Skip to main content
. 2017 Sep 21;3(1):e000263. doi: 10.1136/bmjsem-2017-000263

Table 2.

Summary of synthesis of prognostic factors for all injury outcomes with associated GRADE evaluation

Adapted GRADE criteria
Injury type Specific Outcomes Potential prognostic factors Number of studies Authors Effect measure Univariate Effect size (95%  CI) Multivariate effect size (95%  CI) Study limitations Consistency of results Effect size Precision of results Publication bias Overall quality
Muscle injuries Hamstring injuries Increasing age 2 Hagglund et al 36 37 HR Figure 2 1.1 (1 to 1.2) Many No Small Imprecise Likely Low
Increasing age 2 Arnason et al,30 Henderson et al 39 OR – Figure 3 Many Yes Small Precise Likely Low
Previous hamstring injury 2 Hagglund et al 36 37 HR Figure 2 Figure 2 Many Yes Moderate Imprecise Likely Low
Previous hamstring injury 2 Arnason et al,30 Fousekis et al 34 OR 7.42 (2.9 to 19) Figure 3 Very many No Variable Imprecise Likely Very low
Stature (above mean) 1 Hagglund et al 37 HR 0.82 (0.68 to 1.0) – Many N/A Small Imprecise Likely Very low
Previous quadriceps injury 1 Hagglund et al 37 HR 1.44 (1.08 to 1.93) – Very many N/A Small Imprecise Likely Very low
Eccentric hamstring strength asymmetries 1 Fousekis et al 34 OR – 3.88 (1.13 to 13.23) Very many N/A Moderate Imprecise Likely Low
BW adjusted eccentric hamstring strength (60  deg/s) 1 Van Dyk et al 42 OR – 1.37 (1.01 to 1.85) Many N/A Small Imprecise Likely Very low
BW adjusted concentric quadriceps strength (60  degree/s) 1 Van Dyk et al 42 OR – 1.41 (1.03 to 1.92) Many N/A Small Imprecise Likely Very low
Active hip flexion ROM (dominant leg) 1 Henderson et al 39 OR – 0.77 (0.62 to 0.97) Many N/A Small Imprecise Likely Low
Increased NCMJ height 1 Henderson et al 39 OR – 1.47 (1.02 to 2.12) Many N/A Small Imprecise Likely Low
Functional leg length asymmetry 1 Fousekis et al 34 OR – 3.8 (1.08 to 13.33) Very many N/A Large Imprecise Likely Low
Position: goalkeeper 1 Hagglund et al 37 HR 0.11 (0.06 to 0.23) 0.11 (0.06 to 0.24) Very many N/A Large Imprecise Likely Very low
Time of season:
September-November 1 Hagglund et al 37 OR 2.24 (1.34 to 3.74) 2.16 (1.29 to 3.60) Very many N/A Moderate Imprecise Likely Very low
December–February 1 Hagglund et al 37 OR 2.56 (1.54 to 4.26) 2.55 (1.53 to 4.24) Very many N/A Moderate Imprecise Likely Very low
March–May 1 Hagglund et al 37 OR 2.56 (1.54 to 4.28) 2.49 (1.49 to 4.17) Very many N/A Moderate Imprecise Likely Very low
Playing league matches with ≤4  days recovery 1 Bengtsson et al 31 RR – 1.28 (1.06 to 1.56) Many N/A Small Imprecise Likely Very low
Venue: away match 1 Hagglund et al 37 OR 0.75 (0.62 to 0.91) 0.76 (0.63 to 0.92) Very many N/A Small Imprecise Likely Very low
Quadriceps injuries Previous adductor injury 1 Hagglund et al 37 HR 1.88 (1.31 to 2.69) 1.68 (1.16 to 2.41) Very many N/A Small Imprecise Likely Very Low
Previous quadriceps injury 1 Hagglund et al 37 HR 3.47 (2.49 to 4.84) 3.1 (2.21 to 4.36) Very many N/A Large Imprecise Likely Very low
