Kinetic Chain in Olympic Weightlifting
Imagine how useless a crane would be if the arm were not rigid, either because it was not strongly fixed (A), or because it bent under the load (B). The same issue exists when humans lift heavy weights. Both these situations are examples of a loss of kinetic chain. The force produced by the crane’s winch fails to lift the weight.
Lets assume that position 1 on the left is the lifter’s start position for the pull. If, at the start of the pull, the lifter loses rigidity of the spine (position 2), there is a loss of kinetic chain. The force produced by the legs is not fully transmitted to the bar, resulting in failure of the bar to rise while the spine is bending. If, at the start of the pull, the lifter’s hip rise faster than the shoulders (position 3), there is also a loss of kinetic chain. Some of the force produced by the legs is wasted, thus the bars upward movement is compromised.
Kinetic chain is a significant concept in Olympic Weightlifting technique. The concept is all about minimising the loss of force transmission through the body, not just in the pull but also in supporting heavy weights overhead. This is why beginners must learn about posture and spinal shape and to practise bracing the body under load. The need to maintain kinetic chain is why it is fundamentally necessary to keep the angle of the back the same as the bar rises from the ground to the knee. It is why lifters must learn to brace the body in the dip and drive for the Jerk, or the receiving position in any of the Olympic lifts.
