Demographics of the footballer and general population groups
| Footballers | General population | p Value | |
| Questionnaires, n | 1207 | 4085 | |
| Age (years), mean (SD) | 59.0 (11.7) | 62.9 (10.4) | <0.001** |
| BMI (kg/m2), mean (SD) | 27.3 (3.2) | 27.5 (4.7) | 0.139 |
| Right handed, n (%) | 1057 (87.6) | 3474 (85.0) | 0.529 |
| Right lower limb dominance, n (%) | 1000 (82.85) | N/A | N/A |
| Pattern 3 digit ratio, n (%) | 733 (60.7) | 2237 (54.8) | 0.003** |
| Nodal osteoarthritis, n (%) | 86 (7.1) | 218 (5.6) | <0.001** |
| Knee injury, n (%) | 778 (64.5) | 953 (23.3) | <0.001** |
| High-risk occupation, n (%) | 742 (61.5) | 2185 (53.5) | <0.001** |
| Malalignment, n (%) † | |||
| Constitutional | 193 (16.0) | 278 (6.8) | <0.001** |
| Current | 289 (24.6) | 434 (11.2) | <0.001** |
| Proportion with change in alignment since 20s, (%) | |||
| Varus | 88 (8.9) | 132 (3.7) | <0.001** |
| Valgus | 32 (3.2) | 42(1.2) | |
| Body pain, n (%)‡ | 901 (74.7) | 2574 (69.8) | 0.001** |
| Painkillers, n (%) § | 423 (35.0) | 1289 (31.6) | 0.02* |
| Comorbidities, n (%)¶ | 355 (29.4) | 1868 (45.7) | <0.001** |
*p<0.05, **p<0.01.
†Malalignment: right knee varus or valgus deformities (symmetry assumed).
‡Pain reported in any region of the body for most days of the past month.
§Painkillers include non-steroidal anti-inflammatories, opioids, over-the-counter medications and auxiliary medications that have a pain-relieving effect.
¶Comorbidities: diabetes/hypertension/ myocardial infarction/cancer/fibromyalgia.