Abstract
Context:
Epidemiologic findings of higher incidences of hamstrings muscle strains during the latter stages of soccer match play have been attributed to fatigue.
Objective:
To investigate the influence of soccer-specific fatigue on the peak eccentric torque of the knee flexor muscles.
Design:
Descriptive laboratory study.
Setting:
Controlled laboratory environment.
Patients or Other Participants:
Ten male professional soccer players (age = 24.7 ± 4.4 years, mass = 77.1 ± 8.3 kg, V˙o2max = 63.0 ± 4.8 mL·kg−1·min−1).
Intervention(s):
Participants completed an intermittent treadmill protocol replicating the activity profile of soccer match play, with a passive halftime interval. Before exercise and at 15-minute intervals, each player completed isokinetic dynamometer trials.
Main Outcome Measure(s):
Peak eccentric knee flexor torque was quantified at isokinetic speeds of 180° · s−1, 300° · s−1, and 60° · s−1, with 5 repetitions at each speed.
Results:
Peak eccentric knee flexor torque at the end of the game (T300eccH105 = 127 ± 25 Nm) and at the end of the passive halftime interval (T300eccH60 = 133 ± 32 Nm) was reduced relative to T300eccH00 (167 ± 35 Nm, P < .01) and T300eccH15 (161 ± 35 Nm, P = .02).
Conclusions:
Eccentric hamstrings strength decreased as a function of time and after the halftime interval. This finding indicates a greater risk of injuries at these specific times, especially for explosive movements, in accordance with epidemiologic observations. Incorporating eccentric knee flexor exercises into resistance training sessions that follow soccer-specific conditioning is warranted to try to reduce the incidence or recurrence of hamstrings strains.
Technical Performance Reduces during the Extra-Time Period of Professional Soccer Match-Play
