | 48 | = 48 | Limited |
| Playing position (pitchers and catchers vs outfielders) | n=1020 | Youth baseball | 49 | ↑ 49 | Limited |
| External workload (higher number of training hours/week) | n=1020 | Youth baseball | 49 | ↑ 49 | Limited |
| History of shoulder pain | n=1020 | Youth baseball | 49 | ↑ 49 | Limited |
| History of elbow pain | n=1020 | Youth baseball | 49 | ↑ 49 | Limited |
| External workload (large increase in weekly training/match load) | n=679 | Youth handball | 50 | ↑ 50 | Limited |
| Biomechanics (GIRD) | PS=170 | Men’s baseball | 45 | =45 | Limited |
| Biomechanics (total ROM deficit) | PS=170 | Men’s baseball | 45 | =45 | Limited |
| Biomechanics (flexion deficit) | PS=170 | Men’s baseball | 45 | =45 | Limited |
| Biomechanics (insufficient external rotation) | PS=170 | Men’s baseball | 45 | ↑ 45 | Limited |
| Biomechanics (humeral torsion) | PS=255 | Men’s baseball | 47 | ↑ 47 | Limited |
No studies of high quality were identified. 1. Strong evidence: evidence provided by two or more high-quality studies and by generally consistent findings across these studies (≥75% of the studies reported consistent findings). 2. Moderate evidence: evidence provided by one high-quality study and/or multiple studies of acceptable quality and by generally consistent findings (≥75% of the studies reported consistent findings). 3. Limited evidence: evidence provided by one study of acceptable quality and/or one or more studies of borderline quality. 4. Conflicting evidence: inconsistent findings in multiple studies (<75% of the studies reported consistent findings). 5. No evidence: no admissible studies were found.
*Studies with no specific diagnosis reported.
†Tendinitis, overuse injuries.
‡Contusions, muscle tendon strains, shoulder subluxations, shoulder dislocations, ligament sprains, acromioclavicular joint sprains.
§No increased risk was seen for tendons strain.
↑, Associated with increased risk; =, no association; ↓, associated with decreased risk; AE, athletic exposure; GIRD, glenohumeral internal rotation deficit; N, number; PS, player season; ROM, range of motion.