Comparison of the Electromyographic activity, Quadriceps: Hamstring coactivation ratio and strength changes of dominant leg muscles in collegiate football and volleyball players during different forms of exercises

Abstract

The preliminary study was aimed to compare Electromyographic (EMG) activity, Quadriceps: Hamstring coactivation (Q: H) ratio and 1- Repetition maximum (RM ) squat changes of dominant leg muscles in collegiate football and volleyball players during different forms of exercises. Surface EM G analysis was carried out in 24 university level trained male players, football (n=12) and volleyball (n=12) while performing the following exercises: unilateral bridges, lunges, lateral step up to a 20.32 cm (8 inch) platform, quadruped arm/ lower extremity lift in the first session. The EM G activities of vastus medialis obliquus (VMO) and hamstrings muscles of dominant leg of the players of both groups were recorded using Power Lab EM G system (Lab Chart, AD instruments, ML -818, Australia). On the next session, 1-RM squat tests were also performed on the same players of both groups. In footballers, the lateral step-up, lunges and quadruped arm/ lower extremity lift and in volleyball players, only lunges produced EM G levels greater than 45% maximum voluntary isometric contraction (MVIC) in the VMO, which suggests that they may be beneficial for strengthening that muscle. All the exercises produced EM G levels less than 45% MVIC in hamstrings in both groups of players, so they may be more beneficial for training endurance and stabilization. The study also revealed smallest Q: H coactivation ratio in all exercises in volleyball players suggesting more hamstring activity than quadriceps but in footballers, moderate Q:H coactivation ratios were obtained establishing the quadriceps dominant activation in all these exercises. The 1- RM squat testing also showed significantly greater value (p=0.00) in football players than volleyball players. The findings in this study may be used to select specific exercises to enhance a core training programme depending on the individual needs of an athlete or as per the requirement of the specific sport. ABSTRACT FROM AUTHOR