Effects Of Kettlebell Load And Swing Style On Female Hip Joint Kinetics

Kettlebell (KB) swing exercise, whether performed using half (HS) or full (FS) swing variations, are posterior chain dominant exercises, particularly requiring hip extension contributions when performed correctly. While FS swings are used in competition and believed to elicit a greater training stimulus, HS swings are safer, particularly for novices. PURPOSE: To evaluate the effect of KB mass (12 kg, 16 kg) and swing style (FS vs. HS) on hip extension joint kinetics through the assessment of net joint moment (NJM), impulse, work, peak power, and vertical ground reaction force (GRF) characteristics in young adult females. METHODS: 15 physically active females (29.8 ± 5.3 years) volunteered to perform 15 swings under 4 conditions: HS/12 kg, HS/16 kg, FS/12 kg, and FS/16 kg. All participants were and had been incorporating kettlebell swings into their training programs for a minimum of 6 months. A camera motion capture system captured dominant limb foot, shank, thigh, pelvis, and KB position while two force plates collected GRF. Hip joint kinetics were computed using inverse dynamics. GRF characteristics were computed using the total GRF vector. RESULTS: Compared to the HS, FS peak KB velocity was 16.6% higher (P < .001, d = 2.1). Neither style (P = .608, d = .10) nor mass (P = .259, d = .31) significantly influenced hip NJM impulse (interaction: P = .527). Hip peak power was 37.2% greater (P = .001, d = .54) for FS compared to HS. Hip extension work was 21.9% greater for FS compared to HS (P = .006, d = .39). Hip peak power was 34.8% greater for the 16 kg than the 12 kg KB (P = .010, d = .72), whereas peak KB velocity was 2.7% greater for 12 kg compared to 16 kg (P = .003, d = .36). FS GRF impulse (14.7%, P = .002, d = .73) and peak (7.0%, P < .001, d = .49) with the 12 kg KB mass were greater than HS but neither impulse (3.7%, P = .445, d = .20) nor peak (2.4%, P = .108, d = .18) were significantly different between styles with the 16 kg KB mass. For HS, 16 kg KB GRF impulse (15.2%, P = .018, d = .63) and peak (6.3%, P < .001, d = .44) were greater than 12 kg, whereas there was no significant difference between masses for FS GRF impulse (1.9%, P = .645, d = .10) and peak (1.2%, P = .384, d = .09). CONCLUSIONS: Athletes hoping to achieve a greater training stimulus may prefer to incorporate FS over HS in their training regimens due to the required greater hip work and power, and KB velocities.