Hamstring myoelectrical activity during three different kettlebell swing exercises

Kettlebell exercises have become an increasingly popular form of resistance training and component of lower body rehabilitative training programs; despite a lack of scientific literature illustrating internal mechanisms and effectiveness of these approaches. Participants (n=14) performed three different styles of kettlebell swings (hip hinge, squat and double knee extension) and were assessed for medial hamstrings (MH) and biceps femoris (BF) myoelectrical activity via surface electromyography (sEMG). Bipolar pre-gelled Ag/AgCl surface electromyography (sEMG) electrodes (10mm diameter, 20mm inter-electrode distance) were placed on the participant's dominant limb after correct skin preparation.There was a main effect for swing type (p = 0.004), where the hip hinge swing elicited a greater overall MH and BF sEMG in comparison to the squat swing (mean difference = 3.92; 95% CI = 1.53 to 6.32; p = 0.002) and the double knee extension swing (mean difference = 5.32; 95% CI = 0.80 to 9.83; p = 0.020). Across all swing types, normalised percentage of MH sEMG was significantly higher compared to the BF (mean difference = 9.93; 95% CI = 1.67 to 18.19; p = 0.022). The hip hinge kettlebell swing produced the greatest amount of hamstring sEMG for the three styles of kettlebell swings assessed. These findings have implications for the application of kettlebell swing exercises in strength and conditioning, injury prevention and rehabilitation programs.