Assessment of Hamstring: Quadriceps Coactivation without the Use of Maximum Voluntary Isometric Contraction

This study aimed to study the coactivation patterns of the hamstring and quadricepsmuscle groups during submaximal strength exercises commonly used in injury prevention in soccerwithout the use of maximum voluntary isometric contraction testing. This was used to compare:(i) the inter-limb differences in muscle activation; (ii) the intra-muscular group activation pattern and(iii) the activation pattern during different phases of the exercise. Muscle activation was recorded bysurface electromyography in 19 elite, male, youth soccer players. Participants performed the following:Bulgarian squat, lunge and squat. Electrical activity was recorded for the rectus femoris, vastusmedialis, vastus lateralis, biceps femoris and semitendinosus. No significant inter-limb differenceswere found (F1, 13=619;p=0.82;η2=0.045). Significant differences were found in the muscleactivation between individual muscles within the quadriceps and hamstrings muscle group for eachof the exercises: Bulgarian squat (F1,18=331:p<0.001;η2=0.80), lunge (F4,72=114.5;p<0.001;η2=0.86) and squat (F1,16=247.31;p