Previous calf injury 1 Hagglund et al 37 HR 2.08 (1.37 to 3.17) 1.91 (1.24 to 2.93) Very many N/A Moderate Imprecise Likely Very low
Position: goalkeeper 1 Hagglund et al 37 HR 0.46 (0.23 to 0.9) 0.41 (0.2 to 0.82) Very many N/A Moderate Imprecise Likely Very low
Playing league matches with ≤4  days recovery 1 Bengtsson et al 31 RR – 1.8 (1.19 to 2.72) Many N/A Small Imprecise Likely Very Low
Match type: UEFA CL 1 Hagglund et al 37 OR 0.51 (0.25 to 1.01) 0.48 (0.24 to 0.97) Very many N/A Moderate Imprecise Likely Very low
Adductor injuries Previous adductor injury 1 Hagglund et al 37 HR 1.48 (1.06 to 2.06) 1.40 (1 to 1.96) Very many N/A Small Imprecise Likely Very low
Position: goalkeeper 1 Hagglund et al 37 HR 0.58 (0.33 to 0.99) 0.51 (0.29 to 0.91) Very many N/A Moderate Imprecise Likely Very low
Venue: away match 1 Hagglund et al 37 OR 0.56 (0.43 to 0.73) 0.56 (0.43 to 0.73) Very many N/A Moderate Imprecise Likely Very low
Match type: other cup 1 Hagglund et al 37 OR 0.60 (0.37 to 0.97) – Very many N/A Moderate Imprecise Likely Very low
Groin strain injuries Previous groin strain 1 Arnason et al 30 OR 5.71 (2 to 15.9) 7.3 (2.3 to 23.2) Many N/A Large Imprecise Likely Low
Reduced ROM hip abduction 1 Arnason et al 30 OR – 0.9 (0.8 to 1) Many N/A Small Imprecise Likely Very Low
Calf muscle injuries Previous calf muscle injury 1 Hagglund et al 37 HR 2.83 (1.86 to 4.31) 2.33 (1.52 to 3.57) Very many N/A Moderate Imprecise Likely Very low
Increasing age 1 Hagglund et al 37 HR 2.02 (1.45 to 2.82) 1.93 (1.38 to 2.71) Very many N/A Moderate Imprecise Likely Very low
Previous adductor injury 1 Hagglund et al 37 HR 1.87 (1.26 to 2.77) 1.71 (1.15 to 2.55) Very many N/A Small Imprecise Likely Very low
Previous hamstring injury 1 Hagglund et al 37 HR 2.1 (1.51 to 2.54) 1.74 (1.24 to 2.44) Very many N/A Small Imprecise Likely Very low
Match type: UEFA CL 1 Hagglund et al 37 OR 2.43 (1.61 to 3.67) 2.72 (1.78 to 4.14) Very many N/A Moderate Imprecise Likely Very low
Position: goalkeeper 1 Hagglund et al 37 HR 0.43 (0.2 to 0.96) 0.36 (0.16 to 0.82) Very many N/A Moderate Imprecise Likely Very low
Ligament injuries Ankle sprain Previous ankle sprain* 2 Arnason et al, 30 Faude et al 33 OR Figure 4 Figure 4 Many No Large Imprecise Likely Very low
Weight above median 1 Fousekis et al 35 OR – 5.72 (1.37 to 23.95) Many N/A Large Imprecise Likely Very low
BMI > median 1 Fousekis et al 35 OR – 8.16 (1.42 to 46.63) Many N/A Large Imprecise Likely Very low
Eccentric ankle strength asymmetry >15% 1 Fousekis et al 35 OR – 8.88 (1.95 to 40.36) Many N/A Large Imprecise Likely Very low
Playing three matches within4  days 1 Carling et al 32 IRR 10.4 (1.9 to 57.9) – Many N/A Large Imprecise Likely Very low
Knee sprain Previous knee sprain* 2 Arnason et al 30 Faude et al 33 OR Figure 4 Figure 4 Many No Moderate Imprecise Likely Very low
ACL tear Previous ACL tear† 1 Faude et al 33 OR – 5.24 (1.42 to 19.59) Many N/A Large Imprecise Likely Very low
Tendinopathy Patellar tendinopathy Age 1 Hagglund et al 38 OR – 0.97 (0.93 to 1.01) Very many N/A Small Imprecise Likely Very low
