Results of included studies
| Authors, study type, CASP score (%) | Population | Groin injuries | Hip ROM | Injury analysis | Re-injury | Outcomes | Conclusion | ||||
| Non-injured players n age | Injured players n/% age | Injuries n | Injured hips n/total % | Per hip/per player | Data presented PS, AH or BH | Reported/statistical check or correction | Mean (SD) values for injured/non-injured hip ROM of hips (of players), p value and OR, relative risk (95% CI) with p value | Mean difference | ROM risk factor or different | ||
| Arnason et al
26 PC, 92% | 294 24.0 (NR) | 17/6 NR | 32 | 13/498 3 | 1. ABD 2. EXT | Hips of I vs NI players | AH | Y / Y | 1. 40.9 (1.1)°/43.4 (0.2)°, p=0.08. OR 0.90 (95% CI 0.80 to 1.0, p=0.05) 2. 179.0 (0.3)°/176.5 (1.4)°, p=0.14. OR/RR: NR | 1. 3° 2. 3° | 1. Y 2. N |
| Verrall et al
30 PC, 92% | 29 21.4 (NR) | 4/14 NR | NR | NR NR | 1. IR 2. ER 3. Bilateral TR | Hips of I vs NI players | 1. AH 2. AH 3. BH | N / N | 1. 15.5 (2.1)/15.5 (1.3)° vs 21.8 (1.3)/20.8 (1.1)°, p=0.07/p=0.07. OR/RR:NR 2. 28.1 (1/9)/24.0 (1.4)° vs 30.7 (1.0)/29.9 (1.0)°, p=0.33/p=0.04. OR/RR:NR 3. 83.1 (4.3)°/103.2 (3.3)°, p=0.03. RR 0.90 (95% CI 0.83 to 0.99, p=0.03), robust SE 0.04, Z score −2.14 | 1. 6° 2. 5° 3. 20° | 1. N 2. N 3. Y |
| Engebretsen et al
19 PC, 77% | 506 23.9 (±0.2) | 51/10 24.8 (0.6) | 61 | 55/1016 5 | 1. IR 2. ER 3. FL 4. EXT 5. ABD | Hips of I vs NI players | PS | N / N | 1. 27.5 (2.0)°/29.8 (0.5)°, p=NR. OR 1.06 (95% CI 0.77 to 1.44, p=0.73) 2. 42.3 (1.8)°/46.3 (0.4)°, p=NR. OR=1.53 (95% CI 1.13 to 2.07, p<0.01) 3. 123.7 (1.5)°/120.8 (0.5)°, p=NR. OR=0.95 (95% CI 0.71 to 1.28, p=0.74) 4. 19.7 (1.1)°/20.9 (0.3)°, p=NR. OR 1.15 (95% CI 0.85 to 1.55, p=0.37) 5. 52.1 (1.6)°/51.0 (0.4)°, p=NR. OR 0.95 (95% CI 0.70 to 1.28, p=0.73) | 1. 2° 2. 4° 3. 3° 4. 1° 5. 1° | 1. N 2. Y 3. N 4. N 5. N |
| Emery et al
27 PC, 67% | a. 1292 (camp) b. 647 (season) NR | NR NR | a. 52 b. 152 | NR NR | 1. Bilateral ABD (active) | Hips of I vs NI players | BH | Y / Y | 1a. Camp: abduction <67.5°; RR 0.56 (95% CI 0.18 to 1.76, p=NR) 1b. Season: abduction <67.5°; RR 0.48 (95% CI 0.15 to 1.53, p=NR) | - | 1a. N 1b. N |
| Ibrahim et al
24 PC, 58% | 101 NR | 8/8 NR | 9 | NR NR | 1. TR | a. D hips of I vs NI players b. ND hips of I vs NI players c. I hips vs NI hips in I players | a. PS b. PS c. AH | Y / N | 1a+b. 44.7 (NR)°/53.7 (NR)°, (a. p=0.03; b. hip p=0.04). OR/RR: NR 1c. NR, p=0.06. OR/RR: NR | a. 9° b. 9° c. 3° | 1a. Y 1b. Y 1c. N |
| Tyler et al
28 PC, 58% | 47/17 (1/2 seasons FU) 23.0 (±4.3) | 8/17 | 11 | NR NR | 1. ABD | a. Hips of I vs NI players b. I hips vs NI hips | a. AH b. PS | Y / Y | 1a. (46.3 (10.3)°/45.8 (11.0)°, p=0.92). OR/RR: NR 1b. (46.3 (10.3)°/46.3 (9.2)°, p=0.69). OR/RR: NR | 1a. 2° 1b. 0° | 1a. N 1b. N |
