Table 1

Baseline characteristics of patients*

Platelet-rich plasma group
(n=30)
Platelet-poor plasma group
(n=30)
No injection group
(n=30)
Age (years)26.6±5.9
26.3 (21.2–31.4)
25.6±5.8
24.9 (22.1–29.3)
25.5±5.7
24.3 (20.7–29.4)
Male gender30 (100.0)30 (100.0)30 (100.0)
Sports category
 Athletics0 (0.0)2 (6.7)2 (6.7)
 Basketball1 (3.3)1 (3.3)0 (0.0)
 Decathlon1 (3.3)0 (0.0)0 (0.0)
 Football22 (73.3)22 (73.3)22 (73.3)
 Futsal3 (10.0)3 (10.0)2 (6.7)
 Handball1 (3.3)1 (3.3)1 (3.3)
 Hockey1 (3.3)0 (0.0)1 (3.3)
 Physical coach football0 (0.0)0 (0.0)1 (3.3)
 Squash0 (0.0)1 (3.3)0 (0.0)
 Volleyball0 (0.0)0 (0.0)1 (3.3)
 Weightlifting and bodybuilding1 (3.3)0 (0.0)0 (0.0)
Level of sports
 Professional30 (100)28 (93.3)29 (96.7)
 Competitive0 (0)2 (6.7)1 (3.3)
Sprinting type of injury14 (46.7)20 (66.7)22 (73.3)
Previous hamstring injuries19 (63.3)15 (50.0)15 (50.0)
Previous ipsilateral hamstring injuries10 (33.3)10 (33.3)8 (26.7)
Maximum pain score with the injury6.8±2.2
7 (5.0–8.0)
6.6±1.8
7 (5.0–8.0)
6.9±1.7
7 (6.0–8.0)
Length of the pain palpation (cm)6.7±3.7
5 (4.0–9.5)
7.6±3.9
7.75 (4.5–10.0)
6.5±3.3
6 (4.0–8.0)
Width of the pain palpation (cm)3.4±1.7
3 (2.0–4.5)
4.4±2.9
3.5 (3.0–6.0)
3.7±1.9
3.5 (2.5–4.5)
No full knee extension deficit at rest2 (6.7)1 (3.3)0 (0.0)
Painful passive straight leg raise (yes only)30 (100.0)29 (96.7)25 (83.3)
Days between injury and intervention (days)1.8±0.9
2 (1.0–3.0)
1.8±1.1
1 (1.0–3.0)
2.3±1.1
2 (1.0–3.0)
MRI characteristics of oedema
Anteroposterior (cm)2.3±1.4
2 (1.4–2.9)
2.5±1.5
2.2 (1.4–3.0)
2.7±1.7
2.25 (1.2–4.1)
Anteroposterior (%)43.0±25.0
36 (24.0–52.0)
41.0±25.0
38 (26.0–51.0)
46.0±28.0
41 (22.0–66.0)
Mediolateral (cm)2.4±1.3
2.4 (1.2–3.2)
2.1±1.2
1.8 (1.4–2.8)
2.3±1.3
2.4 (1.1–3.3)
Mediolateral (%)53.0±28.0
47 (29.0–73.0)
48.0±24.0
43 (31.0–69.0)
50.0±24.0
51 (31.0–63.0)
Craniocaudal (cm)15.8±8.2
14.05 (9.1–23.0)
14.6±7.4
14.4 (9.2–20.2)
15.5±6.1
15.8 (10.6–20.0)
Volume (cm3)77.6±108.5
29.21 (9.9–82.0)
61.9±83.4
33.41 (7.4–64.6)
75.8±74.6
62.83 (10.0–135.7)
Cross-sectional area (%)28.0±28.0
17 (8.0–39.0)
24.0±23.0
15 (8.0–33.0)
29.0±24.0
23 (9.0–51.0)
Distance from most caudal ischial tuberosity (cm)9.6±7.7
9.4 (2.3–16.6)
12.0±8.3
11.9 (3.3–19.5)
9.5±7.0
8.7 (4.5–13.0)
Grade I17 (56.7)16 (55.2)13 (43.3)
Grade II13 (43.3)13 (44.8)17 (56.7)
  • *Data are either shown as mean±SD and median (IQR) for continuous variables or frequency and valid column percentage (%) for categorical variables.