Biomechanical characteristics of preactivation and pulling phases of snatch lift

The biomechanical characteristics of 13 snatch lifts performed by 4 elite athletes were analyzed. Electromyographic data, ground reaction force index (GRFI), knee angular velocities, barbell velocities, and lifting time were obtained 0.2 s before the lift, for the first pulling phase (FP), and for the second pulling phase (SP). The preactivation, normalized electromyographic values correlated negatively with GRFI (p < .01). In the FP and SP, all of the parameters correlated positively with each other except lifting time. GRFI in the FP also correlated positively with GRFI, maximum knee angular velocities, and maximum barbell velocities of the SP (p < .01). In the SP, the ground reaction force reached its maximum first, followed by knee angular velocity and then barbell velocity. Barbell velocity reached its maximum before the knee and the hip joint were fully extended. When the correlation of parameters between the consecutive phases of snatch weight lifting was analyzed, it was demonstrated that the preactivation of trunk and leg muscles is important in the activation of the reflectory system in order to fully utilize the forces for generating lifting speed in the pulling phase.