| Witvrouw et al
29 PC, 58% | 146 | NR | 13 | NR | 1. ABD | Hips of I vs NI players | AH | N / N | 1. (51.3(NR)°/52.3(NR)°, p=0.45). OR/RR: NR | 1. 1° | 1. N |
| Nevin et al
31 CC, 71% | 18 23.9 (±3.2) | 18 23.8 (±3.6) | NA | 22 | 1. IR 2. ER 3. BKFO | a. I hips I players vs D hips of NI players b. NI hips I players vs ND hips NI players | PS | N / N | 1a. 30.6 (4.9)°/34.5 (5.6)°, p<0.05 1b. 28.6 (6.1)°/34.5 (5.9)°, p<0.05 2a. 27.2 (5.3)°/29.9 (4.5)°, p<0.05 2b. 26.5 (5.7)°/30.3 (4.7)°, p<0.05) 3a. 19.3 (4.3)cm/15.1 (3.8)cm, p<0.05 3b. 18.7 (3.4)cm/15.2 (4.3)cm, p<0.05 | 1a. 4° 1b. 6° 2a. 3° 2b. 4° 3a. 4 cm 3b. 4 cm | 1a. Y 1b. Y 2a. Y 2b. Y 3a. Y 3b. Y |
| Verrall et al
25 Case–control 57% | 42 NR | 47 NR | NA | NR | 1. Bilateral IR 2. Bilateral ER 3. Bilateral TR | Hips of I vs NI players | 1, 2, 3 BH | Y / N | 1. 36.7 (10.1)°/41.4 (11.3)°, p=0.03 2. 55.2 (10.5)°/60.3 (9.2)°, p=0.01 3. 91.3 (17.6)°/101 (17.1)°, p<0.01 | 1. 5° 2. 5° 3. 10° | 1. Y 2. Y 3. Y |
| Malliaras et al
22 Case–control 47% | 19 17.1 (±1.6) | 10 17.3 (±0.8) | NA | 18 | 1. IR 2. ER 3. Bilateral IR 4. Bilateral ER 5. BKFO | L+R hips of I vs NI players | PS | Y/N | 1. R 34.4 (8.1)/34.2 (11.6), p=0.96, L 32.7 (10.7)/33.3 (13.6), p=0.91 2. R 39.4 (8.7)/40.8 (7.1), p=0.66, L 46.2 (13.4)/48.3 (9.6), p=0.63 3. Not different, p=0.96 4. Not different, p=0.61 5. R 16.4 (4.8)cm/12.9 (5.1)cm, p=0.09, L 14.4 (3.8)/12.5 (4.7), p=0.28 | 1. R 0°/L 1° 2. R 1.5°/L 2° 3. NR 4. NR 5. R 4 cm/L 2 cm | 1. N 2. N 3. N 4. N 5. N |
| Rambani et al
23 Case–control 29% | 25 (18M/7F) 23.2(NR) | 25 (18M/7F) 22.8 (NR) | NA | 25 | 1. IR 2. ER 3. FL 4. ABD 5. ADD | Hips of I vs NI players | AH | N | 1. 17.4 (NR)°/40.9 (NR)°, p=0.03 2. 26.2 (NR)°/45.1 (NR)°, p=0.03 3. 122.3 (NR)°/122.2 (NR)°, p=NR 4. 35.2 (NR)°/35.9 (NR)°, p=NR 5. 27.1 (NR)°/26.20 (NR)°, p=NR | 1. 24° 2. 19° 3. 0° 4. 1° 5. 1° | 1. Y 2. Y 3. N 4. N 5. N |
Hip ROM refers to passive measures unless stated otherwise. Re-injury: a re-injury of one player during the study. Age presented as mean (SD)
Data presentation per side (PS) whether left(L)/right(R) or dominant(D)/non-dominant(ND), for all hips (AH) or both hips (BH) as sum scores of left and right.
ABD, abduction; ADD, adduction; BKFO, bent knee fall out; CASP, Critical Appraisal Skills Programme; CC, case-control study; corr, correction; ER, external rotation; EXT, extension; F, female; FL, flexion; I, injured; IR, internal rotation; M, male; N, no; NI, not injured; NR, not reported; OR, odd’s ratio; PC, prospective cohort study; RR, relative risk; TR, total rotation (IR+ER) per hip; Y, yes.