Table 3.
Strength of evidence for potential risk factors (prospective studies) included in qualitative synthesis.
| Potential Risk Factor | Study | Study Quality | Positive Findings | Level of Evidence |
|---|---|---|---|---|
| Anthropometrics | ||||
|
| ||||
| BMI | Backman et al. (2011) | Moderate | No | No evidence |
| de Vries et al. (2015) | Moderate | No | ||
|
| ||||
| Waist Circumference | Visnes and Bahr (2013) | Moderate | No | No evidence. |
|
| ||||
| Skin-fold Measures | Visnes and Bahr (2013) | Moderate | No | No evidence. |
|
| ||||
| Joint Range-of-Motion and Muscle Length | ||||
|
| ||||
| Ankle dorsiflexion ROM | Backman et al. (2011) | Moderate | Yes | Limited evidence for decreased ankle dorsiflexion ROM. |
|
| ||||
| Posterior Thigh Flexibility | Witvrouw et al. (2001) | Moderate | Yes | Limited evidence for decreased posterior thigh flexibility |
|
| ||||
| Quadriceps Flexibility | Witvrouw et al. (2001) | Moderate | Yes | Limited evidence for decreased quadriceps flexibility. |
|
| ||||
| Sports and Activity Related Factors | ||||
|
| ||||
| Activity Volume | de Vries et al. (2015) | Moderate | No | Conflicting evidence for increased activity volume. |
| Visnes et al. (2013) | Moderate | Yes | ||
| Backman et al. (2011) | Low | No | ||
| Hagglund et al. (2011) | Low | Yes | ||
|
| ||||
| Strength Training Volume | Visnes and Bahr (2013) | Moderate | No | No evidence. |
|
| ||||
| Jump Training Volume | Visnes and Bahr (2013) | Moderate | Yes | Limited evidence for greater volume of jump training per week. |
|
| ||||
| Sport Surface | de Vries et al. (2015) | Moderate | No | No evidence. |
| Hagglund et al. (2011) | Low | No | ||
|
| ||||
| Sport Specific Training Volume | Backman et al. (2011) | Low | No | No evidence. |
|
| ||||
| Volleyball Sets Played Per Week | Visnes and Bahr (2013) | Moderate | Yes | Limited evidence for greater number of volleyball sets played per week. |
|
| ||||
| Beach Volleyball Training Volume | Visnes and Bahr (2013) | Moderate | No | No evidence. |
|
| ||||
| Training Volume in Sports Other Than Primary Sport (Volleyball or Basketball) | de Vries et al. (2015) | Moderate | No | No evidence. |
| Visnes and Bahr (2013) | Moderate | No | ||
|
| ||||
| Training/Match Exposure Ratio | Hagglund et al. (2011) | Low | No | No evidence |
|
| ||||
| Functional Testing | ||||
|
| ||||
| CMJ Height | Visnes et al. (2013) | Moderate | Yes | Limited evidence for greater CMJ height in men. No evidence in women. |
|
| ||||
| Standing Jump Height | Visnes et al. (2013) | Moderate | No | No evidence. |
|
| ||||
| Muscle Performance | ||||
|
| ||||
| Knee Extension Torque | Witvrouw et al. (2001) | Moderate | No | No evidence. |
|
| ||||
| Knee Flexion Torque | Witvrouw et al. (2001) | Moderate | No | No evidence. |
|
| ||||
| Occupational Demands | ||||
|
| ||||
| Occupational Classification | de Vries et al. (2015) | Moderate | No | No evidence. |
|
| ||||
| Knee Loading During Work | de Vries et al. (2015) | Moderate | No | No evidence. |
BMI = Body mass index, ROM = Range-of-motion, CMJ = Counter-movement jump