ABSTRACT
Multiple exercises included in strength training involve greater activation of the quadriceps compared to hamstring muscles, which may lead to knee joint imbalances. The aim of this study was to examine the ratio of surface electromyography (sEMG) activity hamstring and quadriceps muscle groups (hamstring-to-quadriceps activation ratio; H:Q EMG), as well as lateral to medial hamstring activation ratio (LH:MH) in parallel squat, Romanian deadlift, hip thrust, lying leg curl and seated knee extension. The H:Q EMG was greater during lying leg curl compared to other exercises during both the concentric and eccentric phase, however the Romanian deadlift and hip thrust also resulted in relatively high H:Q EMG. Pairwise comparisons revealed that LH:MH was greater in the parallel squat compared to the Romanian deadlift and hip thrust in the concentric phase, and compared to the Romanian deadlift and hip thrust during the eccentric phase. Our data suggests that the lying leg curl promotes the greatest hamstring activation and H:Q EMG, amongst the exercises investigated, while also providing relatively homogenous LH:MH. The lying leg curl should be considered as a primary exercise in rehabilitation and training programmes, aiming to proportionally activate LH:MH and increase H:Q EMG, which may improve knee muscle balance.
Abbreviations
EMG | = | electromyography |
Semg | = | surface electromyography |
H:Q | = | Hamstring-to-quadriceps ratio |
LH:MH | = | lateral-to-medial hamstring ratio |
RF | = | rectus femoris |
VL | = | vastus lateralis |
VM | = | vastus medialis |
MH | = | medial hamstring |
LH | = | lateral hamstring |
HIS | = | hamstring strain injury |
ACL | = | anterior cruciate ligament |
MVICs | = | maximal voluntary isometric contractions |
RM | = | repetition maximum |
RMS | = | root mean square |
Acknowledgements
We also thank to Strength Training Research Group, all participants who participated in this research and made it possible.
Disclosure statement
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
Data availability statement
Raw data will be available upon request.
Data transparency
All authors make sure that all data and materials as well as software application or custom code support their published claims and comply with field standards.