Biomechanics of the clean and jerk in weightlifting national Jordanian team

Abstract

Seven elite national Jordanian weightlifters were videoed at 50 fields per second from the sagittal plane during the execution of the clean and jerk (C&J) on an AMTI force platform with 3 weights of submaximal lifts; low medium and high weights (35%, 65%, 85%) of their maximum. Linear and angular kinematics of the barbell with the ground reaction forces histories of the lower body were analysed using Kinova & APAS. A significant decrease was found in the maximum vertical velocity of the barbell during the second pull of the heaviest lift (p < 0.05). Maximum extension velocity of the hip joint significantly increased during the first pull of the heaviest lift (p < 0.05). Vertical velocity and maximum bar height decreased during the second pull, especially at 85%. Angle-angle diagrams of the knee and hip profile showed major differences among participants, especially at the 85% lift of their maximum.

Comparison between Olympic Weightlifting Lifts and Derivatives for External Load and Fatigue Monitoring

“…The Snatch requires a weighted barbell to be lifted from the floor (usually using a wide grip) to an overhead position in one continuous movement [ 3 ]. The C&J is divided into two main phases, in which the first requires the barbell to be raised from the floor (using a shoulder-width grip) to the front of the shoulders in one continuous movement [ 4 ], and the second phase consists of a jerk, in which the barbell is propelled from the shoulders to arm’s length overhead by forces produced primarily by the hips and thighs [ 5 ].…”