Increased body weight (per 5  kg) 1 Hagglund et al 38 OR – 1.15 (1 to 1.33) Very many N/A Small Imprecise Likely Very low
Total football exposure hours (per 10  hours increase) 1 Hagglund et al 38 OR No data 1.02 (1 to 1.04) Very many N/A Small Imprecise Likely Very low
Injuries defined by anatomical location Traumatic knee injuries Previous ACL injury‡ 1 Waldén et al 41 Rel. R – 2.6 (1.1 to 6.7) Very many N/A Moderate Imprecise Likely Very low
Previous ACL injury§ 1 Waldén et al 41 Rel. R – 2.7 (1.3 to 5.8) Very many N/A Moderate Imprecise Likely Very low
Previous knee injury 1 Hagglund et al 36 HR – 3.10 (1.3 to 7.6) Very many N/A Moderate Imprecise Likely Very low
Overuse knee injuries Previous ACL injury ‡ 1 Waldén et al 41 Rel. R – 7.9 (3.4 to 18.5) Very many N/A Large Imprecise Likely Very low
Previous ACL injury§ 1 Waldén et al 41 Rel. R – 4.8 (2.0 to 11.2) Very many N/A Large Imprecise Likely Very low
Thigh injuries Increased BMI 1 Nilstad et al 40 OR 1.37 (0.95 to 1.98) 1.51 (1.08 to 2.11) Few N/A Small Imprecise Likely Very low
Knee injuries Previous ACL injury ‡ 1 Waldén et al 41 Rel. R – 4.5 (2.3 to 8.8) Very many N/A Large Imprecise Likely Very low
Previous ACL injury§ 1 Waldén et al 41 Rel. R – 3.4 (1.8 to 6.3) Very many N/A Moderate Imprecise Likely Very low
Ankle injuries Age 1 Nilstad et al 40 OR 0.64 (0.44 to 0.95) 0.65 (0.4 to 1.05) Few N/A Small Imprecise Likely Very low
Increased 1 RM leg press 1 Nilstad et al 40 OR 1.47 (1.05 to 2.05) 1.41 (0.97 to 2.06) Few N/A Small Imprecise Likely Very low
Foot pronation 1 Nilstad et al 40 OR 1.56 (1.13 to 2.15) 1.55 (0.99 to 2.41) Few N/A Small Imprecise Likely Very low
Reduced knee valgus angle 1 Nilstad et al 40 OR 1.14 (0.49 to 2.66) 0.64 (0.41 to 1) Few N/A Moderate Imprecise Likely Very low
Lower leg/foot injuries Previous knee injury 1 Nilstad et al 40 OR 3.73 (1.47 to 9.46) 3.57 (1.27 to 9.99) Few N/A Large Imprecise Likely Low
Increased BMI 1 Nilstad et al 40 OR 1.44 (0.84 to 2.49) 1.4 (0.90 to 2.17) Few N/A Small Imprecise Likely Very low
Increased age 1 Nilstad et al 40 OR 1.48 (1 to 2.21) 1.47 (0.98 to 2.2) Few N/A Small Imprecise Likely Very low
Groin injuries Previous groin injury 1 Hagglund et al 36 HR 2.40 (1.2 to 4.6) – Very many N/A Small Imprecise Likely Very low

RR, rate  ratio; Rel. R, relative  risk; IRR, incidence  rate ratio; BMI, body  mass index; ACL, anterior cruciate ligament; BW, body  weight; N/A, not available; GRADE, Grading of Recommendations Assessment, Development and Evaluation; NCMJ, non-countermovement jump; RM, repetition  maximum; UEFA CL, UEFA Champions League match;

Effect size and CIs in bold indicate significant value. Effect sizes and CIs in normal font indicate non-significant result. Effect sizes classed as small if measures between 0.66–1 and 1 – 2.4, moderate 0.33–0.66 and 2.5 – 4.4, large 0–0.33  and ≥4.5.

*Arnason et al 30 investigated male subjects, whereas Faude et al 33 investigated female subjects—see figure 4 for details.

† Faude et al 33 have investigated female participants only.

‡Denotes where knee used as unit of analysis,

§ Denotes where player used as unit of analysis.