Hamstring Muscle Fatigue and Central Motor Output during a Simulated Soccer Match

Abstract

PurposeTo examine changes in hamstring muscle fatigue and central motor output during a 90-minute simulated soccer match, and the concomitant changes in hamstring maximal torque and rate of torque development.MethodEight amateur male soccer players performed a 90-minute simulated soccer match, with measures performed at the start of and every 15-minutes during each half. Maximal torque (Nm) and rate of torque development (RTD; Nm.s–1) were calculated from maximal isometric knee flexor contractions performed at 10° of flexion. Hamstring peripheral fatigue was assessed from changes in the size and shape of the resting twitch (RT). Hamstring central motor output was quantified from voluntary activation (%) and normalized biceps femoris (BF) and medial hamstrings (MH) electromyographic amplitudes (EMG/M).ResultsMaximal torque was reduced at 45-minutes by 7.6±9.4% (p<0.05). RTD in time intervals of 0–25, 0–50, and 0–75 ms post-contraction onset were reduced after 15-minutes in the first-half between 29.6 to 46.2% (p<0.05), and were further reduced at the end of the second-half (p<0.05). Maximal EMG/M was reduced for biceps femoris only concomitant to the time-course of reductions in maximal torque (p = 0.007). The rate of EMG rise for BF and MH was reduced in early time periods (0–75 ms) post-contraction onset (p<0.05). No changes were observed for the size and shape of the RT, indicating no hamstring peripheral fatigue.ConclusionCentrally mediated reductions in maximal torque and rate of torque development provide insight into factors that may explain hamstring injury risk during soccer. Of particular interest were early reductions during the first-half of hamstring rate of torque development, and the decline in maximal EMG/M of biceps femoris in the latter stages of the half. These are important findings that may help explain why the hamstrings are particularly vulnerable to strain injury during soccer.

The assessment of neuromuscular fatigue during 120 min of simulated soccer exercise

“…Fatigue in soccer has been the subject of several reviews (Bangsbo et al 2007;Mohr et al 2005;Nedelec et al 2012) and experimental study (Andersson et al 2008;Oliver et al 2008;Rahnama et al 2006;Robineau et al 2012), however, a limited number of investigations have attempted to quantify the neuromuscular fatigue response, with equivocal results (Girard et al 2015;Marshall et al 2014;Nybo et al 2013;Rampinini et al 2011). Fatigue is classically defined as an exercise-induced reduction in the ability of a muscle or muscle group to generate maximal force (Gandevia 2001), which stems from peripheral and central mechanisms.…”

Reliability of measures of quadriceps muscle function using magnetic stimulation

“…Both calculations of %VA and CAR rely on the superimposed stimulation occurring during a plateau of the MVC, which is not always the case . Consequently, 2 corrections to the %VA calculation have been employed previously . The first defines the superimposed twitch size as the difference between the force following the twitch to the mean force 100 ms earlier .…”

Match-related risk factors for injury in male professional football

“…Most of the markers of player fatigue that have traditionally been examined in previous studies in this environment return to baseline values within 3-4 days after a football match and therefore probably do not explain the increased injury rate observed 5 days after a match [61][62][63][64][65][66][67]. One exception to this, however, is the biomechanical changes that have been observed after a football match or similar activity [125][126][127]. It has not been established how long these changes persist after a match, and future studies measuring biomechanical properties over several days after a match will have the potential to establish whether or not they could play a role in the observed relationship between match congestion and injury rates.…”

“…However, most previously published studies have shown that signs of muscular fatigue often disappear within 72 hours after a football match, [61][62][63][64][65][66][67] whereas the results of Paper III suggest an increased injury rate up to 5 days after a previous match. Other studies have shown that the biomechanical properties of muscles change as they are fatigued after a football match or similar activity, lowering the production of maximal force and altering the angle of peak torque [125][126][127]. This could potentially increase the risk of injuries as muscles are subjected to different activity levels and activity patterns [128].…”