Background Hamstring injury (HI) is the most prevalent muscle injury in both amateur (van Beijsterveldt et al., 2015) and professional (Ekstrand et al., 2011; Hawkins et al., 2001) soccer (football) players. Worryingly, the annual incidence of HI increased by 2.4% annually between 2010 and 2014 (Ekstrand et al., 2016)

Setting Professional football.

Patients (or Participants) Twenty-two semi-professional football players (Mean ± SD: Age: 19.3 ± 2.9 year; Height 185.0 ± 8.7 cm; Body Mass 81.6 ± 6.7 kg) participated in this study.

Design All players were right dominant (defined as their preferred ‘kicking’ leg). Subjects were included in the study if they were not injured or rehabilitating from an injury at the time of testing.

Main Outcome Measurements The eccentric hamstring strength of players was examined using the Nordbord (Vald Performance, Queensland, Australia) device prior to soccer match and immediately following 90 minutes of football friendly match.The season period of the research project was the second half of the season.

Results There was a significant difference of moderate effect in eccentric strength before a match (M = 306.91, SD = 59.26) compared and to after the match (mean = 277.77 ± SD = 60.35 p =.000, Cohen’s d = .50) (table 1). The eccentric force before training (mean = 306.91 ±SD = 59.26) and after training (M = 277.77, SD = 60.35 demonstrated a significant moderate effect(p =.000, Cohen’s d = .50).

Conclusions Etiological risk factors attributed to an increased risk of muscular injury include poor muscular strength, particularly eccentric strength deficits, and ipsilateral muscular strength imbalances. Resistance to fatigue and eccentric strength, particularly at high speeds should be given greater consideration in conditioning for soccer. The small number of participants limits the global generalization of our findings. However, this limitation is tempered by the inclusion of professional players in our study.