Baseline demographic and MRI characteristics. Values are presented as mean (±SD) or median (IQR) as appropriate for continuous variables and as frequency (%) for categorical variables
| n=70 | |
| Age (years) | 24 (IQR: 21–30) |
| Sport | |
| Athletics | 3 (4.3%) |
| Basketball | 2 (2.9%) |
| Decathlon | 1 (1.4%) |
| Football | 55 (78.6%) |
| Futsal | 5 (7.1%) |
| Handball | 2 (2.9%) |
| Hockey | 1 (1.4%) |
| Volleyball | 1 (1.4%) |
| Level of participation | |
| Professional | 69 (98.6%) |
| Competitive | 1 (1.4%) |
| Side of injury | |
| Right | 36 (51.4%) |
| Left | 34 (48.6%) |
| Muscle injured | |
| Biceps femoris (long head) | 56 (80.0%) |
| Biceps femoris (short head) | 0 (0.0%) |
| Semitendinosus | 2 (2.9%) |
| Semimembranosus | 12 (17.1%) |
| MRI grade | |
| Grade 1 | 34 (48.6%) |
| Grade 2 | 36 (51.4%) |
| Oedema dimensions | |
| Craniocaudal length (cm) | 16.4±6.5 |
| Cross-sectional area (cm2) | 17.6 (IQR: 6.3–38.9) |
| Volume (cm3) | 53.9 (IQR: 14.6–110.1) |
| Distance to ischial tuberosity (cm) | 9.4 (IQR: 3.2–16.3) |
| Intramuscular tendon involvement | |
| No intramuscular tendon disruption | 41 (58.6%) |
| Intramuscular tendon disruption | 29 (41.4%) |
| <50% of tendon CSA | 5 (17.2%) |
| 50%–99% of tendon CSA | 12 (41.4%) |
| 100% of tendon CSA | 12 (41.4%) |
| Biceps femoris (long head) | 17 (58.6%) |
| Biceps femoris (long head) and semitendinosus | 7 (24.1%) |
| Semimembranosus | 5 (17.2%) |
| Longitudinal tendon disruption | |
| Length of intramuscular tendon disruption (cm) | 6.6±2.2 (n=17) |
| Retraction (cm) | 4.4±3.2 (n=12) |
| Waviness | |
| Present | 17 (24.3%) |
| Absent | 53 (75.7%) |
CSA, cross-sectional area.