Assessment of muscle volume using magnetic resonance imaging (MRI) in football players after hamstring injuries

ABSTRACT

Muscle injuries of the hamstrings are among the most frequent in football and a main cause for significant time away from training and competition. The purpose of this study was to prospectively evaluate the loss of muscle volume in recreational football players three and six weeks after initial trauma. We hypothesized that significant muscle volume loss occurs within 6 weeks after the initial injury event. Twenty recreational football players (mean-age=25 ± 4years; mean-height=181 ± 8cm; mean-weight=81 ± 10kg) with type3a (minor partial muscle tear) and type3b (moderate partial muscle tear) injuries were included. Muscle volume was determined using established methods for the hamstrings and the quadriceps femoris muscle within 3 days and after 3 and 6 weeks following the initial injury. The injured hamstrings lost 6.5% (mean=64 cm³(95%CI=31–98 cm³), p<0.001), the healthy hamstrings lost 2.1% (mean=21 cm³(3–44 cm³),p=0.096) of muscle volume after six weeks. The quadriceps in the injured leg lost 3.8% (mean=78 cm³(51–104 cm³), p<0.001) and 4.5% (83 cm³ (45–121 cm³), p<0.001) in the healthy leg. Muscle volume loss inversely correlated with activity levels in the healthy leg for the quadriceps (r=0.96 (0.90–0.98); R²=0.92; p<0.001) and the hamstrings (r=0.72 (0.40–0.88); R²=0.51; p<0.001), as well as the quadriceps in the injured leg (r=0.70 (0.37–0.87); R²=0.49; p<0.001), but not the injured hamstrings. Muscle volume ratio of hamstrings to quadriceps in the control limb was 0.52 ± 0.06 and 0.53 ± 0.06 in the injured leg. The rehabilitation period of six weeks did not have a relevant negative or a positive effect on ratios. Significant muscle volume loss in the upper thigh occurs in recreational soccer players within three, and within six weeks after a hamstring injury and lies between 2% and 7%.

KEYWORDS:

• Muscle volume measurements
• hamstring injuries
• muscle volume loss
• rehabilitation

Disclosure statement

Ida Bo Steendahl received funding from Deutscher Fußball-Bund Academy (DFB, German Football Association) for a scholarship within the international PhD programme “Science and Health in Football” located at Saarland University. All other authors have nothing to declare and there are no conflicts of interest.

Additional information

Funding

This work was supported by Deutscher Fußball-Bund Academy (DFB, German Football Association): [Grant Number no grant number].